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The main switch is not bridged it is the CB separated and located at the right side. Are you looking at the 3 phase CB on the very left? If so the underside is the Line side. The Neutral and Earth bars have a bridge, its this bridge that you are removing. This is so that you can test the earthing resistance of the earthing; mains, cable and equipotential separately. I noticed you removed the other question you had which might help explain this more. Your other question about the load side being on top and not the bottom is a good one that many new electricians wonder about. The reason for putting the load side on top is for safety. Imagine if dust or ants create a short and a fire for whatever reason you want your damage to be on your sub circuits where you can easily replace wires and not in your submains or mains that usually underground and will cost more and is harder to replace and repair.

@@lyntinatkin7847 Use the installation verification Standard.

Link: th-cam.com/video/i8bavUrrBx0/w-d-xo.htmlsi=7QCsN_h388ue7xvh

For Complete Installation Bridge A and N at supply. Or Bridge Line and Load if meter. All CBs and RCDs On Disconnect MEN/HWS/Oven elements. Test Ebar to Nbar

At 58seconds I say load side of supply to L1 L2 and L3. Remember also Main Switch is turned on but all other CB and RCDs are off so it's not testing any sub circuits.

It makes sense now! in our pract we don't have a sun main to check. Only consumer mains and final sub circuits:) thank you

@@warrenkelly4561 All good. Just remember lots of places do run submains. As long as you get bigger picture.

50secs -Main Switch 4mins -Submain. This is a CB that runs cable to another location like a shed or outdoor area There is no service fuse on here. A service fuse runs along service cable (Incoming Supply) My service cable is the extension lead cable that I had removed at the very beginning of this test.

Check out the installation diagrams on this website. It may help. www.electricaltechnology.org/2021/03/wiring-consumer-unit-distribution-board-rcd.html

Rewatch @4mins Submain is not on a RCD it's a CB so you need to remove connected N from N bar. Need to test N and E to Active E to A and N to A. The Neutral was removed at the Neutral bar. Usually your load side comes out from the top. This is because dust and bugs can accumulate on top so if you have a fire it's best it happens on the more protected side.

Yes at 1.47 I say all the resistances you'll measure are under 1 ohm referring to getting your tester tested properly it wasn't meant to be specific to Main Earth or equipotential.and includes all test readings. Technically final sub circuits can go up as high as 3 or 4 ohms and be a pass according to AS/NZS 3017:2007 Table 3.2. Main Earth and equipotentialbonding does need to be least than 0.50 ohms. Watch from 4:00. All final circuit resistance readings need to comply with earthing Table 3.2 in AS/NZ3017. The limit of ohms is actually dependant on the size of the cable, the CB size and type. So some cable with a reading of 0.4 ohms will actually be a fail. Some with a reading of 0.8ohms is actually a pass. Get familiar with the table you will need this table during your exam.

@@theea3466 thanks for replying. I was being a smartarse. I think you are doing a fantastic job putting yourself out there as an apprentice and doing a testing presentation. Shame some tradies weren’t as dedicated to the trade like you. Just a pointer on earth resistance there is a sub circuit where the earth resistance reading is above 1 ohm. Maybe a reference to Table 8.2 (from memory) to check what the maximum resistance allowed for the circuit under test. Keep up the brilliant work. Cheers Steve

@@stevechadwick180 Table 3.2 goes up to 6 ohms in 1mm cable but got to keep in mind limits and rules in AS 3000 in regards to cable size for power and lights. If the thinking is that the final sub circuits just always less than 0.50 ohms apprentices will struggle to pass.

@@theea3466 When we delve in and only good tradies will delve in and start researching and asking questions it gets deeper. I noted you said you need to ascertain if the installation is new or old and this will make a difference to the insulation readings. 50Mohms opposed to 1Mohm. This would also need to be cross reference with the SIR (service and Installation rules) unless working in WA or Qlds where they have there own name for this document where mains are required. To have a reading of no less than 50Mohms ( that’s from the VIC SIR and from memory). Also another one for old players the same question asked when performing the main earth and equipotential resistance test prior to the AS/NZS3000:2007 the reading would pass if it was 2ohms or less. So doing a test on an old installation 2ohms may be acceptable.

@@stevechadwick180 Thanks Steve. I do mention the difference between acceptable levels between new and old installations and say to ask your exam officer if they don't tell you its new or old. I made so many videos I'm sure its in the first one. I retook a few videos and I didn't edit so im hoping its there and not in a deleted video.

It's a new installation. You have run the cable but it's not connected at Connection Point or Point of Attachment. You have to check the entire installation before connection. :)

Thank you so much that makes sense now @@theea3466

Be that ring circuit in circuit are? 😎😁

😎😁💪🍻🍕 Good luck to all the lads and ladies studying hard. Should all be proud of yourself.

These test are performed to check system integrity before any supply power is connected. So no you don't need rubber insulated gloves. E.g You have just wired a new installation on a new house, your checking system before supply is connected.

Firstly, there is no scenario in which wearing PPE is wrong. If you want to make it a habit to wear gloves, go for it. Also, you should note that when running an insulation resistance test, your tester is pushing 500V of DC current through the installation. You should definitely be careful when conducting this test.

Yes and No. I had to pinch parts for jobs I needed to do.

So glad to hear bud.

No I don't sorry bud. When you sign up for an apprenticeship a teacher will go over these practice tests with you.

AS/NZS 3017 Page 8 says test equipment should comply with requirements of IEC 61557 and Page 6 states 3017 refers to IEC 61557 Parts 3 & 5. 4.3 is saying your testing range needs to be larger than 0.2ohms. Ideally you'd use analogue ohmmeter as figures show in AS/NZS3017 My multimeter reads more than 1 decimal point as I show in the video and multimeyer ranges do go below 200mA. Different multimeters have different ranges, accuracy and resolution..

Great Question. I have no pipe on here just earth stake. What is equipotential bonding? What is it attached too? In this case it's the metal water pipe and its attached to my Hot Water System. Your water pipe may have a parallel path so that's why earth comes off the HWS.

Depends on why your doing it? Keep in mind I'm not a teacher but will explain it the best I know how. If you know that N is sound and not intermixed you can attach the Neutral to earth at either the MSB or sub board. Then go to the other board that's not attached remove earth and Neutral from bars and test resistance if the resistance of both cables are lower than the maximum resistance according to table for cable size and CB size you know it complies. If it is strict testing like in capstone. You'd use a trailing lead or in fact any cable you have that is long enough to reach your MSB and Sub board. Step 1 Test the resistance of your trailing lead or cable. Write the ohms result down on paper or cardboard or enter into your phone. Step 2 attach lead or cable to the underground earth cable at one location either at at MSB or Sub board. Ask yourself what am I attaching this lead to? Have I attached the earth cable only for this cable under ground? Then walk the trailing lead to the other board. Remove the earth cable for that cable underground out of the earth bar. Test between Earth of the underground cable and trailing lead or connected wire in cable. Write the result ohms down. Then subtract the trailing lead or cable reading that you wrote down before. This will leave you with your restistance reading for just the underground cable. Does this help? Please don't be afraid to ask your teacher. Chances are if you don't know half the class won't.

@@theea3466 Thanks heaps great reply

If there is I haven't seen it yet. I was going to make a video on Main Switchboards so I'll try to get that happening. Things are a little chaotic with the flooding at the moment.

It's in the NSW SIR and it's specifically states this for brand new installations that have brand new service conductors. Brand new wiring shouldn't have any resistance other than the wire itself. What increases resistance? Moisture, leakage..etc. SIR. 1.12.3.1 Minimum Insulation Resistance. 'The insulation resistance between conductors and between conductors and earth of new services shall not be less than 50 megohms when tested using a 500V DC insulation resistance tester.'

I do believe this is for the service side (level 2 work) as 1.12 ‘Provision for services and service equipment’

This is why I created the videos. I was just really lucky to have some good teachers at my TAFE who did the precapstone tutorials who explained it in a commonsense way.

Good luck bud. If there is any topics you need help with let me know.

I will thank you. Great to see other female sparkies out there smashing it. I’m a 4th year at the moment.

Wishing you the best of luck. Let us know how you went.

So many kyoritsu meters. You'll need to use a Meggar for Insulation resistance. They may provide one for you. Find out what brand they use and be familiar with it. You'll need to know how to calibrate it and test the voltage. In regards to the beep... Totally fine. The beeping is good when testing continuity it means you know there is a path without having to look at your screen. You'll just have to check by viewing the reading that you have resistance for continuity. With all other test you need to read your results and determine if the reading is appropriate.

How did you go?

Yes. When you test for complete installation your testing the entire system. Mains + Submains +Final subcircuits. If you test at the mains with everything connected your testing the entire installation. If this passes everything is fine. For the capstone you need to test each section to show you know how. Remember IR test is checking for any insulation leakage under pressure. The rules state all live conductors needed to be tested with earth. Neutral is considered a live conductor.