Worked on a huge permanent lighting installation some years ago where the electricians that had installed it swapped the Earth and Neutral on every single fixture plug. Drove the audio guys nuts trying to figure out where that hum was coming from, since all the audio gear was correctly referenced to Earth.
I have a basic one, because when you're renting it's really handy to be able to look at a property and quickly find out whether the electrics are vaguely trustworthy. Missing earth on GPO is common, but I once found a reversed live and neutral which only became a serious problem when the real estate agent present said "if it was a problem I'm sure the owner would have fixed it"... see ya.
Had an outlet that wasnt working. Maintenance guy held a non-contact voltage detector to the outlet "Nah its live" I left shortly after because maintenance in general was lacking and they wanted to raise rent. AC/heat pump would leak out in 2 months, one sink in the kitchen was missing a P-trap, etc.
The 2.5 megaohm resistor across the LCD is to clamp any stray voltage across the LCD. They require almost zero current to operate, so almost any stray electrons will get them to activate.
We had a metal sided garage built at our local scout camp. It was in operation for about 10 years when last summer i happened to be in bare feet and leaned against the siding and felt a mild shock! Thought I was imagining things so I had a friend do the same thing with identical result! Turned out to be a combination of two things. When they wired the garage pony panel they brought over the two live wires and neutral but no ground and no one ever put a0 earth ground wire into the panel, as a result the entire building was a floating ground! Combine that with a poorly installed thermostat for electric heat that they managed to install crooked enough so one of the line wires could touch the box side. No earth ground so breaker did not blow but result was that the entire building shell was at 110v with respect to ground and I was the first to discover it after 10 years of use!
Yikes. I was noticing some floating grounds all around one building I worked on (US) and decided to do bootleg grounds after a thorough!!!!!! And proper testing of polarity ( I open the main panel verified everything and connected to a known good service outlet that I checked and ran extension cords all around the building and checked every single outlet and switch, thankfully in a small building) as I could see the refrigerator floating at 1-10 voltage and something else metal floating at another. so there is a lot of "main panels" all over this building now but I feel that's safer than having no ground and all exposed metal work that could become live any at different potential. This was an old building where they upgraded the electrical panel when we moved in and then ran the old panel as a subpanel, I suspect most of the wiring is 2 core no ground pretty much everywhere except for in the kitchen And where it was updated? of course, only in accessible places. Edit, AND DON'T DO IT. Maybe I should explain for foreigners where ground pins are required because they make so much more sense! In the US allot of older homes,,,, have 2 prong outlets. you can use an adapter that plugs in and gets screwed on, however nobody ever screws them on and you never have them when you want them so…. there's a very large tendency to break off the ground pin on a 3 prong device ( computers, audio equipment,,, ) everything if you work or live in a two-pronged outlet building. options other than breaking the prong off ( Not Code ), is to hire an electrician to replace everything ( Code $$$$$$ ), replace it yourself ( can be Code if correct ) or just change the outlet from a two-pronged to 3 prong and not do anything at all and lie that it's fixed ( Not Code ). install a GFCI in the breaker panel ( if one exists for your old nonstandard panel ) / ALL locations ( Code $$$ ). or what is called a bootleg ground ( Not Code, as it breaks the one bond rule ) which will pass the house inspectors 3 digit light tester if they don't know any better, it's also good for realtors. So do you have slightly miss wired outlets or have people going around breaking ground pins and developing a really bad habit?
Many years ago when I was at university I built an RCD tester that had a resistor to ground. The room wasn't on an RCD so I told my room mate DO NOT hold the button in. A while later I left the room. On my way back I heard a loud bang and on returning to the room I saw a cloud of smoke and my room mate sitting on the other side of the room, trying to look innocent.
I work on the distribution side in the UK. When I'm doing the cut out change we plug one of these little things in just as a basic test we go for the nearest socket to where I am working. Out of 10 houses 1 will have a a fault on the socket most are cross polarity in the socket.
The LCD warning needs around 3-6VAC across it to operate at 50/60Hz to fully dark, so any voltage over around 50VAC will operate it reliably once you take into consideration the high value series resistors also there. The diodes are there to protect it from high voltage breaking down the thin film of liquid crystal in there.
I have a neon one with a resistor for GFCI testing and button to shunt it. Tiny thing that seems to work really well and impossible to plug in wrong unless you completely disable the safety.
5:10 That function is mandatory in testers in Finland. Old wiring was often done with two wires with earth connected to neutral in the socket. Sometimes when laymen did illegal wiring they actually connected the earth to the line instead. Such connections have caused fatalities, latest in 2015. Also four non-fatal accidents since 2012. In four four the five cases it has been caused by a mirror cabinet in the bathroom. Those are real shock dispensers. I would ban sockets on those or at least allow just euro socket for a tooth brush.
Our home is on a TNC-S system (as are all the other homes in our area). Mind you we're pretty rural (even by Aussie standards). Always beneficial to ensure the earthing rod's kept "well-watered" for pretty obvious reasons, which can be difficult in our parched environment!
Our system was originally TT (local earth only), then a few decades ago we combined local earth with neutral (so an upgrade to TN-C-S). We still have the local earth rod, and I've noted that if we disconnect the rod, earth loop impedance is pretty high, so I keep the rod connected, and "well-watered" as an added safety measure. Useful when the nearest "real" hospital is over 100km away . . . . . . .
If memory serves the single-segment LCD is a copy of an earlier Beha branded unit which was the first to check polarity, the Germans having decided this was *absolutely necessary.* The LCD is a reasonable way of indicating a voltage differential using a low current, replacing a neon. It is more visible than a neon in most lighting conditions. Of course once you have a microprocessor in there (like the SOK36) you can use power from the mains to drive an LED without exposing the user to unsafe accessible currents.
That must be why I don't like Flies Graveyards, because there are too many Currants in them, and they are too square. They need to loosen up and LIVE it up a bit in life. Ohm My God that was a terrible joke, may I say so myself. Though I like to AMP things up, to create a spark of AMPmosphere in the joint.
There is a condition that can occur when some scroat has been at the copper in the local substation and the Neutral is disconnected from the Earth! The effect is that the Neutral "floats" at a point somewhere between the 3 phases (dependent on the load the houses put on the system)! This gives not only a random Live to Neutral voltage but a voltage can be generated between the earth terminal and the body of earth. Not a usual occurrence but ......
I've had a voltage probe screwdriver (Yato YT-2863) which had "LCD voltmeter" working in an interesting way: There was a resistive voltage divider wired to the LCD connected to the "inductive test" path which lit up sections showing predefinied voltages (12, 36, 55, 110, 220 V). Measuring approx. 220V would light up 12 to 110V and 220V would be very faint. Once I've disassembled it to check how "indictive test" works I could never reassemble it to make it work again :) Now I have an insulated screwdriver. Oh, and "inductive" path looked like it was actually "conductive"...
Here's an idea anyone could take; Make a version of this with a multi-coloured LED with individual colour channels (rather than colour triggered by software in a microchip). or individual red, blue and green LEDs. Then when plugged in, "Yellow" could show the "OK" state, while all other colours represent an error state. For the earth leak test like on the generic green model shown, make it light red, and include a piezoelectric buzzer which will only chirp briefly for error states.
In Finland only testers that have a reference to actual ground by touching are allowed. Here many sockets are grounded by connecting neutral to ground on he socket. If one instead accidentally connects the line to the ground a socket tester that just compares the voltages does not detect it. I may show mixed neutral and line but that is not a critical error here.
Seeing the schematic with the neons reminds me of once when I was young (and stupid), I tried connecting a neon lamp directly to mains with no resistor. I'd measured the resistance of the bulb with a meter and it basically read infinite ohms so I thought "well, with a resistance that high it's never going to have much current going through it, so I don't even need to use a resistor". Bad idea! I didn't know about the way the resistance drops quite low when the lap is lit. Got a bit of a bang.
At 4:41 Clive says "I have slight lag on the main RCD to avoid it tripping" can you explain how ? I have the same problem with my workshop. If I accidently cause a trip, the trip in the house that runs the workshop fires and not any of the trips on the workshop consumer unit and it's flippin annoying.
+Joe Farr You get a type S RCD with a slight delay to allow instant RCDs to clear the fault first. On events we use multi-layer RCD protection with programmable RCDs. They're quite expensive though.
I had an old neon Daniel Woodhead tester. The plastic base for the prongs finally degraded and it fell apart. I admit I was surprised how simple it was inside. Anyway, I bought another one.
You can find the common "Cheapie's" most places but building code requires the use of "Arc Fault" breakers to be used through out house now. So as an electrician we have to buy the ones that check correct wiring, GFCI's (wall device or breaker), and Arc Fault (device or breaker), all in one tester.
bigclivedotcom they started using them here for fire protection really. Example: lamp on night stand next the bed gets knocked over, when the lamp hits the floor the glass breaks and of course there is a large current draw as the filament burns up due to it being exposed to the O2, their theory is that if the filament doesn't break fast enough it could lay on something like carpet and continue to burn that's where the arc fault kills that circuit as soon as it sees the arch. It all started in California where most of our NEC codes take root.
Hi Clive, if you keep your finger on the RCD test button, the resistor will not get hot if you are testing a properly functioning RCD. The RCD will trip and the voltage across the resistor will be switched off.
My reference to dissipation was if the unit was used on a circuit with no RCD, a malfunctioning RCD or one set for a higher current. It's human nature to just keep the button held in when a test fails in the hope it might suddenly work again.
Can you make a video about why UK and US plugs are polarized? In Germany the plugs aren't polarized and are still perfectly safe. I guess it's because having a fuse in the plug requires polarization?
It certainly makes Edison screw lamps safer as they can be designed such that live is always recessed into the fitting rather than the screw thread being live. Probably lots of other situations where its safer to have a known live and neutral. There's probably (slightly dodgy) devices out there that have a switch on one wire going into the device, if its polarised then it can be on the live wire and make the device safeish rather than appearing off but still being live inside.
Ross Mitchell, Edison sockets are polarized in Germany (and surroundings). The wires going to the German sockets are also polarised. It's just the sockets themselves that aren't polarised: there's no regulation on which wire should go where, and you can put in a plug both ways. French plugs strangely also have no polarization regulations, but plugs only go in one way there. I believe that since we all have earthed devices now, it's not so important to polarise the plugs: you can always make a device safe with the earth.
+whuzzup, Any 2 pin plug that feeds mains into a device will be polarized, at least newer equipment anyway. Things like your phone charger usually aren't polarized though.
I've been watching for awhile now, and this is the first time I have heard you mention (or the first time I understood you to be mentioning?) the different kinds of grounding/earthing that are commonly used. It seems that here in the USA we use the TN-C-S Earthing System? And the chart on the page I am looking at now shows that Great Britain uses TT and TN-C... I never realized that this was so different. I knew that you British called the 'ground' pin 'earth', but I thought that was pretty much the extent of the differences -- other than the voltage difference, and the fact that you guys in Britain use 50 Hz rather than the 60 Hz that we have here in the USA. I know higher voltages can jump farther distances as well, which makes me wonder why Great Britain went for 220V rather than the 110V into the home wiring of every plug in the home? I know the USA would have needed to make a LOT of stuff obsolete overnight to switch to 220V, so it was never going to happen. But it seems like Great Britain was more able to choose between 110-120V or 220-240V standard, and clearly chose the higher. I know we can get to 220V by using both of the phases -- and usually do for things like home electric water heaters and the kitchen electric stove. Most everything else, though, is 110V here in the USA. It seems like all of your 220V electrical components would need to be 2x as 'tough' (robust?) (compared to same component in 110V variant) to withstand twice as much voltage -- either flowing through it, or being held back from flowing, etc. I know that doesn't necessarily translate into 2x the cost, but still. What's the benefit from having everything running at 220-240V rather than half of that? If I were to accidentally grab a hot wire, I damn sure would rather it be 110V @ 60Hz instead of 220V @ 50Hz! Sure, you're 10 cycles less per per second, but that's still 50 cycles that are at 220V!
@@bigclivedotcom Every time I have a failed thing that has the "Made In China" logo on it I expect to someday see bugs crawl out of it. Are you going to have any planned explosions this summer?
Clive, i'm really not sure this new lighting is working. The top half of the video looks rather overexposed, especially the notepad. Maybe its just the exposure on the camera needs to go down a notch. Or maybe the lights are in a slightly different place to the previous ones?
Won't the vast majority of the voltage be across the resistor rather than the switch? It would form a voltage divider between the resistances of the resistor and the switch.
Motorman2112 once switch is fully closed -yes. Problem starts when the switch is released and there would be sparks. With enough sparks you have ionized air that would attempt to keep a conductive path open. One saving grace is AC voltage the other is a functional RCCB/GFI/RCD. Pushing this button repeatedly in a non-GFI environment might trigger a nice ion channel / little plasma cloud that potentially stays hot enough through 0-volt crossing and burn out the resistor in a spectacular way.
I have one that I got at Home Depot. Like the green one in the video, it also has the button which shorts to ground so that you can test GFCI. I use it every time I wire a socket, but I originally bought it to help me figure out why stuff plugged into this one outlet would always shock me :)
It was a floating ground combined with a misbehaving ballast in a fluorescent lamp on the same circuit. It would come and go as I turned on or off the lamp (but I hadn't made that connection), making it surprise me once in a while.
They also make a much simpler one that is sold at any hardware store in the US. It has three neon lights that light up to tell if you have any of the problems Clive was talking about. It is the classic triangle circuit. I have one and it works well. It was under $10 US, so yes they do make them for the US and you can get one at any hardware store.
I should get one of these testers as I'm sure somewhere along the line, the live and neutral is swapped somewhere as my bedroom lamps when turned off can provide some entertainment with just touching the outer casing of an LED bulb and they glow slightly, and from previous experience, they're only switching the neutral (despite the lamps being wired correctly) which I discovered after getting a shock off one when poking a broken LED filament bulb and managed to trip the power in the house... :P
On the Socket&See and the HandyMan there is a double insulation mark but the earth terminal goes into the housing. Has far as I know, an earth wire is not allowed on a double insulated apparatus.
Yes, you're probably right and I don't know the GB regulations. In the Netherlands double insulation means: No earth wire in the cable and a 2 pole power plug. Even not a 2 wire cable with a eathed power plug because you can get the impression the device is earthed. btw There is no fuse in the tester you took apart, does that mean the 0.5mm wires are behind a 32 Amp fuse? That could end nasty!
The earth thing you talked about where the voltages around the house can get wonky must have been what happend at my folks house. Windstorm knocked a tree down on the line and the power went out. They came and fixed it and after about 2 hours suddenly the lights in half the house got super bright and the other half dimmed superbad, blew up all the TVs and some of the kitchen appliances in one half. The voltage in one half of the house was ~150v and the other half was about 85v (normal 115v supply.) The power company claimed there was no possible way that it could have been their fault and would not cover any of the destroyed appliances as a result. But the problem mysteriously vanished when they sent some guys out around 1am in the morning to work on the line in the dark.
I'm in the process of building one of these with 7 watt equivalent LED c7? lamps as the indicators, as my neon tester was far too dim out in the brilliant sunlight. I'm also going to include a voltmeter in it, and a test function for the one lamp thats usually not lit I got a double pole switch and it just made sense to add the extra wire. So I will be able to plug this in at an event and leave it plugged in and if it's too bright I'll be able to turn it off and still see the voltmeter kind of like a rack mount power distro would do but a whole lot more useful and portable.
I wouldn't recommend that. The reason Fluke recalled all their units was because the test current meant that if the ground connection was broken in a circuit there was a risk of a high enough current shock on associated metal to cause muscular contraction and stop people letting go.
Oh it's a reply, Oh it's a reply from the master of all things Chinese and electric, Oh wait I think you might have replied to the wrong thing? Or maybe you're referring to my comment on the other comment / video? for N-G Bonds? Oh "Why Fluke are recalling their SM100/200/300 plug-in testers."Just happens to be in my recommendations list, I thought I watched it. although I am still in the design/parts stage and I haven't ( it's getting close ) wired anything up yet, so any input is appreciated. I'm using a panel mount voltage display and my only concern is the current draw of the ground LED and possible tripping of GFCI's, i am planning to test that yet and might need to current limit. its a pretty simple design without my complications, it's more or less the triangle with an on-off-(ON) switch on the hot that will toggle between hot on/off and test of ground by swapping the ground lamp from ground to hot. some more parts came in earlier this week so it was kind of fitting for me to see that there is a video on the subject recently posted. I have drawn out my schematic coming up on almost a year a go now. I have most of my parts except for the light bulbs and a clear/transparent case. Which I decided to complicate my connections by adding in a IEC C14 connector and a circuit breaker for the pass-through IEC C13 and NEMA 5-15 output connectors. for some reason I like things with pass-through plugs. www.dropbox.com/s/l3lu0yfwjs93ufi/2019-03-20%2001.54.59%20BCV.jpg?dl=0
Eight Watts Hot. Love it. Clive can you some day go into detail how the US power systems differ from the UK? For us if I want 240 I have to use L1 and L2. For you is it just L1 ? Like I said can you please do a video on this? Thanks
I would really like it if Clive could do a video on how they do differ. He has a way of presenting things so that they are easy to understand. My 3Ph understanding ends at if the motor is running the wrong way just swap any 2 legs and your going the other way. I don't know anything about the feeds from the street out to the sub-station. Neutral does come in from the street along with L1 & L2. The stuff like stove, electric water heater and the electric dryer tend to be 240v and any heavy use shop type things may also be 240v L1 + L2. But really I know just enough to be dangerous.
In my house only live ant neutral come in and the neutral rail is conected to the ground which is just a screw into the foundadion of the house. They call it a Pe-N type circuit here in sweden. I found that pretty strange but aparently it was conmmon at the time when my house was built since very few appliances were required to have earth at all other than wet spaces.
rimmersbryggeri This is the normal type! Never the power company sent "saved earth" to a house from outside. Normally after the Wattmeter the N change to N and SE. Then main switch, RCD, ...
I dont think it is the normal way in sweden anymore but my house is so old it had no earth before I put it in other than for kitchen fittings and the light in the bathroom I think. I think now there will be a separate earth rail in the consumer unit and RCD/GFI is mantatory.
Have Poundland stopped selling the 1A USB phone chargers? Icoudn't find and and the staff said that they have stopped doing them? Anyone recommend an alternative? My Son in law looses them every other week, t/hey were a nice safe cheap replacement.
So that explains why the house I worked on a few months ago (not on the electrics, but floor screed) was a shocking experience. Every (steel) window frame, every decorative rock/boulder, even the walls gave people a good jolt if we were either walking around in our socks (to protect the new wooden floor) and touching a surface while grounded in some other way, maybe one hand on a water pipe or something... Bloody electrician....
The diodes in series with the LEDs won't protect them from reverse bias because the reverse voltage will be across both the LED and the diode, and the LED can't tolerate a significant reverse voltage. The correct design is to put reversed diodes across the LEDs
The older gallium arsenide LED technology is resilient to high reverse voltage. It's not uncommon for cheap indicators to use a simple resistor and LED.
I think my neon mains tester is even simpler than yours. Only one neon and resistor inside a knob that turns and selects N-L, L-E, E-N in turn. Using it here in France via a travel adaptor caused confusion until I realised that those adaptors reversed N and L. Doh!
I love how it has a max voltage of 230... Most mains is now around 240-250 volts. The days of 220-230 are over. Same thing in North America, everything that was 110-115 is now 120-125.
In the US, it was ALWAYS 120/240. 110 is the _minimum_ acceptable voltage, and 120 is nominal, with the voltage usually ending up around 118 volts. So, people saying 110 are actually only talking about the lowest acceptable voltage to drive whatever your device may be. (Or just don't know anything about what they're discussing) As for Europe? No idea. It's been long enough since I researched it that I'm certain the EU has invented new standards because they can't stand leaving anything alone.
Troy Belding nope. It actually was 110 in the early days of AC power. It later went to 115, then 117, and finally, 120. The allowed tolerance is +/- 5%, so the minimum is 114 and the maximum is 127. Typically, unless you're way out in the boonies somewhere, you'll find that the no-load voltage is about 122v, which allows for voltage drop from high current appliances or long runs of wire between the breaker box and a distant outlet. Be glad we're not in Japan. They have 100v nominal, but in the northern half of the country is supplied at 50 Hz, while the southern half is supplied at 60 Hz. Which means that if you move between regions, you have to replace any appliances that are frequency sensitive.
Yes and no. The early days of AC power varied depending on the region. Chicago would have one, Boston another, and eventually the smaller regions sort of gave in to the larger regions. By 1963, device voltage was 115. in 1984, _distribution_ voltage was set to 120. Some sources talk about Edison using 110 distribution for 100 volts for his bulbs, but that has to have been come up with by someone who didn't understand that Edison hated AC. AC current was _Tesla_. Edison thought everything should be run on DC current. So, basically, 120 has likely been the 'true' distribution voltage since the 30's, and they just nailed it down in the 80's. In Houston, the 'no load' voltage floats right at about 118-119, in most areas. When I see 112, I start being concerned, and the few times I've seen 108 and similar, I had the customer call in an electrician. (That was when one person killed three computers with her under-desk heater)
Panels in the us/canada are 120/240, but receptacles are 125/250.... the voltage is usually closer to 125/250. depends on how many transformers are providing power along the lines to the houses on the block. A lot of new construction has several smaller transformers installed in closer intervals linked in parallel to share loads more evenly. In the past there would be a few large transformers spaced farther apart and if the load would be high customers farthest from the source could experience significant voltage drop, I have seen 105/210 with the A/C and stove on, It was a 200 amp service drawing only 82 amps..... to much distance from the transformer to the house and to many houses on the same transformer.... the lights in that whole area flicker like Christmas tree lights
Here in Poland, most sockets are Type E, with sockets for live and neutral, and an off-center pin for ground. Double sockets have both ground pins toward the center of the socket, and so you have to invert one of the plugs to insert it. This inverts the live and neutral. Shouldn't this cause polarity problems?
Hi bigclivedotcom, how about making a video about these "arc fault circuit interrupters", aka AFCIs? They are becoming "fasionable" these days, at least where I live and legislators are already considering making them compulsory in certain situations. I really liked your videos on RCDs, so I think doing an AFCI teardown and explaining its function and principle would greatly appreciated!
Thanks for your reaction! I'm from the Czech republic and we are using 230V (though in reality the voltage is often about 240V). Though I've heard that with the "ring main" you use the UK, less arcing faults tend to happen, because there are two paths and the electricity will use the more solid one instead of arcing... So maybe that's why they would be less useful in the UK...? Not sure. I've learned about AFCIs from local Czech electrician forum recently and I can't decide if they are overrated or not. My impression so far is that they are a hype and it's mostly ABB and other big manufacturers pushing for AFCIs to be required by the law, in all households. I'm really confused, because while the idea seems legit, I suppose many devices like motors with brushes make tons of arcing in a controlled manner and are absolutely safe. But if the same arc was happening "in the wild", it could easily melt something or set it on fire. So either a lot of nuisance tripping or not much real protection at all. But maybe I'm missing something. That's why I thought it would be really great to hear what someone as experienced as you thinks about them :). Anyway, keep up the good work!
you know Michael Faraday’s magnetic induction experiment where electricity is generated by placing a bar magnet in a coil of copper wire. what happens if two diodes were placed in the wire to block the electricity from escaping in either direction? 🤔
Getting "earth leakage" mixed up with "RCD" and ending up with "arse leakage". Also, the power rating on the trip-testing resistor probably doesn't matter much. Since if your mains supply is any good, pressing the button instantly cuts the power anyway.
Yes, I'd like to know how they measure loop resistance. My guess is that they put a pulsed load between live and neutral and measure the voltage drop, which is not a trivial circuit.
Dear Clive, after watching your very useful video, I decided to buy a socket tester. I looked on Amazon. They have two types made by Socket and See: the SOK36 Professional is £51.95, the SOK22 Craftsman is £19.96. Would you recommend one of these -- or another brand? Best wishes, John in the Peak District.
If you just need a basic tester then a cheap simple one will do. If you are working in an environment where the loop impedance test is needed then that's a good option. For personal home use I'd suggest something simple like the simple three LED and test button type. For professional use the one that does the loop impedance test is useful for a quick test. It's worth noting that the electrical distribution industry issues the loop testing one to their meter installers to use as a quick check.
Yesterday I opened the Amazon Basics calculator I have to see if the PV cell on the front was real or if it's a fake cell. It's a real PV cell! It's wired to the circuit board and when I pulled the silver oxide button cell out of the holder, the PV cell (with enough light) powers the calculator! I expected the PV cell to be faked (I think Dave Jones also did a video on this.)
the funniest fake solar calculator i have is one that has a see through case. You can literally see that the solar panel is fake while its still inside its packaging. Bought it though because it was like 1€. Well, i think its real but not even any wires attached to it.
The solar panel is connected to the battery via a germanium diode ( yes Ge diode, not Shottky) and there is a red led across the battery in case the cell is removed, though some models use a little blob containing 4 silicon diodes in series instead to give a 2V voltage clamp. The solar panel in any case can only deliver under 1mA in bright sunlight, so the tiny alkaline cell in there ( generally a LR44 or other small button primary cell) will never be overcharged, unless you leave it outdoors in full sun for a month, which will melt the case anyway. Indoors the panel only provides a tiny top up to the cell, and in any case those calculator chip run on a LR44 for about the shelf life of the cell anyway. Those with a single AA cell in them I generally use a cell that will not run a clock, and in the calculator it runs fine for years.
That LCD looks re-usable for other applications. The RCD test gave me an evil idea to build a microcontroller based "random power disconnector" that would trip the RCD randomly :>
Unrelated, but... I have a Yihua 937D+ Soldering Station, the middle digit on the display is screwed up, the iron seems to heat up and work though - the seller gave me a 70% refund... Just wondered if you had any ideas, - I had look and can't see anything obviously faulty, or dry connections etc...
Does it light or display what looks like all the other digits combined or a combination of two. It sounds like a solder bridge defeating the multiplexing.
I thought that, as the left and right digits work fine, the middle one displays random segments, some brighter than others... I have some pics (and a small video) if you got an email address and/or forum :)
In germany for the TNC (C=common neutral+earth line) system gnd/earth has to be 10mm² until its seperated into Neutral+Earth = TNCS (or then TNS, s meaning separate), so you cant really say its cheap to keep it that way.. and you really have to try hard to brake the 10mm² common neutral+earth connection ;-) The T-T (earth at incoming point, earth at machinery)System most of the time is only used in industrial applications where you set your ground/earth spike right at the machinery. --as a noob you can remember the T as the spike which gets stuck into ground/earth to make the connection
That 10 mm² requirement was just some intermediate measure to allow TN-C longer in some cases for some reason. Originally it was done with the normal neutral wire. IIRC In Germany the 10 mm² rule was few years in the early seventies. In Finland it was from 1989 to 2007. From 1930 to 1989 TN-C with the neutral was the norm (though a separate ground wire was allowed in 1957). The reason to choose TN-C was originally just to save copper.
It may come from the telegraph/telephone industry. Some circuits were -50V DC single wire systems (typically to save copper cable on overhead wire systems), and therefore used earth for the "return" circuit (with the battery positive terminal being connected to earth). But when multicore cables came into common use, some circuits, instead of using an "earth return", used a separate cable core. To remain compatible with the existing circuits, the battery positive remained connected to earth. Sometimes terms cross from one industry to another...
To create a new "standard" of 230V they widened the tolerance to encompass existing 220V and 240V supplies. Theoretically all new transformers are 230/400V.
I don't need one of these to know that the wiring in my house is horrible. It was built many years ago when they really just didn't bother with earth. So there are no RCDs, fuses are actually proper fuses and no socket has an earth connection. The earth pin is just not connected anywhere (not even to neutral). But since it doesn't gives us any problems nobody really wants to invest the time and money to re-do the installation. When I was converting the attic into a workshop I at least properly wired that - connecting the earth line to neutral (and actually wiring it up in the sockets), added a proper 10mA RCD with a properly rated fuse.
Worked on a huge permanent lighting installation some years ago where the electricians that had installed it swapped the Earth and Neutral on every single fixture plug.
Drove the audio guys nuts trying to figure out where that hum was coming from, since all the audio gear was correctly referenced to Earth.
I have a basic one, because when you're renting it's really handy to be able to look at a property and quickly find out whether the electrics are vaguely trustworthy. Missing earth on GPO is common, but I once found a reversed live and neutral which only became a serious problem when the real estate agent present said "if it was a problem I'm sure the owner would have fixed it"... see ya.
Ouch. (Or possibly AAAAAAAAAAAAAAARGHHHHHHHHH!)
Had an outlet that wasnt working. Maintenance guy held a non-contact voltage detector to the outlet "Nah its live" I left shortly after because maintenance in general was lacking and they wanted to raise rent. AC/heat pump would leak out in 2 months, one sink in the kitchen was missing a P-trap, etc.
You silly people with your keyed sockets where a fixed orientation for live and neutral is even a thing.
Jasper Janssen
Better yet is keyed sockets where live and neutral isn't a thing. ;->
Jim Fortune what, 4 pin 3 phase? That’s the only ones I can think of.
The 2.5 megaohm resistor across the LCD is to clamp any stray voltage across the LCD. They require almost zero current to operate, so almost any stray electrons will get them to activate.
We had a metal sided garage built at our local scout camp. It was in operation for about 10 years when last summer i happened to be in bare feet and leaned against the siding and felt a mild shock! Thought I was imagining things so I had a friend do the same thing with identical result! Turned out to be a combination of two things. When they wired the garage pony panel they brought over the two live wires and neutral but no ground and no one ever put a0 earth ground wire into the panel, as a result the entire building was a floating ground! Combine that with a poorly installed thermostat for electric heat that they managed to install crooked enough so one of the line wires could touch the box side. No earth ground so breaker did not blow but result was that the entire building shell was at 110v with respect to ground and I was the first to discover it after 10 years of use!
bet the scouts $1 each to put their tongues on it lol
and some people ground the rebars when they pour concrete.
a common problem with inverters in vehicles. no real ground !
Yikes. I was noticing some floating grounds all around one building I worked on (US) and decided to do bootleg grounds after a thorough!!!!!! And proper testing of polarity ( I open the main panel verified everything and connected to a known good service outlet that I checked and ran extension cords all around the building and checked every single outlet and switch, thankfully in a small building) as I could see the refrigerator floating at 1-10 voltage and something else metal floating at another. so there is a lot of "main panels" all over this building now but I feel that's safer than having no ground and all exposed metal work that could become live any at different potential. This was an old building where they upgraded the electrical panel when we moved in and then ran the old panel as a subpanel, I suspect most of the wiring is 2 core no ground pretty much everywhere except for in the kitchen And where it was updated? of course, only in accessible places.
Edit, AND DON'T DO IT.
Maybe I should explain for foreigners where ground pins are required because they make so much more sense!
In the US allot of older homes,,,, have 2 prong outlets.
you can use an adapter that plugs in and gets screwed on, however nobody ever screws them on and you never have them when you want them so…. there's a very large tendency to break off the ground pin on a 3 prong device ( computers, audio equipment,,, ) everything if you work or live in a two-pronged outlet building.
options other than breaking the prong off ( Not Code ), is to hire an electrician to replace everything ( Code $$$$$$ ), replace it yourself ( can be Code if correct ) or just change the outlet from a two-pronged to 3 prong and not do anything at all and lie that it's fixed ( Not Code ). install a GFCI in the breaker panel ( if one exists for your old nonstandard panel ) / ALL locations ( Code $$$ ).
or what is called a bootleg ground ( Not Code, as it breaks the one bond rule ) which will pass the house inspectors 3 digit light tester if they don't know any better, it's also good for realtors.
So do you have slightly miss wired outlets or have people going around breaking ground pins and developing a really bad habit?
That's awesome! I assumed the LCD was a joke, but using it like that to detect earthing problems (without requiring a battery) is a brilliant idea
Many years ago when I was at university I built an RCD tester that had a resistor to ground. The room wasn't on an RCD so I told my room mate DO NOT hold the button in. A while later I left the room. On my way back I heard a loud bang and on returning to the room I saw a cloud of smoke and my room mate sitting on the other side of the room, trying to look innocent.
I work on the distribution side in the UK. When I'm doing the cut out change we plug one of these little things in just as a basic test we go for the nearest socket to where I am working. Out of 10 houses 1 will have a a fault on the socket most are cross polarity in the socket.
The LCD warning needs around 3-6VAC across it to operate at 50/60Hz to fully dark, so any voltage over around 50VAC will operate it reliably once you take into consideration the high value series resistors also there. The diodes are there to protect it from high voltage breaking down the thin film of liquid crystal in there.
I have a neon one with a resistor for GFCI testing and button to shunt it. Tiny thing that seems to work really well and impossible to plug in wrong unless you completely disable the safety.
5:10 That function is mandatory in testers in Finland. Old wiring was often done with two wires with earth connected to neutral in the socket. Sometimes when laymen did illegal wiring they actually connected the earth to the line instead. Such connections have caused fatalities, latest in 2015. Also four non-fatal accidents since 2012. In four four the five cases it has been caused by a mirror cabinet in the bathroom. Those are real shock dispensers. I would ban sockets on those or at least allow just euro socket for a tooth brush.
Very useful information and testers. This issue just came up for me with some dodgy building wiring. Thanks!
The beeping at 3:42 played hell with my hearing aid confused the agc I think.
Keep up the good videos.
Our home is on a TNC-S system (as are all the other homes in our area). Mind you we're pretty rural (even by Aussie standards). Always beneficial to ensure the earthing rod's kept "well-watered" for pretty obvious reasons, which can be difficult in our parched environment!
Phil S just put it deep not far away from your septic system?
Just saying, there are "other ways" of providing water + electrolytes to the ground around the rod . . . . . :-)
Isn't TNCS grounded at the distribution station? So you don't need grounding at your house?
Our system was originally TT (local earth only), then a few decades ago we combined local earth with neutral (so an upgrade to TN-C-S). We still have the local earth rod, and I've noted that if we disconnect the rod, earth loop impedance is pretty high, so I keep the rod connected, and "well-watered" as an added safety measure. Useful when the nearest "real" hospital is over 100km away . . . . . . .
Holy jeez. When you went to show the Earth potential test, my heart skipped a couple of beats. I thought you were about to touch live on purpose!
If memory serves the single-segment LCD is a copy of an earlier Beha branded unit which was the first to check polarity, the Germans having decided this was *absolutely necessary.*
The LCD is a reasonable way of indicating a voltage differential using a low current, replacing a neon. It is more visible than a neon in most lighting conditions. Of course once you have a microprocessor in there (like the SOK36) you can use power from the mains to drive an LED without exposing the user to unsafe accessible currents.
Handy tools for quick inspections .the best are the ones with a beeper thar you can hear from far away when you are looking switch the power off
lick the socket...if it tickles then it's live !!! ... electricity comes in many flavors...but it all tastes like "currants" !!!
That must be why I don't like Flies Graveyards, because there are too many Currants in them, and they are too square. They need to loosen up and LIVE it up a bit in life. Ohm My God that was a terrible joke, may I say so myself. Though I like to AMP things up, to create a spark of AMPmosphere in the joint.
There is a condition that can occur when some scroat has been at the copper in the local substation and the Neutral is disconnected from the Earth! The effect is that the Neutral "floats" at a point somewhere between the 3 phases (dependent on the load the houses put on the system)! This gives not only a random Live to Neutral voltage but a voltage can be generated between the earth terminal and the body of earth. Not a usual occurrence but ......
You know its a good Video if it contains "with schematic" in the title
I've had a voltage probe screwdriver (Yato YT-2863) which had "LCD voltmeter" working in an interesting way: There was a resistive voltage divider wired to the LCD connected to the "inductive test" path which lit up sections showing predefinied voltages (12, 36, 55, 110, 220 V). Measuring approx. 220V would light up 12 to 110V and 220V would be very faint. Once I've disassembled it to check how "indictive test" works I could never reassemble it to make it work again :) Now I have an insulated screwdriver. Oh, and "inductive" path looked like it was actually "conductive"...
Clive you misunderstood, it has an "El Seedy" display!
Here's an idea anyone could take; Make a version of this with a multi-coloured LED with individual colour channels (rather than colour triggered by software in a microchip). or individual red, blue and green LEDs. Then when plugged in, "Yellow" could show the "OK" state, while all other colours represent an error state. For the earth leak test like on the generic green model shown, make it light red, and include a piezoelectric buzzer which will only chirp briefly for error states.
In Finland only testers that have a reference to actual ground by touching are allowed. Here many sockets are grounded by connecting neutral to ground on he socket. If one instead accidentally connects the line to the ground a socket tester that just compares the voltages does not detect it. I may show mixed neutral and line but that is not a critical error here.
Seeing the schematic with the neons reminds me of once when I was young (and stupid), I tried connecting a neon lamp directly to mains with no resistor. I'd measured the resistance of the bulb with a meter and it basically read infinite ohms so I thought "well, with a resistance that high it's never going to have much current going through it, so I don't even need to use a resistor". Bad idea! I didn't know about the way the resistance drops quite low when the lap is lit. Got a bit of a bang.
At 4:41 Clive says "I have slight lag on the main RCD to avoid it tripping" can you explain how ? I have the same problem with my workshop. If I accidently cause a trip, the trip in the house that runs the workshop fires and not any of the trips on the workshop consumer unit and it's flippin annoying.
+Joe Farr You get a type S RCD with a slight delay to allow instant RCDs to clear the fault first. On events we use multi-layer RCD protection with programmable RCDs. They're quite expensive though.
I had an old neon Daniel Woodhead tester. The plastic base for the prongs finally degraded and it fell apart. I admit I was surprised how simple it was inside. Anyway, I bought another one.
You can find the common "Cheapie's" most places but building code requires the use of "Arc Fault" breakers to be used through out house now. So as an electrician we have to buy the ones that check correct wiring, GFCI's (wall device or breaker), and Arc Fault (device or breaker), all in one tester.
Arc fault hasn't arrived here yet. That's possibly because with 240V we have less arcing issues and faults tend to be more decisive.
bigclivedotcom they started using them here for fire protection really. Example: lamp on night stand next the bed gets knocked over, when the lamp hits the floor the glass breaks and of course there is a large current draw as the filament burns up due to it being exposed to the O2, their theory is that if the filament doesn't break fast enough it could lay on something like carpet and continue to burn that's where the arc fault kills that circuit as soon as it sees the arch. It all started in California where most of our NEC codes take root.
Big difference with the new lighting. Much better.
I've got an old Briticent Gripper that's great for finding any voltage on the earth, especially if the grounds wet...
Hi Clive, if you keep your finger on the RCD test button, the resistor will not get hot if you are testing a properly functioning RCD.
The RCD will trip and the voltage across the resistor will be switched off.
My reference to dissipation was if the unit was used on a circuit with no RCD, a malfunctioning RCD or one set for a higher current. It's human nature to just keep the button held in when a test fails in the hope it might suddenly work again.
Interesting to hear your weird UK electrical systems.
10:00 had that happen at my house. Could carry arcs off of the stereo, TV, cable, etc. when I touched them.
Can you make a video about why UK and US plugs are polarized? In Germany the plugs aren't polarized and are still perfectly safe. I guess it's because having a fuse in the plug requires polarization?
I'm also not sure, but i think its a safety feature to prevent things like hair dryer elements from going live even when off
It certainly makes Edison screw lamps safer as they can be designed such that live is always recessed into the fitting rather than the screw thread being live. Probably lots of other situations where its safer to have a known live and neutral. There's probably (slightly dodgy) devices out there that have a switch on one wire going into the device, if its polarised then it can be on the live wire and make the device safeish rather than appearing off but still being live inside.
Ross Mitchell, Edison sockets are polarized in Germany (and surroundings). The wires going to the German sockets are also polarised. It's just the sockets themselves that aren't polarised: there's no regulation on which wire should go where, and you can put in a plug both ways. French plugs strangely also have no polarization regulations, but plugs only go in one way there.
I believe that since we all have earthed devices now, it's not so important to polarise the plugs: you can always make a device safe with the earth.
But the US also has two pin plugs, so they are not necessarily polarized.
+whuzzup, Any 2 pin plug that feeds mains into a device will be polarized, at least newer equipment anyway. Things like your phone charger usually aren't polarized though.
BRILLIANT Clive, I was just po9ndering these very items. Thanks so very much matey
Bob
England
I've been watching for awhile now, and this is the first time I have heard you mention (or the first time I understood you to be mentioning?) the different kinds of grounding/earthing that are commonly used. It seems that here in the USA we use the TN-C-S Earthing System? And the chart on the page I am looking at now shows that Great Britain uses TT and TN-C... I never realized that this was so different. I knew that you British called the 'ground' pin 'earth', but I thought that was pretty much the extent of the differences -- other than the voltage difference, and the fact that you guys in Britain use 50 Hz rather than the 60 Hz that we have here in the USA. I know higher voltages can jump farther distances as well, which makes me wonder why Great Britain went for 220V rather than the 110V into the home wiring of every plug in the home? I know the USA would have needed to make a LOT of stuff obsolete overnight to switch to 220V, so it was never going to happen. But it seems like Great Britain was more able to choose between 110-120V or 220-240V standard, and clearly chose the higher. I know we can get to 220V by using both of the phases -- and usually do for things like home electric water heaters and the kitchen electric stove. Most everything else, though, is 110V here in the USA. It seems like all of your 220V electrical components would need to be 2x as 'tough' (robust?) (compared to same component in 110V variant) to withstand twice as much voltage -- either flowing through it, or being held back from flowing, etc. I know that doesn't necessarily translate into 2x the cost, but still. What's the benefit from having everything running at 220-240V rather than half of that? If I were to accidentally grab a hot wire, I damn sure would rather it be 110V @ 60Hz instead of 220V @ 50Hz! Sure, you're 10 cycles less per per second, but that's still 50 cycles that are at 220V!
I don't recall if you ever said this or not. So I will ask. What is the grid power color code in China or is it what ever they happen to grab?
I'm not sure. Bit they certainly use whatever comes to hand in their products.
@@bigclivedotcom Every time I have a failed thing that has the "Made In China" logo on it I expect to someday see bugs crawl out of it.
Are you going to have any planned explosions this summer?
8:12 can we see that demonstrated? I want flames!
Clive, i'm really not sure this new lighting is working. The top half of the video looks rather overexposed, especially the notepad. Maybe its just the exposure on the camera needs to go down a notch. Or maybe the lights are in a slightly different place to the previous ones?
yes it looks also way to red in the histogram imgur.com/a/ULd8E
Must be those new garish red tinted "high CRI" LEDs.
It's not a problem with Clive's lighting, but with the camera/editing software/youtube.
well obviously it doesnt fit very well to his camera setup
+max things
Why would you blame the lights when the camera is not correctly set-up?
I guess it makes sense you get a TT supply in the IoM!
There is a certain irony in the name.
Clive it would be nice if you can do a quick "tutorial" on the different connection systems.
Manick N John Ward has covered it extensively
th-cam.com/video/AWxeb2MI37c/w-d-xo.html
Eliot Mansfield thanks. I will go through that today.
I think you need to set up a 100a breaker outside your rcd protected circuits so you can do lots of dangerous stuff with ease 😁
@ 8:20 Well... 8W in a 2-3W resistor is one thing... Having 240V over a Tact switch is outright bonkers! Aren't those usually rated 50V or so?!?
Won't the vast majority of the voltage be across the resistor rather than the switch? It would form a voltage divider between the resistances of the resistor and the switch.
Motorman2112 once switch is fully closed -yes. Problem starts when the switch is released and there would be sparks. With enough sparks you have ionized air that would attempt to keep a conductive path open. One saving grace is AC voltage the other is a functional RCCB/GFI/RCD. Pushing this button repeatedly in a non-GFI environment might trigger a nice ion channel / little plasma cloud that potentially stays hot enough through 0-volt crossing and burn out the resistor in a spectacular way.
I enjoyed your video, Would you be able to explain the circuit for the loop impedance test on the "socket and see" tester ? Many thanks Marcus
Awesome vid, Really interesting product, the same concept would work on 110V/60 here in the U.S of A.
I have one that I got at Home Depot. Like the green one in the video, it also has the button which shorts to ground so that you can test GFCI. I use it every time I wire a socket, but I originally bought it to help me figure out why stuff plugged into this one outlet would always shock me :)
Here's the one I bought: www.homedepot.com/p/Klein-Tools-GFCI-Receptacle-Tester-RT210/206517824
I'll guess that if the shocking appliance still worked then the ground was missing?
It was a floating ground combined with a misbehaving ballast in a fluorescent lamp on the same circuit. It would come and go as I turned on or off the lamp (but I hadn't made that connection), making it surprise me once in a while.
They also make a much simpler one that is sold at any hardware store in the US. It has three neon lights that light up to tell if you have any of the problems Clive was talking about. It is the classic triangle circuit. I have one and it works well. It was under $10 US, so yes they do make them for the US and you can get one at any hardware store.
I should get one of these testers as I'm sure somewhere along the line, the live and neutral is swapped somewhere as my bedroom lamps when turned off can provide some entertainment with just touching the outer casing of an LED bulb and they glow slightly, and from previous experience, they're only switching the neutral (despite the lamps being wired correctly) which I discovered after getting a shock off one when poking a broken LED filament bulb and managed to trip the power in the house... :P
On the Socket&See and the HandyMan there is a double insulation mark but the earth terminal goes into the housing.
Has far as I know, an earth wire is not allowed on a double insulated apparatus.
The double insulation probably relates to the plastic enclosure. The earth connection is for test function as opposed to functional earthing.
Yes, you're probably right and I don't know the GB regulations. In the Netherlands double insulation means:
No earth wire in the cable and a 2 pole power plug. Even not a 2 wire cable with a eathed power plug because you can get the impression the device is earthed.
btw There is no fuse in the tester you took apart, does that mean the 0.5mm wires are behind a 32 Amp fuse? That could end nasty!
Here neutral and earth are tied together in the panel, but there is also a ground rod driven into the earth that is tied to ground (and neutral.)
The earth thing you talked about where the voltages around the house can get wonky must have been what happend at my folks house. Windstorm knocked a tree down on the line and the power went out. They came and fixed it and after about 2 hours suddenly the lights in half the house got super bright and the other half dimmed superbad, blew up all the TVs and some of the kitchen appliances in one half. The voltage in one half of the house was ~150v and the other half was about 85v (normal 115v supply.)
The power company claimed there was no possible way that it could have been their fault and would not cover any of the destroyed appliances as a result. But the problem mysteriously vanished when they sent some guys out around 1am in the morning to work on the line in the dark.
That almost to a t describes what I've read on the subject
yay always wanted to check what's inside one of these!!! 🙂👍🙏
I'm in the process of building one of these with 7 watt equivalent LED c7? lamps as the indicators, as my neon tester was far too dim out in the brilliant sunlight. I'm also going to include a voltmeter in it, and a test function for the one lamp thats usually not lit I got a double pole switch and it just made sense to add the extra wire. So I will be able to plug this in at an event and leave it plugged in and if it's too bright I'll be able to turn it off and still see the voltmeter kind of like a rack mount power distro would do but a whole lot more useful and portable.
I wouldn't recommend that. The reason Fluke recalled all their units was because the test current meant that if the ground connection was broken in a circuit there was a risk of a high enough current shock on associated metal to cause muscular contraction and stop people letting go.
Oh it's a reply, Oh it's a reply from the master of all things Chinese and electric, Oh wait I think you might have replied to the wrong thing?
Or maybe you're referring to my comment on the other comment / video? for N-G Bonds?
Oh "Why Fluke are recalling their SM100/200/300 plug-in testers."Just happens to be in my recommendations list, I thought I watched it.
although I am still in the design/parts stage and I haven't ( it's getting close ) wired anything up yet, so any input is appreciated. I'm using a panel mount voltage display and my only concern is the current draw of the ground LED and possible tripping of GFCI's, i am planning to test that yet and might need to current limit. its a pretty simple design without my complications, it's more or less the triangle with an on-off-(ON) switch on the hot that will toggle between hot on/off and test of ground by swapping the ground lamp from ground to hot.
some more parts came in earlier this week so it was kind of fitting for me to see that there is a video on the subject recently posted.
I have drawn out my schematic coming up on almost a year a go now.
I have most of my parts except for the light bulbs and a clear/transparent case.
Which I decided to complicate my connections by adding in a IEC C14 connector and a circuit breaker for the pass-through IEC C13 and NEMA 5-15 output connectors.
for some reason I like things with pass-through plugs.
www.dropbox.com/s/l3lu0yfwjs93ufi/2019-03-20%2001.54.59%20BCV.jpg?dl=0
How does the neon across the hot and ground not trip an gfi? It has to pass current in order to light... is that current just not high enough?
+Jack Duno It's a very small current. Much lower than an RCD trips at.
Eight Watts Hot. Love it.
Clive can you some day go into detail how the US power systems differ from the UK?
For us if I want 240 I have to use L1 and L2. For you is it just L1 ?
Like I said can you please do a video on this?
Thanks
Thank You both for the details.
I would really like it if Clive could do a video on how they do differ.
He has a way of presenting things so that they are easy to understand.
My 3Ph understanding ends at if the motor is running the wrong way
just swap any 2 legs and your going the other way. I don't know anything
about the feeds from the street out to the sub-station. Neutral does come
in from the street along with L1 & L2. The stuff like stove, electric water heater
and the electric dryer tend to be 240v and any heavy use shop type things
may also be 240v L1 + L2. But really I know just enough to be dangerous.
In my house only live ant neutral come in and the neutral rail is conected to the ground which is just a screw into the foundadion of the house. They call it a Pe-N type circuit here in sweden. I found that pretty strange but aparently it was conmmon at the time when my house was built since very few appliances were required to have earth at all other than wet spaces.
rimmersbryggeri This is the normal type! Never the power company sent "saved earth" to a house from outside. Normally after the Wattmeter the N change to N and SE. Then main switch, RCD, ...
I dont think it is the normal way in sweden anymore but my house is so old it had no earth before I put it in other than for kitchen fittings and the light in the bathroom I think. I think now there will be a separate earth rail in the consumer unit and RCD/GFI is mantatory.
I've also tested socket tester on my small channel, but a different one.
13:27 I think it is useful and one could even hack it together quickly by himself I think.
Have Poundland stopped selling the 1A USB phone chargers? Icoudn't find and and the staff said that they have stopped doing them? Anyone recommend an alternative? My Son in law looses them every other week, t/hey were a nice safe cheap replacement.
They still have them here.
So that explains why the house I worked on a few months ago (not on the electrics, but floor screed) was a shocking experience. Every (steel) window frame, every decorative rock/boulder, even the walls gave people a good jolt if we were either walking around in our socks (to protect the new wooden floor) and touching a surface while grounded in some other way, maybe one hand on a water pipe or something... Bloody electrician....
Those mystery diodes - are they acting as a Diack, with a breakdown voltage of typically about 30 V?
*Diac. (Struck by spell-checker.)
Not sure what diodes they are. The text was obscured and they didn't start conducting when I tested up to about 27V.
The diodes in series with the LEDs won't protect them from reverse bias because the reverse voltage will be across both the LED and the diode, and the LED can't tolerate a significant reverse voltage. The correct design is to put reversed diodes across the LEDs
The older gallium arsenide LED technology is resilient to high reverse voltage. It's not uncommon for cheap indicators to use a simple resistor and LED.
Why doesn't the current from live to earth in the tester trigger an RCD in, say, the mains junction box?
Slight time delay and higher current setting to allow local tripping.
(In an ordinary home with normal 30mA RCDs in the DB it would trip them.)
Thanks Clive.
I think my neon mains tester is even simpler than yours. Only one neon and resistor inside a knob that turns and selects N-L, L-E, E-N in turn. Using it here in France via a travel adaptor caused confusion until I realised that those adaptors reversed N and L. Doh!
This might be useful like here in Italy, where the plugs are not polarized, so you can check which one is the neutral
Clive, the new lighting looks really vibrant but slightly over-exposed. Also, will you ever do a video on how you reverse-engineer circuits? Cheers!
I'm getting used to it. The next video will look softer and warmer.
I love how it has a max voltage of 230... Most mains is now around 240-250 volts. The days of 220-230 are over. Same thing in North America, everything that was 110-115 is now 120-125.
In the US, it was ALWAYS 120/240. 110 is the _minimum_ acceptable voltage, and 120 is nominal, with the voltage usually ending up around 118 volts. So, people saying 110 are actually only talking about the lowest acceptable voltage to drive whatever your device may be. (Or just don't know anything about what they're discussing) As for Europe? No idea. It's been long enough since I researched it that I'm certain the EU has invented new standards because they can't stand leaving anything alone.
Troy Belding nope. It actually was 110 in the early days of AC power. It later went to 115, then 117, and finally, 120. The allowed tolerance is +/- 5%, so the minimum is 114 and the maximum is 127. Typically, unless you're way out in the boonies somewhere, you'll find that the no-load voltage is about 122v, which allows for voltage drop from high current appliances or long runs of wire between the breaker box and a distant outlet.
Be glad we're not in Japan. They have 100v nominal, but in the northern half of the country is supplied at 50 Hz, while the southern half is supplied at 60 Hz. Which means that if you move between regions, you have to replace any appliances that are frequency sensitive.
Yes and no. The early days of AC power varied depending on the region. Chicago would have one, Boston another, and eventually the smaller regions sort of gave in to the larger regions. By 1963, device voltage was 115. in 1984, _distribution_ voltage was set to 120. Some sources talk about Edison using 110 distribution for 100 volts for his bulbs, but that has to have been come up with by someone who didn't understand that Edison hated AC. AC current was _Tesla_. Edison thought everything should be run on DC current. So, basically, 120 has likely been the 'true' distribution voltage since the 30's, and they just nailed it down in the 80's. In Houston, the 'no load' voltage floats right at about 118-119, in most areas. When I see 112, I start being concerned, and the few times I've seen 108 and similar, I had the customer call in an electrician. (That was when one person killed three computers with her under-desk heater)
Panels in the us/canada are 120/240, but receptacles are 125/250.... the voltage is usually closer to 125/250. depends on how many transformers are providing power along the lines to the houses on the block. A lot of new construction has several smaller transformers installed in closer intervals linked in parallel to share loads more evenly. In the past there would be a few large transformers spaced farther apart and if the load would be high customers farthest from the source could experience significant voltage drop, I have seen 105/210 with the A/C and stove on, It was a 200 amp service drawing only 82 amps..... to much distance from the transformer to the house and to many houses on the same transformer.... the lights in that whole area flicker like Christmas tree lights
Peter Dudas I live in germany and I have 229v.
I don't think it would detect a missing earth with the diodes oriented that way. Maybe you could test that?
hi clive what about a pme instalation
Oh Clive please press that RCD button for a prolonged period.
It would only heat up if his RCD doesn't work.
Here in Poland, most sockets are Type E, with sockets for live and neutral, and an off-center pin for ground. Double sockets have both ground pins toward the center of the socket, and so you have to invert one of the plugs to insert it. This inverts the live and neutral. Shouldn't this cause polarity problems?
+Jim Fortune That would only affect things like fusing and switching in the appliance, but it would still work.
When are you going to knock all the power put in ypur area Clive?
at last a good use for death plug adapter
Hi bigclivedotcom, how about making a video about these "arc fault circuit interrupters", aka AFCIs? They are becoming "fasionable" these days, at least where I live and legislators are already considering making them compulsory in certain situations. I really liked your videos on RCDs, so I think doing an AFCI teardown and explaining its function and principle would greatly appreciated!
+Jan H I've not come across one here yet. In the UK the faults are are a bit more decisive at 240V.
Thanks for your reaction! I'm from the Czech republic and we are using 230V (though in reality the voltage is often about 240V). Though I've heard that with the "ring main" you use the UK, less arcing faults tend to happen, because there are two paths and the electricity will use the more solid one instead of arcing... So maybe that's why they would be less useful in the UK...? Not sure.
I've learned about AFCIs from local Czech electrician forum recently and I can't decide if they are overrated or not. My impression so far is that they are a hype and it's mostly ABB and other big manufacturers pushing for AFCIs to be required by the law, in all households.
I'm really confused, because while the idea seems legit, I suppose many devices like motors with brushes make tons of arcing in a controlled manner and are absolutely safe. But if the same arc was happening "in the wild", it could easily melt something or set it on fire. So either a lot of nuisance tripping or not much real protection at all. But maybe I'm missing something.
That's why I thought it would be really great to hear what someone as experienced as you thinks about them :).
Anyway, keep up the good work!
you know Michael Faraday’s magnetic induction experiment where electricity is generated by placing a bar magnet in a coil of copper wire. what happens if two diodes were placed in the wire to block the electricity from escaping in either direction? 🤔
i suppose that the circuit wouldn’t work but magnetism might allow current to flow because it’s a magnetic field 🤷♂️
+Donald Sleightholme It would act like a break in the wire unless the voltage induced across the diodes exceeded their breakdown voltage.
Getting "earth leakage" mixed up with "RCD" and ending up with "arse leakage".
Also, the power rating on the trip-testing resistor probably doesn't matter much. Since if your mains supply is any good, pressing the button instantly cuts the power anyway.
greenaum I I were to plug that In some instalation I know that thing would burst into flames before triping the rcd ( and yeah there is an rcd...
How much and where did you get the pro tester please Clive?
It's a common item sold on eBay, amazon and most electrical and electronic retailers.
Looks almost like Benning SDT1, same OEM maybe?
Finally a legit use for a death-daptor
Are the diodes from earth to live the right way around on that schematic?
Mk3 Dave AC not DC
Love The Clive!
what would the circuit be in a very expensive model, please could you do a video on that
Capt. Marco Hawk same has this one just betters parts
Yes, I'd like to know how they measure loop resistance. My guess is that they put a pulsed load between live and neutral and measure the voltage drop, which is not a trivial circuit.
What's a TT electrical system?
Wonder what that missing R6 would be for ...
My house's ground isn't hooked up anywhere. It freaks me out. Anything I should look out for?
Simão Rodrigues Electric shocks...
Some countries use ground and some don't.
How would someone test if a damaged wire was putting current to ground inside a grounded steel conduit?
An insulation test between the associated wires and the conduit metal. Normally a high voltage tester would be used for an accurate result.
When current flows from Live to Earth, through the Neon, why doesn't that trip the RCD?
+billymonkey111 It's less than 1 milliamp.
Is that rectifier diode 1n4007 or similar?
+Lukas Liwandouw It would be a good choice.
Dear Clive, after watching your very useful video, I decided to buy a socket tester. I looked on Amazon. They have two types made by Socket and See: the SOK36 Professional is £51.95, the SOK22 Craftsman is £19.96. Would you recommend one of these -- or another brand? Best wishes, John in the Peak District.
If you just need a basic tester then a cheap simple one will do. If you are working in an environment where the loop impedance test is needed then that's a good option. For personal home use I'd suggest something simple like the simple three LED and test button type. For professional use the one that does the loop impedance test is useful for a quick test. It's worth noting that the electrical distribution industry issues the loop testing one to their meter installers to use as a quick check.
Live is called Active aswell.
Yesterday I opened the Amazon Basics calculator I have to see if the PV cell on the front was real or if it's a fake cell. It's a real PV cell! It's wired to the circuit board and when I pulled the silver oxide button cell out of the holder, the PV cell (with enough light) powers the calculator! I expected the PV cell to be faked (I think Dave Jones also did a video on this.)
the funniest fake solar calculator i have is one that has a see through case. You can literally see that the solar panel is fake while its still inside its packaging. Bought it though because it was like 1€.
Well, i think its real but not even any wires attached to it.
The most fun you can have with a PV calculator is to remove the battery and interrupt the light to corrupt the memory.
The solar panel is connected to the battery via a germanium diode ( yes Ge diode, not Shottky) and there is a red led across the battery in case the cell is removed, though some models use a little blob containing 4 silicon diodes in series instead to give a 2V voltage clamp. The solar panel in any case can only deliver under 1mA in bright sunlight, so the tiny alkaline cell in there ( generally a LR44 or other small button primary cell) will never be overcharged, unless you leave it outdoors in full sun for a month, which will melt the case anyway. Indoors the panel only provides a tiny top up to the cell, and in any case those calculator chip run on a LR44 for about the shelf life of the cell anyway. Those with a single AA cell in them I generally use a cell that will not run a clock, and in the calculator it runs fine for years.
I have a Casio from the 80s with a PV panel and it's still working now on the internal battery after all these years without a replacement.
Incidentally the two diodes save the lcd by handing the voltage off to the user, cute feature
Hi! Which kind of diodes are these? Thanks
Standard 1A diodes like 1N4007.
@@bigclivedotcom Thank you for taking the time to answer. That's very kind of you
TT electric, is it only available on the IOM Lmao.
LCD Display... isn't that a bit double, Clive?
That LCD looks re-usable for other applications. The RCD test gave me an evil idea to build a microcontroller based "random power disconnector" that would trip the RCD randomly :>
pure evil haha
Unrelated, but... I have a Yihua 937D+ Soldering Station, the middle digit on the display is screwed up, the iron seems to heat up and work though - the seller gave me a 70% refund...
Just wondered if you had any ideas, - I had look and can't see anything obviously faulty, or dry connections etc...
Does it light or display what looks like all the other digits combined or a combination of two. It sounds like a solder bridge defeating the multiplexing.
I thought that, as the left and right digits work fine, the middle one displays random segments, some brighter than others...
I have some pics (and a small video) if you got an email address and/or forum :)
Great lighting
You said your main RCD is setup to "lag." How did you do this?
John Hollowell digital GFCI?
+John Hollowell You can get programmable units or a type S RCD that is designed to offer a 100mA/100mS trip characteristic.
In germany for the TNC (C=common neutral+earth line) system gnd/earth has to be 10mm² until its seperated into Neutral+Earth = TNCS (or then TNS, s meaning separate),
so you cant really say its cheap to keep it that way.. and you really have to try hard to brake the 10mm² common neutral+earth connection ;-)
The T-T (earth at incoming point, earth at machinery)System most of the time is only used in industrial applications where you set your ground/earth spike right at the machinery.
--as a noob you can remember the T as the spike which gets stuck into ground/earth to make the connection
That 10 mm² requirement was just some intermediate measure to allow TN-C longer in some cases for some reason. Originally it was done with the normal neutral wire. IIRC In Germany the 10 mm² rule was few years in the early seventies. In Finland it was from 1989 to 2007. From 1930 to 1989 TN-C with the neutral was the norm (though a separate ground wire was allowed in 1957). The reason to choose TN-C was originally just to save copper.
Where do they call neutral “return”, never heard that.
It may come from the telegraph/telephone industry. Some circuits were -50V DC single wire systems (typically to save copper cable on overhead wire systems), and therefore used earth for the "return" circuit (with the battery positive terminal being connected to earth). But when multicore cables came into common use, some circuits, instead of using an "earth return", used a separate cable core. To remain compatible with the existing circuits, the battery positive remained connected to earth.
Sometimes terms cross from one industry to another...
I thought that UK volts used to be 240v and europe 220v but now all standardised to 230v not checked it though
To create a new "standard" of 230V they widened the tolerance to encompass existing 220V and 240V supplies. Theoretically all new transformers are 230/400V.
I don't need one of these to know that the wiring in my house is horrible. It was built many years ago when they really just didn't bother with earth. So there are no RCDs, fuses are actually proper fuses and no socket has an earth connection. The earth pin is just not connected anywhere (not even to neutral). But since it doesn't gives us any problems nobody really wants to invest the time and money to re-do the installation. When I was converting the attic into a workshop I at least properly wired that - connecting the earth line to neutral (and actually wiring it up in the sockets), added a proper 10mA RCD with a properly rated fuse.