WALK IN FREEZER NOT COOLING
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- เผยแพร่เมื่อ 23 ส.ค. 2024
- Well this was a first!
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The electrician was hoping it was just the breaker lol
They work by a process of hassle elimination.
You just found out why many automotive techs use test lights and not their fancy meters. A test light will draw enough current to prove there's really a connection. A meter is so high impedance, it can see phantom voltages. For example: at 1:45, you saw a dead leg. But once you opened the disconnect, you removed all load from the power line and saw strange leg-to-leg voltage. Same with the ground line. Just stretch a wire along side a power line and measure it's voltage. Your meter will see a voltage - but any attempts to use it will show that in practical terms - it's not there. The breaker never tripped as there wasn't any solid short. The wire just corroded "in place" without shorting.
Breaker did not trip because the resistance was high enough to keep the current low enough. A multimeter measuring voltage has a pretty high resistance, and you still got effectively 80 volts out of 120 over the meter, meaning the meter had twice the resistance that the broken wire through that fluid had to ground.
Some googling suggests a voltmeter in the 250V range has a resistance of around 2.5 MOhms, so that broken wire shorted to ground with effectively a 1.25 MOhm resistor inbetween. That will not draw enough current to trip a breaker.
They are however lucky to not have had a lightning strike through that broken wireset...
Agree.
But for the weird voltages I think the explanation is that the broken wires next to good wires acted like capacitors. About 2 nanofarads will have an impedance of 1.25 MOhm at 60Hz. First random search results indicates that about 100ft of Romex (which this isn't, but using as an example) has about that capacitance, which seems reasonable for the results in the video.
This is a case where a "test light" of sorts (for example a 10k resistor that won't over heat if fed 240V) would come in handy. Connect that and measure current and voltage and you would likely see single digit volts or even lower, and single digit milliamperes or less.
@@Thesecret101-te1lm yeah, it was more induction than anything. a LoZ (low impedance) capable meter or add-on would have pulled it way down and shown the issue faster.
Voltage on the ground was enough for me simply because the cable was underground, did wonder why it didn't trip though, do they fit breakers that would have?
Edit, I'm in the UK, our regs may be different.
My dad's house was poorly built. The company that built the house years ago (they are no longer in business) cut many corners. They put emt conduit in the cement foundation. The conduit sank to the bottom as the cement was solidifying. Over many years, the conduit had rusted, broke, and filled with water. I had the same issue pulling wires. Most of the wires were very difficult to pull. They were covered in rust, dirt, and water. The final conduit that ran to the circuit breaker was collapsed and the wires were permanently stuck. I ended up running new conduit through the attic to the circuit breaker panel. My guess is that the wires and conduit rusted and broke apart. Most likely the rust and corrosion was providing enough resistance to prevent a short.
Man that labor bill alone would be high as hell
Recently discovered your videos as I’ve developed an interest in hvacr now that I’m 100% sober
Im addicted
🤣🤣🤣😂😂😂
@@Android_WarriorHey, addiction is no laughing matter. It takes a lot of willpower to quit drugs and/or alcohol.
Even if he's now addicted to Chris
@@thomasvlaskampiii6850 : And where is alcohol mention here or other specific addiction???
@@Android_Warrior It wasn't. And alcohol is addictive. People like the feeling of being drunk. It eases their pain, if only for a moment
Hey, I love your content. It’s very educational for someone that does not know anything about HVAC systems. So thank you and I’ve always by the way how to dream of being on TH-cam and I’m now having that dream got 216 subscribers. Please keep up the amazing work.
Thanks so much bud and congrats on the 216 subscribers !!! Keep it up!
My theory is that the galvanized conduit wore through its protective layer and began rusting out under ground. This, coupled with settling as the building aged, eventually severed the conduit, which then began cutting through the wires with vibration. Eventually they cut through, probably the ground first, and then the power wires. The shorts occur on the system-side of the fracture, which is how you are getting all these weird voltages and the short to ground and conduit outside, but due to the broken connections there's no short back to the panel. It is possible that the breaker may still be faulty since it did not trip, but I guess if the wires blew apart fast enough, the breaker would have escaped popping. The only confusing part is that, you clearly have at least some 208 phases outside, yet the wires are severed. So you are gaining a phase from somewhere without the breaker nuking itself.
Water soaked.
Even with protective layer, metal conduit is too soft for sub surface installation and will squish easily, for instance from a rock. There is also a possibility it separated between sections which made for a sharp surface that will cut into insulation. That given, installation can also be overloaded in too small conduit and overheat and break down insulation layer or degrade it over time. Wires can in some instances, if sections are dry, work with completely melted insulation for years as long as they don't short - for instance, they get moved during renovation.
My thoughts exactly. I had this happen in a school on a 480v circuit. Ran new lines overhead through ceiling. While pulling out old lines from underground, nothing but wet, rusty, corroded wires coming out. The maintenance guy and I walked a couple hallways and saw cracks on the floor between switch and outlet boxes. I warned them, this would happen again and to plan ahead.
What I think happened is that one phase and the ground were broken and they had a resistant connection through water or silt, so there were no dead shorts in that case, and that would be why the breaker didn't trip. I may be wrong but it's an educated guess, it would also explain the corrosion because electrolysis would be happening between the broken pieces. Either way very dangerous situation with wild voltage; glad you got it solved with a new run!
Keep on what you are doing..... after many years for you are the only HVACR that I have intrest in.... how you go thru your things in the videos an your aftermath love it...... keep this videos flow as you have be doing thru the years.... thank you wery much
I really like how you said thats eriee when you said 'i dont hear the clndenser running' that plastic bag could have been possibly stopping the fan from running causing it to trip the high pressure. Thats crazy one leg of power was not going to the ground! Whats mind blowing is that when you touched the building you got 82 voltts thats enough to shock someone they really need to check those breakers to make sure their ok! Stay safe chris Love ur videos!
Threephase motors can run on two phases just fine, sometimes for months without noticing. All you'll hear is a louder growl. They overheat since only one of the windings does all the work. (technically speaking, remaining two are slightly active as well). Such a motor will generate a third phase by itself, allowing it to power the fans, lights etc. small loads, albeit at a reduced voltage. 82V on case is high enough to be deadly with direct contact.
I love the electrical problem's as a viewer but i know it's thug to deal with this type of problems. I like the way you explain, even though I have no knowledge of the subject, I managed to learn something from the information you provided. Best regard from Romania
Good catch on that energized cabinet! I knew somewhere it was corroded badly with the huge difference on that one leg. Definitely not the way you want to spend a Sunday
Ground has power on it, water soaked conduit.
I have been watching your channel since 2021. HVACR/Survival since about early 2022. You both have your own unique styles to your videos. I never miss a video from either one of you. I can't thank you both enough for what you do!! Obviously nobody is perfect. But you and Rick are tremendous assets to the hvacr trade! My apologies if I got a little too fanboy here. I just felt you deserve to know how much you're appreciated. ✌🏻✌🏻
Thanks for the nice words bud!! Also Rick is a good friend of mine and I agree he is a great tech!
That was an interesting one for sure. Thanks for another great video Chris! 👍🏻
I finally received my pump from ttt. I was able to use your offer code. Great video!
Right on man!! Thanks for supporting the channel by using my offer code!
capacitive coupling from the wires being next to each other and no load
Buenas noches estimado Chris, un trabajo difícil de diagnosticar y complicado en reparar. Pero tú te las sabes de todas, estupendo diagnóstico y reparación.
Saludos desde Coacalco Edo de México.
A coworker once told me a story. They ran a wire and someone hammered a nail close to it into the wall. Not damaging the cable. 30 years later the breaker tripped suddenly. 30 years of tiny movement made the nail dig into the cable
That's pretty neat
Buenas tardes Chris, como siempre resolviendo los errores de los demás y me agrada mucho la manera en tú reacción tú hablas constructivamente ya depende de cada quien cómo reaccione. Gracias por todo Chris.
Saludos desde Coacalco Edo de México.
That was insane! Electrical problems can definitely cause head scratches!
Thanks for your Consistent and Strong 💪 Efforts. 👍🙏
Top notch as always Chris. Always look forward to your videos. Stay cool out there.
That's wild
Yeah it was a fun one to say the least
My guess is the galvanized conduit rusted apart, shifted and cut the wires allowing the wires to degrade. I work in a concrete batch plant and have had the joy of fixing old conduit
Doctor, I concur with your diagnosis 😅
On month 7 of my service career, why did i do this to myself 😂
All I can say is, your glove habit was a VERY good thing in these wire-hunting shenanigans. If ground is LIFTING on that box, touching the box and anything else would HURT.
Personally, I like the way your do your videos. In this instance calling in an electrician was the right thing to do. This was a very mysterious problem and as the saying goes "two heads are better than one".
I still prefer, none of us are as dumb as all of us 🤣
Nice @ 1:06 AM I'm watching this and You Yawned great timing Chris!
Haha
Yoooo when the OG Sporlan promo hit I was like awwww yeahhh
After all the utilities and plumbing/hvac videos i have watched on youtube, i don't put anything past anyone taking shortcuts or "forgetting" that something happened. Bet you a million bucks that the galvanized conduit is corroded away under there & a stone from the construction backfill or some concrete settled in where the conduit was, causing damage to the wires & leading to all that copper corrosion.
Just chased down some gremlins on some old aluminum morris connectors wrapped in tape for decades. We had weird intermittent voltages with the meter. If you loaded the circuit it would drop to 2 volts. We cut the tape off the connectors, they were so corroded, it looked more like white chalk and rocks inside instead of aluminum. It worked perfectly until it couldn’t anymore. 20 - 30 amps going through a tiny sliver of good copper on a #6. But it was up in the air, no way to know it was getting hot without getting a lift or ladder and going up there. IMO - you did right.
Aluminium connections will do that. Wires should be cleaned, screwed into terminals and special dielectric grease has to be applied to prevent aluminium from oxidising again. Chalky is aluminum oxide. Copper wires should be connected with (coated) copper or brass terminals and periodically retightened. Alu ones have special terminals that have to be rated for alu use and you can't mix both types in one terminal due to galvanic corrosion. A lot of house fires due to that.
I've had this problem in the past with outdoor lights in a parking lot the conduit that's run underground steel conduit as we generally don't run that anymore unfortunately can break due to shift in soil and degrade from being in the ground to where you wind up with water infiltration and then corrosion which eventually eats at the wire now the reason you were getting power on that ground leg up on the roof was because one it was broken and there was power leakage coming from one of the phase wires going through the water so you're in a sense we're testing the power at the water the reason you didn't have power at the panel was because you were still connected to the grounding bar if you disconnected the ground wire from the grounding bar and then tested it you would have seen power on that wire as well but because it's not a direct to ground short it's going through the water that's why the breaker also didn't trip best case to do is just pull a whole new run of wire like you did
With power issues like that, you need a proper "Megger" electrical installation tester that can also test loop resistance and not just do insulation tests (although an insulation test would be good in this case).
You could also use a current clamp and check if there's power flowing with everything disconnected that's low enough not to trip that breaker (like if the conduit got water in it and the insulation of the wires got weakened and corroded somehow, which would also make sense when you measured voltage between the ground wire and the case of that AC there).
Edit: Haha...I wrote that comment before watching the whole video and it actually was a corroded wire with water in there 😂
For instances like this here with "using temporary power from some other circuit", you can get current sense relays that can (de)activate contactors and thus prevent an overload on your power circuit. The way you did it in the video is fine too though, as long as a temporary solution doesn't become a permanent one (for example if the customer had declined to have the electrician pull a new feed).
You can have a "ground out situation" that doesn't trip a fuse. Imagine it like having a light bulb connected from one phase to ground with the light bulb being your corroded wires.
An RCD would catch a failure like this and trip, but a 30A breaker won't trip if there isn't a good enough path to ground for enough current to flow (depending on the tripping characteristics of a breaker, you can sometimes have a "short term" trip curve that requires 5-10 times the rated current for it to trip safely. The 30A rating is mainly the "long term" trip current, so if you run 35A through a 30A breaker it will trip after like 30minutes to a couple of hours, again depending on the tripping characteristics (which also change if the breaker gets heated up in other ways, like being exposed to the sun).
Maybe you can ask BigClive to explain it to you too, he is way better than me in explaining electrical things :D
@@nerdywolfi Megger would show insulation fault if the wiring had degraded insulation or was shorted somewhere. Sometimes, a short gets blown appart, breakdown heated so much water evaporates and it will test out fine when you get to it. You also can't test if there's a break in the line which you have to pay attention to. You don't need special devices to check continuity as the load will do that check for you and sag or rise unconnected terminal, but you could check line resistance to provide accurate answer. Sometimes, breakers trip/melt internally and look fine on outside. It's really guesswork working after someone else, learning what corners they cu.
Ground faults via loads are known to exist, like for your example, a light bulb shorting neutral to ground. Such instances never trip the breaker but may trip sensitive enough RCD if the device current is high enough. You are correct about not tripping a 30A breaker. Such breakers trip at 100-200A instantly (magnetic trip) and can sustain at least 50A for few seconds until they trip thermally (bimetalic trip). Large breakers often provide no protection with partial breakdowns and will blow out the short rather than trip. 30A breaker will sustain 32A+ or more permanently, depending on environmental conditions, state of equipment, type of load and temperature in box. RCD's aren't "reliable" for a lot of cases as they will turn entire fusebox off and will just get reset at infinitum without understanding conditions why it tripped. There are devices that detect arc faults, ground faults etc. and need to be installed at transformer stations as the reaction time of main fuses is too high and will damage equipment. They can detect issues in single period and cut the power within 1s.
Love seeing you running into Head scratchers and learning from you Sir
You can use a LOWZ meter in these situations. It has low resistance and will pull thet phantom voltage down.
with a ground wire that is connected to "earth" you can get less then 10amps flowing (@120v) from a hot leg to a ground wire that goes into the ground.. Not enough to trip a breaker but I bet the conduit was toasty hot underground. If it was shorted to neutral it would have popped immediately. But earth ground is a high resistance return which limits the current. The ground wire from the panel was probably not touching anything at the break underground and the short was from one leg to the conduit and the piece of broken ground wire going to the AC.
In Texas we can't even legally change a disconnect box much less pull wire from a box to the disconnect. We are "supposed" to have an electrician come change out the disconnect. HVAC contractors can only run the wire from the disconnect to the equipment here.
Similar to where I am in Canada. I have certain wiring I can do in residential panels for new a/c's, but, generally, I cannot go past the disconnect/switch legally. Definitely not allowed to remove any 3 phase breaker covers.
Just a big underground water boiler 😁
Mysterious voltages on broken/floating wires are often due to capacitative coupling between the wires. You can use a Lo-Z voltmeter to test this theory. On the other hand, I would have expected the broken wires to short to ground via the conduit and trip the breaker.
That was a very interesting one! I think you would have been shure if the wires were broken by checking continuity between the breaker box and the disconnect switch. Keep up your good work!
Great vid as always! PS. That definitely was the right thing to do to get the electrician involved. That was a total mess that no HVAC guy should tackle alone. Again great job.
Thanks
per NEC all conduit is considered a wet location and always needs wiring rated for wet location.
in my experience, the majority of all underground, outdoors or passing into unconditioned space, always has water inside, even when sealed from direct water entry, it forms condensation from air leakage and temperature difference. 😁
*edit* I should add, about it being "galvanized", it's likely rigid conduit since it's under or in the concrete of a commercial location(maybe parking lot?), likely only rigid is/was allowed without being burried really deep and having protection. there's lots of NEC coverage on it, I wont even try to get into all that here.
I've seen air draft thru the conduit, condensing inside and dripping out of wall. It was puzzling at first as there were no leaks on roof.
Seal the conduit to keep the warm air and the cool air inside to prevent condensation
If one of the phases and the ground wire were both broken it would make sense in that capacitive coupling would create phantom voltages. These phantom voltages would be read by your meter as digital multimeters high impedance measuring instruments. The phantom voltage would likely just disappear if grounded and not trip any breakers.
One test you could have done would be to connect the ground wire directly to another grounded object and use your current clamp to see what, if any, current actually flowed. Depending on the length of cable run and induced voltage would actually provide negligible current flow, whereas a true leakage current would result in visible current flow. Another test would be to use the phase rotation capability of the meter to try and identify which phase was leaking the voltage. It would probably take a three-phase meter to test further and narrow it down.
Probably water was conducting some power between Phase A & Ground, the water would heat up, dry off and remain slightly conductive. just not enough amperage to overamp the breaker
Not sure if anyone has answered this yet, regarding shared grounds for multiple equipment. Per NEC (used by CA for with exemptions), you need a separate equipment ground for each branch circuit: however if the branch circuits share a raceway/conduit and the ground is sized properly by code, I do believe a single ground would be acceptable. I'm not an electrical engineer, just a designer, so please take what I say with a grain of salt, as inspectors and examiners may interpret code differently.
Hi Chris. Been loving your channel for years now. You taught me a lot of HVAC and refrigeration while I was driving to (hot side) jobs when my company didn’t the resources to do so. Thanks for everything.
Question: Wouldn’t a Lo Z (c’mon FieldPiece, what’s the problem here?) meter function have revealed what was going on? I think you just had some induced voltage on L1, right?
That's a good question, I will discuss this idea more on my next live stream Monday at 5pm Pacific time
A big day for you but a big video for us ❤!
Very interesting. Keep it up!
Btw I recently got my HVCR hat.
Hi Chris
Thanks for the video
Realty u gonna get called like this one
Very interesting one for sure
Great video. Thank you for sharing.
Could have check to see if there was seepage going to the conduit, majority of the time It would have equal a dead short, but electricity does wierd stuff oh you did it!
Had it happen to me, remember ground dissipates electricity till it is absorbed slowly,
I'd love to have someone with a fiber optic camera scope out that conduit. Kinda like Mr rooter does for drain lines😊
I don't know the age of things, but even as just a DIY dude in the comments, I noticed the original electrical was shady with the wrong size grounding. It was good to see the new electrician did a good job and was happy to do less work so Chris could do his checks on the equipment side of things.
God bless you brother
As an Electrician, 80 Volts on the Ground wire suggests to me that you have a leak in one of the Line wires...it's not a dead short yet, but you likely have either a crack/split in the insulation (at a bend in the wire perhaps) or one of the wires is rubbing out and the insulation is now thin enough to allow voltage to bleed through to the conduit but not enough to trip the breaker...
The wires in the conduit from the breaker to the disconnect need to be replaced...honestly, they needed replacing anyway because they're not long enough to leave the slack in the box required by the NEC...
Not being an American Electrician, I'm not familiar enough with California and US Federal Laws to know if you can pull the new wires or a Licensed Electrician has to do it...I don't know if that would require a Permit or not (since it's going into the Distribution Panel, it probably does)...
54 on ground is half of voltage so it easy to understand that wire is not grounded.
Try some example 3 wires some length(5meters+ may be 10+) needed 1 empty(no connection isolated) 1 phase and 1 ground. Try measure voltages you will get half voltage of phase between ground and empty but very low amperage. Some times when switch is breaking ground instead of live led light will glow very very little or flashes when capacitor will charge. Some tips when something wrong.
Ground shifts over time and can have enough force to pull wires out of equipment. This event here may have been bad installation in first place or it got pinched by road works or some other construction. Not every insulation fault will trip a breaker but megger test in here would probably show the fault. Equipment was probably being partially grounded by copper lineset to internal box. Pretty dangerous situation on both ends. That being said: It was mentioned during our training to never touch energised faulty equipment, especially motors that can fail partially while still running. There's less than a mm of insulation on the winding that separates bare wire from metal stator or case. Burned up motors will conduct randomly, carbonized insulation will conduct current. Sometimes rotors with failed bearings will touch the windings as they get out of aligment and get energised too. The white stuff outside on contactors is Cadmium (Toxic) and Silver oxide from contactor buttons. Some contacts today get replaced by tin-silver mix which performs worse. Should never touch or breathe it and wash hands after coming into contact.
I love this video
Great video! Nice meeting you at rsd the other day.
What would have been interesting to do would have been to measure amps from in the main breaker panel to each of the phase wires when you had it turned off at the outside disconnect. I bet you would have seen some current flowing to a corroded conduit or whatever between the two. That might have said a whole lot about why you had the strange voltage on that ground wire, etc.
finally a dad-hat!!! lovely!
well…no shipping to europe, sad :)
They used to use galvanized conduit in the ground a lot back in the 80s and early 90s now we use PVC but even with PVC joints will never be 100% And you can still get water infiltration now insulation on wire has gotten a lot better
Great job on this video, BTW.
Thanks bud
21:36 - Back when I was in the trade, we would use anti-oxidant compound (Noalox) on Al wire; but, I’ve never seen it used on Cu before.
Good tech work Chris
If you have broken wires next to energized wires there is an inductance between them. The energized wire will induce voltage in the broken ground. Note that this is only possible if the ground wire is completely eclectically isolated from a true ground point. A voltmeter's input impedance is quite high so it will not load the circuit much, so you will get some sort of reading. If you get a voltage on a wire that you think is broken get an resistor of say 1000 ohms and clip it to the suspect wire and then touch the other end to a known good ground point. The voltage measured on the broken wire will go to almost zero.
Next time investigate it with your insulation tester, that will tell everything about the condition of your wires. Like you did several times on compressors and blower motors That also a good method to check your feed in weird situations like this
Man, that was a crazy one. I wonder if that one leg welded itself to the conduit. Would have loved to seen a camera run down the conduit.
It's interesting how things differ across the world. Here in the 230/400V part of the world, I would think that we would had used a three phase extension cord for temporary power. Also it's likely that there would be a sub panel next to the roof units. Also even though it's strongly recommended to use a hose intended for electrical wiring, there are wires over here that are rated for putting under ground without any extra protection. The plastic insulation is rather thick on those. Only downside of those as compared to regular wires are that they have worse fire resistance and they are really ugly as the outer insulation is shaped by the conductors inside the wire.
It would be fun to send a fiber optic camera into the conduit and get a good look at what really happened. Also, the voltages after the broken wire are misleading as there was no load, so the voltages were basically floating
Great work, Chris.
Hopefully they can come out with the refrigerant lines and come out
Water on cables can be a funny thing . clean low mineral water can cause leakage such as in this case but low resistance so not enough to trip . plus its a 30 amp breaker so you need like 35 - 40 amps going through to trip . if it had a RCD (GFCI) that would of tripped due to the leakage
Steel conduit over time ?? Cupping could have cracked allowing ground water to invade the conduit… an I have seen it where the wire coating is pierced but not totally bare an get bleed over through the water but not enough to trip the breaker. So basically the feed wires were under a load but not enough to be a 30 amp dead short.. it took 3 of us to come to the conclusion of bleed over. Water is a conductor but not the same over a distance as a solid conductor.. in our case? The hot leg bad spot was 63 feet from the skinned spot on the ground wire.. it defies logic because we all assume water would completely a dead short . The two electricians said or come to the conclusion that there was just enough resistance in the water to not allow it to be a dead short… 🤷🏻♂️ all I know is they ran a new line an by by problem. But I needle size hole was enough to conduct electricity but not enough to trip the breaker thro the resistance of the water.. 😂 that’s all I know an I was also told that the constant heating and cooling of the power lines underground can cause condensation to form inside the conduit. Due to the fact the conduit is open at both ends, not a sealed vessel. You did a great job at pin pointing the main problem!!!
You can throw peeled cable into water and it will just start boiling it. Current increases with temperature until it gets to boiling at which point it drops and its kind of self regulating. Some water heaters work like that, incredibly dangerous actually.
@@LastSlovenian
Agree an as the leg increases in heat. ohms, law and thermodynamics start to play a part Increasing the resistance of the flow reducing the amp an somewhat voltage flow
I believe ground just needs to be sized to handle the fault current from the largest single circuit in the run. 10AWG ground for 30A circuits checks out.
Very strange how the wires rotted out like that. Your theory of incorrect conduit material makes sense. I'd add that damaged insulation during the pull compromised the wet location tolerance. Entirely possible the insulation was entirely breached and only luck prevented a hard phase to phase or phase to ground fault. But the whole time it sat there boiling underground until the whole set was destroyed. No GFCI so breaker wouldn't care about an extra amp or two doing illicit electrolysis in the pipe!
. I was working on the hvac equipment and I kept getting shocked and I thought I was doing something wrong. Come to find out a well pump was shorted or not disconnected properly, and there was 90 volts on the ground and not tripping the breaker. It was a zinsco panel too btw.
I had a start up on an intelligen system and the install guys had jumped the time delay out, so it would pump down and shut off on LP and eventually lockout. So come to find out, if the evap communicates with the condenser, it has to have a delay to allow the EEV to open.
Conduit rotted out underground. Galvanized can be used underground, thats all we had before PVC was available which is what is usually used now.
23:10
These breakers will trip only incase of a major short circuit to protect the wires, depending on the trip curve it kight even require like 4 times its rated trip current to trip at that instant, and it wont bother with an earth fault, but like in the EU and Asia if you have a whole building RCCB or one for each circuit, the RCCB is like GFCI but fault current should be 30mA normally, could vary with models, this RCCB trips when the current thats going in doesnt fully return, which means that the currenr is going somewhere else like earth so it trips.......
The wire resistance could be also high due to the very bad contacts thus we get low voltage up.
Haha maybe the broken wires were boiling the water in the conduit 🤔?
You can only do what you can!
Two possibility’s for measuring voltage on an open line are Induction or a high resistance path.
If you only have a breaker with a high resistance path it would not necessarily trip as there is no Short. With these wires and using a RCD it would probably have tripped as there was likely more then the typical 30mA to Earth…
It worked as a water heater in the conduct.
With all those electrical problems between phases and down to earth why the heck didn’t the breaker operate. That’s very worrying!!!
Great job 😊
Not so serious comment: next time you yawn on camera, you can say "goodnight" to your European viewers, who are watching this as fairy-tale before the bed
This is why i love uk electrical because we actually test with test equipment we meg out the actual wires to ground and to phase
As you do meg out today, it will not guarantee you from broken wire isolation in future. It can melt from heat, it can be bitten by suicidal mouse, etc...
@@Nyarly_Relyeh Suicidal mouse will require many generations to get through the armour.
@Nyarly_Relyeh if its a regular test you can see signs of wire degridation during testing on a regular basis
@@joshuabest100 Regular test. Regular maintenance. Sounds good for the perfect world..
You can often run a toilet snake down those conduits to clean them out, a small hand or drill operated one
A suggestion for a short: the cooling characteristics of the hats. While this has nothing to do with HVAC it might be a fun and funny way to use some of your tools in way that does produce results but the results are not the sort of things manufactures would care about. .It would something that could pass an unusually boring Sunday afternoon.
if the conduit had water in it at one point in time , the ground wire or the power lead were apparently had a small break in the wire that got worse over time.
It has to pull an amount of amperage higher than the breaker is rated for in order for it to trip the breaker. The corrosion and water build up in-between the conductors is technically a resistor and resistors the flow and reduces amperage. If the conduit had a poor ground then that poor ground would be a resistor. To me, there wasn’t a perfect path to source for it to trip. GFI breakers will trip at much lower amperages to ground.
good quick temporary fix chris you had to get them running
Breaker probably didn't trip because the current was flowing to the broken ground instead of across the hot wire break.
IF you were running it underground you could've gone with smaller wire, as water cooled cables have a higher current carrying capacity
and you've got to love electrical Gremlins
I was thinking if you really want to investigate you could get a boroscope or someone with a boroscope like a plumber or something to check whats going on but that migth be a bit out of the source of the call from the costumer. Great video!
that voltage on the ground is a no load with your meter. So the broken wires and the conduction between them was measured. there was probably very little current.
This is why i am thankful that i mostly deal with plumbing because of stupid shit like this that makes you overthink way to hard not to mention it's going to whole entire thing to re run that line.
That's nuts!