How to Carry out an Insulation Resistance Test of our 1 Way Lighting Circuit

Students training aid for testing insulation resistance. Demonstration shows how to set up your Megger MFT tester and show you how to carry out an insulation resistance test for our 1 way lighting circuit. Test voltage is 500V DC and the minimum acceptable value according to BS 7671 is 1 megohms with further investigation when the reading falls below 2 megohms.

== 🕐 Time Stamps - Cut to the action 🕕 ==

00:00 - Insulation resistance test
00:16 - Earthing conductor needs to be connected
00:49 - Remove all loads, covers on and switches on
01:05 - Switch off RDC's, RCCB's and RCBO's
01:15 - Setting up my MFT tester
02:08 - Testing my leads
03:10 - Why are we testing the insulation resistance
04:08 - Removing loads
05:15 - Testing between line and neutral
05:45 - Testing between line and CPC
05:55 - Testing between CPC and neutral

Videos are training aids for City and Guilds (C and G) and EAL courses Level 1, 2, 3 plus AM2, AM2S and AM2E.

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[zamanraja]

just needed this quick refresher before my test today, thank you man honestly; you're honest, clear and precise. keep it up, Gaz is the best!

[fennybenton]

GSH definitely the best tutorial videos on you tube. Clear explanations by people who know what they’re talking about.

[jameshansing]

As an adult learner 6 weeks into a 2365 course, these videos are awesome and so helpful. I hope one day I can find someone like you to work with/for... Keep them coming... :)

[garethgordon]

Very good point about checking condition of test leads, thanks!

[luluboxingtv]

Nearly finished my install side of my nvq and will be onto my testing section in the coming weeks, these videos are so clear and easy to understand I wish I went to your college

[AntzCollins]

Great videos mate. some of the best I've seen on YouTube! You should be commended. Any videos on fault finding would be another that is greatly appreciated as I find there is a lack of videos online

[Dog-whisperer]

Gaz I think it would be beneficial for the students watching this to show how not removing the loads the possible problems that can acrur such as scude readings and possible damage to sensitive equipment.

[TheDeno]

Thank you so much got my exam on periodic inspection and testing and i needed to see this done to apply the theiry thats in my head.

Your video helped!

[robinj]

As you are doing the test on the bus bar directly and not isolating the neutral form that specific circuit, would you need to disconnect all appliances from all the other circuits so not to damage any equipment ?

[williamreid-hall]

Hello, was wondering if you performed this test on an installation with multiple circuits on it and clamped on to the neutral bar to perform the test for the lighting circuit, would it take in the resistance of all the other neutral conductors on the system? Cheers 🍻

[kazemashrafi]

hi, all wago push fit connector are designed for 450v, what will happen to those connector whan the circuit tested with 500v for insulation test?

[michaelcostello]

Why did you need to turn off the RCD as you had the CB turned off. Was it just an extra precaution or what is the theory ?

[alexmilalu]

I have a question, how do you draw a circuit diagram of one lamp controlled by one switch the show how insulation resistance test is carried out on the circuit

[martinj]

What if there led floods on the circut (you cant remove the lamps)?

[shitfi]

If the circuit is 230v why would we test at 500v? I understand doing 500v for three phase because it's 415v, but why 500v for a 230v circuit?

[iraqviva]

If we have more than a one circuit or mcb do we need to disconnect the pcp or the n from the bar and thanks gaZ for your help

[abscomm]

As the test is only for the wiring to that circuit, should not the regs call for the wiring to be disconnected to ensure that no possible faults from any external sources (such as a faulty breaker etc.) are eliminated?

[rmrgy]

thanks for the video.

why is the insulation between neutral and earth so high?
at tncs shouldn't it be a few ohms?
is it because the RCD is switched off so both the phase and neutral are disconnected?

thank you,
roy.

[djdarrend]

I was told on my testing course that you can short the line and neutrals and not have to worry about removing any lamps or turning switches off ... and to test on 250 .... is this correct

[NghtCrawler]

Hi, enjoy your videos.

Just a question off topic. I did a domestic installer/17th edition course 3yrs ago and was looking for some weekend work (as I work full time) with the hope of full time work down the line.

Any websites or contacts you have for this in the London area.

Thanks
Ross