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  1. R

    Insulation resistance check

    Hi - I have a Warm-up underfloor heating system. And it's stopped working. I did a basic resistance check - and clearly there's a problem (shows just 18ohms when it should be nearer 200). Warmup have said they can send an engineer around to lift a tile after doing a thermo heat check...
  2. G

    Insulation on swa in a board

    Hi gents Whilst I am qualified as an electrician I am a maintenance engineer so don't do much installation work hence seeking advice here. I recently installed a new 3ph distribution board for a new machine. As I don't have my testing and inspection ticket another person did the minor works for...
  3. C

    Thermal insulation covering cable

    I'm doing a garage conversion. 70mm insulation on block then an inch gap battened on top, then 35mm insulating board. Where's best for the cable to go in terms of derating etc... Cheers.
  4. Sean Kennedy

    New Build regs on insulation

    Hi Has anyone had any experience regarding insulation in walls on new builds as to what size mcb they are using for ring main circuits. I have checked the regs and seen that 100mm > insulation derates the cable capacity a fair bit. The builders are using 140 mm in the walls. I have pointed this...
  5. E

    Insulation Resistance Results

    Hi, I’d like some clarification with regards to insulation resistance results I’ve got. Carrying out initial verification on a new ring final circuit. New cable, 9 new MK double sockets. r1 - 0.43 rn - 0.42 r2 - 0.68 R1+R2 - 0.28. Carried out insulation resistance test: L-N - >2000 MOhms L-E...
  6. HoverSPRX

    "Clever" client derated the cables!

    So I'm currently sorting a CU change and kitchen rewire while also fixings some bodges by a have a go client, came back this week to discover that he has decided to insulate the void between ground and first without mentioning it. Now this has derated all his cables by half as they are tottaly...
  7. T


    Hello, has anyone noticed in the new GN3 that any reading below 20 Mohms now has to be investigated or is this a printing mistake as it used to be 2Mohms? Thank you Tom
  8. Bobby34

    Insulation Resistance testing method

    Good afternoon, apologies if this has been covered before i've not long joined so gradually finding my way around. I have my Part P assessment coming up on a new installation and would like to hear some opinions on how people carry out their IR tests. In guidance note 3 it gives an example of...
  9. L

    Basic insulation _________

    Is twin and earth classed as double insulated? If it is, is it necessary to use when you using ADOS when the regs say basic protection can be provided by basic insulation.
  10. L

    Trainee Basic insulation _______

    Is double insulation cable necessary such as twin and earth if under automatic disconnection of supply it states that basic protection can be achieved by basic insulation only. Thanks
  11. J

    Insulation Resistance...

    I am just working through my understanding of the insulation resistance test, and I want to find out the best way to do the combined Live-Earth test where the Line and Neutral conductors are connected (joined, or however it is best described) through one probe of the tester, and the other probe...
  12. D

    Domestic Bathroom downlight insulation coverable + exisiting CPC cut

    Pleased to find this forum, my 1st post! I will get an electrician in for this to make sure it's safe and tested but I want to understand what's right before getting a quote/posting a job. Previous owners had downlights installed in the bathroom but a later test certificate identified the CPCs...
  13. Adam_92

    Insulation restistance on heating system

    Hi, I do not work on a lot of heating systems but when doing an insulation restistance test on a S plan heating system do you only remove the digital programmer?
  14. N

    insulation resistance test on shower circuit with neon isolater

    On a new install of a shower circuit, with a neon isolater, is it better to use choc blocks to bypass neon isolater or would it be ok to just test live-earth (live being neutral and live combined) and miss the live-live test? If testing just live-earth, would you write it down in details of...
  15. B

    Is there really no right way to work with down lights and insulation?

    Hi All, I'm kind of hoping to get confidence in my decision to have spots fitted into the ceiling of our new extension, but keep coming across different advice...help would be welcome! We're looking to fit 12 LED spots (Aurora Pro 6w) into a lean-to pitched roof, split into two circuits on...
  16. naylorpd

    Insulation resistance test issue

    Back in 2013 I had a Domestic Electrical Installation Condition Report done on my rented property - nothing horribly major but one thing I didn't understand... I had a C3 code for "0 ohms readings for I.R test for sockets & lighting (unable to remove all loads sockets, lighting had electronic...
  17. A

    replacing pmmc unit of waco 2.5kv insulation tester

    How can I do it? Where can I find PMMC coils?
  18. haptism

    Low insulation reading

    Testing a ring earlier and found 0.8M ohm at 250v between (L&N) - E. This wouldnt be a neon causing this would it as im testing between L N (joined) to E ? I have not yet tested between the three individually. This low reading is making me hope somethings still connected, there is a digital...
  19. T

    How to bypass an RCD and carry out an insulation resistance test on a circuit

    Hi all. I'm a 4th year electrician currently awaiting to finish my trade test. (FICA in Scotland) the only parts I have to pass is the testing part and fault finding. I'm currently studying testing as this is something I have done the minimum of onsite. Could someone tell me how I would...
  20. haptism

    Insulation properties of heat shrink, and tape

    Have question thats been on my mind for a while. Does anyone know if; at 250 -500 v, a single layer of heat shrink, or a single layer of insulation tape for that matter, covering a bare conductor, sufficient insulation against ?? direct contact/a shock ? It seems a bit thin in comparison to to...
  21. joel89

    Fluke 1507 Insulation Tester

    in a used condition, used about 5 times in total no longer needed as I have an MFT. Paid £450 about 2 years ago! Comes with carry case, croc clips, leads, user manual. I will post via tracked courier I think its around £9 tracked. Offers please
  22. TonyJohnson

    Isolation transformer and insulation monitoring device in horse box/bar

    The regs state 717.413 a Isolation transformer and insulation monitoring device should be used. Are there any guidance notes on type or makes i should be looking for. I see you can get 230V primary 230V secondary boxes but i'm also not sure on which to get in terms of load.. I'm inspecting this...
  23. kkkkk

    Fibreglass insulation safety

    Hi guys What do people find is the best protection against horrible fibreglass insulation - I always seem to be left coughing and itching!!!? I do wear safety gear, but nothing seems to be 100%. :)
  24. F

    (DIY) Extending the ring up the wall (insulation?)

    So, I'm now on my second electrical project (after the success of adding a double socket to mums attic!). In my "computer room" I'm using two extension leads to power 7 or 8 plugs, all from one single socket in the room. One of these plugs is for a powerful PC, the rest are for low power...
  25. N

    Insulation resistance - strange readings

    Im getting some strange reading on a new circuit(ring main) ive installed and i was wondering if anyone else had experienced the following. insulation resistance at 500v on L-N is >500mQ (which is fine) then insulation resistance between N-E starts at 400 then climbs to 500mQ then insulation...
  26. T

    Insulation over LED downlights

    Sorry if this has been asked before - couldn't find anything using the search function. After fitting LED downlights, can they be covered with loft insulation or will that cause a fire risk?
  27. S

    NO switch insulation resistance failure

    How often do we usually have insulation resistance failures on an NO switches leading to unexpected starts?
  28. gazdkw82

    Single brick wall insulation options

    We have a small toilet downstairs that had signs of mould. I've decided to pull the plaster off. I'm glad I did because it was slightly damp in places. I think this is mainly because 1. It's a single brick room and 2. They just nailed the plasterboard to the brick leaving a gap of round 10 mm...
  29. J

    Failed insulation on Fan

    hi guys, Could someone please tell me why the ‘insulation’ has failed on this pat test please? I thought over 1MOhm was ok? The test is on a fan in a dental surgery. Thanks
  30. B

    3 Phase Insulation Resistance Test on motor & TP & N skt help

    Looking for some advice on how to carry out a IR test on a 3-phase motor and a TP & N skt, these are parts of a module I have failed on a test and am looking to see where I am going wrong and what the normal procedure for carrying out this test would be?
  31. R

    Downlights and Loft Insulation

    I have these downlights installed under loft insulation with halogen GU10s. They are marked as fire rated and fire rated under insulation, but the installation just doesn’t look safe? I’m wondering if i should convert them to LED bulbs (that's happening progressively as the halogens blow anyway)...
  32. G

    Insulation coverable downlight

    Hi, I've got a customer who wants downlights installed in their kitchen/dinner. However the ceiling has celotex or equivalent insulation installed above it. Has anyone come across any suitable downlights that can be covered by celotex? Also just to make things harder there isn't any access from...
  33. MarkRibbands

    Insulation resistance failure on rubber flex. Why?

    Two years ago I installed some garden lighting, using u/g SWA to Wiska boxes, then 3-core 0.75mm rubber flex downleads from each LED fitting. This week the 30mA RCBO kept tripping. I assumed a luminaire fault, or moisture in a Wiska box, but no. It was leakage across all three cores of one 10m...
  34. B

    Insulation resistance testing

    Hi have AM2 next week and just need some help, 3 phase TP+N board, two way and intermediate lighting circuit with 3 switches obviously and one light, doing a global IR test, the lighting circuit say is on L1, so I’m testing all other circuits at once too do I have to switch my switches for every...
  35. Sparky_marky2

    Fault finding - insulation testing

    Hi everyone, did some insulation testing on my mates house as his RCD was tripping manage to isolate it to the ring circuit, Live-Earth for the ring circuit came to 0.01Mohms and all appliances have been disconnected and removed. However I have disconnected the Live-Earth behind one socket...
  36. shinypen

    Attached bell wire to rendered external insulation

    Hi. I'm pricing up a job. I need to run bell wire up the outside of a newly rendered and externally insulated house. Never touched this before and I'm worried the clips won't fix in securely or will damage it. Is this the case? Any one got any experience /tips? Thanks.
  37. Taylortwocities

    How not to run cables through insulation

    Just saw this. Great demonstration of how NOT to install insulation round electrical cables. No consideration of the CCC of the cable. Sorry pete, I know this is your job, really.....:D
  38. Sahiru Dilan

    Please help me regarding these topics.

    I have an assignment on Saturday. There are somethings that I do not understand. So Please help me to figure them out. 1)What is the exact value as mentioned by regulations for High Voltage and Low Voltage? 2)If an insulation is good three people should sign to verify. What are those people...
  39. J

    new build 1st fixing with insulation!

    afternoon guys how would you go about 1st fixing this... would the builder usually batten/stud out- then board- or will they be wanting to board straight onto the walls?? only meet the client so far (not builder)
  40. R

    2.5mm ring main and Celotex Insulation

    I am building a garden office and currently have 25mm Celotex in the walls. I am running the ring main around and then want to add some more Celotex. My question is how much of an air gap do I need to leave for the ring main?
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