Easy Guide to Insulation Resistance Testing, Fault Finding and How to Complete the Test Sheet

How to carry out Insulation Resistance to the latest wiring regulations and complete the schedule of results. Fault finding for L-N, L-E and N-E. Great refresher or just curious if you have an exam coming up such as 2391 or AM2 or AM2S. Includes Safe Isolation procedure. All level 3 students should know this. Calculate R1 + R2, fault find by looking at the readings.

[@abmmuhit]

Honestly, the best clear , practical vid I have watched so far. You make physics jargon understandable for newbies

[@sparkyhelp3997]

Thank you, please like, share and subscribe. Again many thanks, glad it helped... more coming soon.

[@corfiot21]

Brilliant video. electrics can be overwhelming sometimes but your demonstration certainly explains things really well.

[@sparkyhelp3997]

Glad you enjoyed it, please let others know of its exitance. Please Like, Share & Subscribe.

[@cormacsnow2515]

You explained it very simply thank you it’s hard to find videos that explain things properly🎉

[@sparkyhelp3997]

Many thanks, it is much appreciated. Please Like, Share & Subscribe

[@michaelandrade170]

Best video. Doing a course at the moment for my level 3 nvq and this is the best hands down keep it up 💪🏻

[@sparkyhelp3997]

Thankyou, I like to believe I do this for the thinking electrician. Good luck on the course an please share with like minded people. Please take the time to Like, Share & Subscribe.

[@pathogen1985]

Great video very informative. I’m an apprentice myself and this has made it clearer. Keep up the good work

[@sparkyhelp3997]

Thank you, glad it has helped, please share with others - more to come and good luck.

[@日下亮一]

My name is Kusaka of Kyoritsu Electrical instruments works, ltd. I learned a lot from watching the video about measuring instruments.

[@sparkyhelp3997]

Thank you

[@jimm533]

Great video ive got my 2391 practical coming up and this really helps

[@sparkyhelp3997]

Glad it helped

[@lewishumphries2893]

How did you get on?

[@mohammedgulbhar684]

Your video was brilliant I’ve learnt a lot from it well explained step by step magic👍

[@sparkyhelp3997]

Glad you liked it, please like, share & subscribe.

[@John12369]

Always getting confused on the different ways you can do insulation resistance testing. Can u do a video to show all the different insulation resistance tests.

[@sparkyhelp3997]

Many thanks. Can you tell me more, are we talking three Phase? Please Like, Share & Subscribe.

[@eldernuru22]

Thank you so much for this video. Very helpful. I await more details of this topic.

[@sparkyhelp3997]

More to come!

[@sparkyhelp3997]

'Hi, great explanation and very good video. I have a question when testing ring circuits in terms of insulation resistance. In a ring circuit shall one test on only one end of the L and N cables? Or can one link the two L ends and the two N ends and test across them?' Had this question. The circuit can be left connected in the DB and tested, if you wish to test the circuit separately it is best to test both ends at the same time. If you did test only one end of the circuit the other end would still be tested as it is a ring, but you may give yourself a shock or it may touch something to give you as false reading.

[@michaelcostello6991]

At 4:12 in video the neon isolator appears to be switched off. How then can the neon light come on under IR test ? Can you please clarify. Thanks

[@sparkyhelp3997]

Well spotted, this fused connection unit had the neon configured on the incoming supply. Please Like Share and Subscribe.

[@michaelcostello6991]

@@sparkyhelp3997 Thank you for clarifying.

[@alivaux1033]

Thanks for your effort, good content & delivery

[@sparkyhelp3997]

Thanks for watching!

[@alanmarriott9216]

Brillliant video!! Could you explain please why connecting line and neutral together to earth on circuit with items connecting works please and doesn’t damage items? Many thanks

[@sparkyhelp3997]

The electrical loads work when a supply of the appropriate voltage is applied to Line & Neutral. When 500V is applied to L-N it will measure the resistance of the load and therefore provide a reading which could indicate a fault and or you will damage the equipment as it was never designed for 500V to be applied. Hope this Helps, Please take time to like the Video and even better Share with others and Subscribe. Many Thanks.

[@alanmarriott9216]

Ok thanks but can I ask how putting line and neutral together and testing to earth also stops items being damaged please? Surely by putting line and neutral together and testing to earth you wouldn’t find a short between line and neutral would you? Many thanks mate

[@sparkyhelp3997]

L & N are connected to the same test lead (at the same time) other lead to CPC (This is what PAT testers do)

[@adeniyimuhammad7298]

Hi great video, although i am a bit lost as to why theres a 500Mohms resistance between the N and E busbars, i thought N and E are supposed to be connected together from the main supply (either a transformer or a generator).

[@sparkyhelp3997]

Thanks for watching, please share with like minded people. The reason is the main switch is double pole, therefore any main switch that also breaks the Neutral will be disconnected. Again thanks for watching please like and subscribe, check out my other videos.

[@dees9295]

Apologies if this is a silly question but when doing the fault finding N-E test 19:00 mins into the video why didn't you turn off (down) the MCBs like in the fault finding for L-N and L-E? Many thanks for the videos very helpful indeed

[@sparkyhelp3997]

Hi, because the circuit breakers only break the line conductor.

[@dees9295]

@@sparkyhelp3997 many thanks for answering

[@mrpoo7651]

Great video but I am confused at 15:53 Fault finding L-N. It looks like you are probing on the 32A breaker in order to see if there is a fault somewhere else. I am sure I am just not seeing it correctly but if you or someone else can hep, I would be greateful :)

[@sparkyhelp3997]

Hi, If you look at the circuit Breaker you will see they are all switched on. Therefore all circuits are being tested (Ensure Main Switch is off) The test probe can be on any terminal and all are part of the circuit. Hope that helps. Please Like, Share & Subscribe.

[@jasonbrown825]

Thanks. Looking forward more videos like this

[@sparkyhelp3997]

More to come!

[@panayiotispanayides2141]

Question , when you tested the L-N, your meter was in the PE and L positions, should it not have been in the N and L??

[@sparkyhelp3997]

When carrying out an Insulation Resistance Test you can only use two leads - these are L & PE. Hope this helps. Please Like, Share & Subscribe.

[@michaelcostello6991]

Thank you. Really helpful video

[@sparkyhelp3997]

Glad it was helpful! Please like, Share & Subscribe.

[@freezefoot]

Another Learner Question : If you link L-N( to negate damage to sensitive equipment) , test to cpc & get good results across the board can you still legitimately fill in your two columns on test sheet L-L & L-CPC or do you still have to do those two tests seperately? Thank you again

[@sparkyhelp3997]

This was a grey area in the older regulations - you definitely test Live - CPC. The new regulations (which I will have to do another video on), now clarifies that all conductors must be tested (this will mean linking wires before electronic equipment connected and testing all conductors, and then after connection of equipment testing again at a lower voltage or linking) - sorry it is not a straight forward question to answer, but I hope it has helped. Hope that helps - Please like, share, subscribe or if you really want to buy me a coffee! Thanks

[@Khanjan-si8me]

What is your advice how to test if you can't remove lighting sockets or Smoke alam what should we done then?

[@sparkyhelp3997]

See other response - good luck

[@MrRinof]

Hi sir Video amazing IR test Sheet can I get From You 🎉🎉

[@sparkyhelp3997]

Hi Thanks for watching, please share with like minded people. Please visit IET website and search wiring regulations forms - you should be able to download them. Please check out my other videos and maybe even like and subscribe.

[@drpantastic1969]

Wish the camera was a little lower did you test from the buzz bar or just on of the live terminals.i think your saying because all switches are closed it does not matter where you test from. A little response would be helpful if possible thanks for the video much appreciated

[@sparkyhelp3997]

You are quite correct it does not matter where you test from as all the switches are closed (just do not test on the incoming side of the main switch as this would probably be Live). All the test can be completed (if all circuit breakers are on) on the outgoing of the main switch, Line and Neutral and the earth bar. Hope that helps, please like share and subscribe.

[@Skelton1996]

Would it damage any loads connected if you are only performing a 500v test when testing between live conductors to earth?

[@Skelton1996]

I know if you join them together and test to earth it doesn’t but does it when you test them individually to earth

[@sparkyhelp3997]

In would always be best to test lives - earth, in theory live to earth should not make a difference, but best to err on the side of caution and test them together - to truly answer that you would have to know the the electrical connections of all appliances or connected loads. Hope that helps. Please Like Share & subscribe.

[@Skelton1996]

So a 500v live to earth test doesn’t damage connected loads proving electrical connections have the right polarity?(connected to the proper terminals) I know lives to earth would be a safer test when loads are connected but surely it wouldn’t rule out if the fault is between line to earth or between neutral to earth? Only asking this incase a situation may arise where disconnecting loads isn’t practical or possible.

[@sparkyhelp3997]

Addendum, if there is a neutral to earth fault or line to earth fault, if they are carried out separately, then in this case it could damage equipment - sorry thought about it again! So stick to Lives together to Earth (this is how PAT testing machines carry out this test). Hope that helps.

[@Skelton1996]

@@sparkyhelp3997 really appreciate your replies I’ve liked and subscribed I’m starting testing after Christmas and just trying to grasp my own understanding

[@LinzyMac]

Is there a reason that for L-N you testing the supply side of the live in the MCB and for L-E you tested the load side?? Forgive me if this is a stupid question

[@sparkyhelp3997]

Hi, no such thing as a stupid question just stupid answers. Test on the load side if able to, to test all the circuits at once, but remember to have all the circuit breakers on and all switches on. Remember the supply side of the isolator will probably be live. Hope this answers your question.

[@michaelcostello6991]

Good question

[@freezefoot]

Thank you . Great Learner/apprentice video. Learner Question (hopefully not stupid) : @19:40 why did you not get 500v DC running into you when holding conductor onto probe with your finger?

[@sparkyhelp3997]

In order to receive a shock you need to complete a circuit, so I would need to touch both (500V DC from tester). Don't try this on your system at home as the neutral is earthed and you will get electrocuted. See earthing systems for a better understanding. Hope that helps - Please like, share, subscribe or if you really want to buy me a coffee! Thanks

[@Connor8764.1]

Going to be sitting my am2 in a few days. Do you think they would allow to test this way (testing all the circuits at once) instead of testing one by one. Of course if I found a bad circuit like you did yourself (turning breakers off 1 by 1) or by then testing circuit by circuit then I would go for the fix. But as a collective for testing my circuits this could save a lot of time. Thanks

[@sparkyhelp3997]

If you test all circuits collectively (dis-board at a time) with all vulnerable equipment removed, you will be testing to BS7671 - the correct way. Just make sure you test RCBO circuits separately if they are vulnerable to test. Good luck and read the specification carefully when doing your AM2.

[@Connor8764.1]

Sparky Help yes so any RCBO’s I will turn off so to not fry the breaker correct? Or can it still do damage potentially even when turned off. As I believe the board will be 3 phase as there is a doll motor so there will be no RCD switches. Cheers for the response.

[@sparkyhelp3997]

Yes turn the RCBO off and make sure you test all combinations of three phase (exactly as you would do when carrying out safe isolation - sorry I did not cover 3 phase in the video). Make sure you then test the RCBO circuit separately.

[@sparkyhelp3997]

And don't forget to test the other side of the DOL starter.

[@krazylad84]

Thanks for sharing. nice video

[@sparkyhelp3997]

Glad you liked it

[@pinaconorth007]

Excellent

[@sparkyhelp3997]

Thank you so much 😀

[@dgceremony]

Hi Sparky Help. I just wonder why you have different results between 14:03 the test result for L-N is 500MΩ (insulation Resistance test) and 16:02 where you have the test result for L-N is 1.72MΩ (Fault Finding). Thanks in advance.

[@sparkyhelp3997]

I had introduced a lower resistance in the circuit to demonstrate how to find the circuit in question. Hope that helps. Please like, Share and Subscribe.

[@ajmedia559]

Binge watching these testing vids on KZbin because my college teachers are trash

[@sparkyhelp3997]

the thumbs up is for watching the videos - not for college teachers being trash :( Glad you find them useful

[@Woodkin007]

The main problem is doing this routine is that in reality in a lived in property is that you'll never unplug or isolate everything. Even joining live and neutral and testing between cpc and joined lines you can still get suspicious readings from electronics/surge protectors in socket adaptors/ neons blah blah blah. So say you get 0.65 , you disconnect all sockets/neons..it ain't happening. At this stage do you look for a fault or spend hours disconnecting things to ultimately tell the client that you're charging a days wage for just disconnecting and reconnecting all things that could give a curious reading. These desk jockeys on KZbin saying inane things like disconnect all electronics? Come off it.

[@sparkyhelp3997]

Are you talking about a Condition Report or an Initial Verification. If you get 0.65Mohms are you saying you would leave it? In amendment 2 of BS7671, Insulation resistance testing has become more involved - the regulations are just brilliant!!! As long you know how to test properly and have a full understanding what you are doing what each and every one of does is entirely up to them, but I reckon if they were being assessed they would do it as per BS7671.

[@electricalstuff259]

Why don't you need to zero the leads?

[@sparkyhelp3997]

Insulation resistance is measuring Mega ohms and the leads are likely to be milli or even micro-ohms therefore, there is no point or often facility, to zero the leads for an Insulation resistance test. Please Like, Share & Subscribe.

[@abdessamedghettas7167]

Thanks

[@sparkyhelp3997]

No problem, Please Like, Share & Subscribe.

[@saidumarah9857]

Wen soccket is function and the such is not function what happy

[@sparkyhelp3997]

Thanks!

[@Khanjan-si8me]

Estate agent only pay £90 per EICR how can you spend so much time removing the things and put it back on ?

[@sparkyhelp3997]

Read BS7671 Part 6, periodic inspection for information on EICR's "Periodic inspection shall be carried out without dismantling, or with partial dismantling, as required, supplemented by appropriate tests..." It is important you set out limitations with the client. It is not necessarily a full initial verification.

[@zippymo672]

That is the fee asian estate agents pay. I wouldn't get out of bed for £90 for an EICR.