EICR Code for working RCD with non-functioning test button

[magnoliafan89]

Shouldn't you be testing the test button first before using a tester??

I was taught in my 2391 that if it doesn't trip on the test button its a c2

 

[radiohead]

Shouldn't you be testing the test button first before using a tester??

I was taught in my 2391 that if it doesn't trip on the test button its a c2

Some might say, yes.
But there needs to be an application of common sense. I already made the point that where an RCD is in place but not actually required as additional protection it would be very difficult to justify it being potentially dangerous

 

[HappyHippyDad]

Lap is the screwfix brand, It looks like they have stopped making consumer units and the accessories.
Here is one on ebay Lap 63A 30mA Rcd | eBay - https://www.ebay.co.uk/itm/Lap-63A-30mA-Rcd/174101048101?hash=item28893b2b25:g:LmQAAOSwjyJd1CbC,
although if it's just a normal din rail inside the enclosure then I would be fitting another brand of RCD along with the same brand MCB rather than buying a second hand RCD from ebay.
Not sure what's going on with the top of your CU, is that some kind of sealant?
Also, it looks like the Main switch is designed to be on the left hand side of the board, is it? if so, how did you get the bus bar to fit?

 

[Dartlec]

Lap is the screwfix brand, It looks like they have stopped making consumer units and the accessories.
Here is one on ebay Lap 63A 30mA Rcd | eBay - https://www.ebay.co.uk/itm/Lap-63A-30mA-Rcd/174101048101?hash=item28893b2b25:g:LmQAAOSwjyJd1CbC,
although if it's just a normal din rail inside the enclosure then I would be fitting another brand of RCD along with the same brand MCB rather than buying a second hand RCD from ebay.
Not sure what's going on with the top of your CU, is that some kind of sealant?
Also, it looks like the Main switch is designed to be on the left hand side of the board, is it? if so, how did you get the bus bar to fit?

I almost always avoid buying a used item, though there have been occasions when there is not much option. I assume LAP were rebranded, I do have a document somewhere that lists the original maker so may chase them down - they may well end up being one of the makes that wholesalers often rebrand.

The busbar is installed as normal right to left (no pic sorry) - just shows the quality of their product that they printed the ON/OFF on the wrong side of the enclosure .

The stuff on top is sealant to maintain IP rating - these days I'd use a gland or a wiska fire proof connector - I think the hole may have been non-standard size at the time maybe...

 

[Dartlec]

Here is one on ebay Lap 63A 30mA Rcd | eBay - https://www.ebay.co.uk/itm/Lap-63A-30mA-Rcd/174101048101?hash=item28893b2b25:g:LmQAAOSwjyJd1CbC,

Oddly, the test button on that one is in a totally different place to my one. Did they change suppliers during their run? or maybe the 80A and 63A RCDs were from different suppliers....

This was a one off experiment at the time because they were on offer I think - and there was probably a reason I never installed any more LAP.

Some of their stuff isn't so bad - the sockets are basically rebadged BG - and their GU10 LEDs are my standard go to now, but it was probably wise for them to stop branding RCDs/MCBs.

Toolstation still do it with Axiom, but I'm fairly sure they are just another common make rebranded.

 

[telectrix]

The enclosure does actually say LAP,

not when you have attached a RCD test sticker over it.

 

[Dartlec]

Shouldn't you be testing the test button first before using a tester??

I was taught in my 2391 that if it doesn't trip on the test button its a c2

I can see why C2 is the 'easy' choice and maybe even the right one, but I find the discussion of why has been interesting - I always prefer to think things through rather than fill by rote, or because everyone else does it without knowing why.

The absence of a RCD where not needed to meet minimum Zs requirements doesn't seem to pose a 'potential immediate danger if a fault develops'.

However, if any device is potentially faulty in one aspect, can it be considered safe in other aspects.

Changing it is not really the issue for me, it's whether using C2 as a way to 'force' something to be changed that may not be dangerous is a valid use of the EICR (it may well be just to be sure)
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Also, it looks like the Main switch is designed to be on the left hand side of the board, is it? if so, how did you get the bus bar to fit?

You know, you now have me doubting myself. The RCD you linked to doesn't have clear L or N markings on so my one is likely the same. If it was wired reverse to how it was designed, would it trip under a meter test, but not by the button?

 

[HappyHippyDad]

I can see why C2 is the 'easy' choice and maybe even the right one, but I find the discussion of why has been interesting - I always prefer to think things through rather than fill by rote, or because everyone else does it without knowing why.

The absence of a RCD where not needed to meet minimum Zs requirements doesn't seem to pose a 'potential immediate danger if a fault develops'.

However, if any device is potentially faulty in one aspect, can it be considered safe in other aspects.

Changing it is not really the issue for me, it's whether using C2 as a way to 'force' something to be changed that may not be dangerous is a valid use of the EICR (it may well be just to be sure)
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You know, you now have me doubting myself. The RCD you linked to doesn't have clear L or N markings on so my one is likely the same. If it was wired reverse to how it was designed, would it trip under a meter test, but not by the button?

Now that's an interesting point. @lucien will clear it up I'm sure .
I've read so many threads about swapping the line and neutral around on an RCD and I'm still not sure if it can or can't be done!

 

[suffolkspark]

Shouldn't you be testing the test button first before using a tester??

Meter first, test button last, this is because if you have a sticky or slow rcd, the test button could free it up before you test, and you would never know that there was an inherent problem. That's what I was taught anyway

 

[pc1966]

I've read so many threads about swapping the line and neutral around on an RCD and I'm still not sure if it can or can't be done!

For those with the white "functional earth" they should trip immediately on L & N swap as they would see a faulty neutral line. But not many have that feature and it is a bit of a pain to wire in.

For 2-pole RCDs otherwise the L&N swap should not make much of a difference and some have no indication of which should be used. However, for 3-phase it is a significant issue as potentially the RCD could be powered from 400V instead of 230V if N was swapped for L2/L3.

Quite probably @Lucien Nunes will have more to add!

 

[Andy78]

Was the test button function tested with outgoing circuits disconnected ? I've had connected N-E faults stop the test button working before.

 

[pc1966]

Was the test button function tested with outgoing circuits disconnected ? I've had connected N-E faults stop the test button working before.

That is an interesting point, the N-E background current could be opposite to the test button's current, not enough to trip frequencly itself, but enough to block the test!

But I would expect the MTF test to show that as failure at 'In' (similar to button) but pass at '5In' (where plenty of current to oppose the N-E fault)?

 

[Dartlec]

Was the test button function tested with outgoing circuits disconnected ? I've had connected N-E faults stop the test button working before.

I'm fairly sure i did yes, though now this thread has me doubting myself - its possible I did it with lives disconnected (via mcb) but not neutrals. Only one circuit in this case, kitchen sockets - and washing machine socket was not accessible.

I have run into cases before where the test button won't work with loads connected. (I believe some washing machines can cause strange things to happen?) so I normally ensure that all circuits are off when I test the button.

Though that then begs a further question - should the notice to press the test button add that it should be tested with all loads disconnected? If the test button doesn't work with loads connected then surely we're back to a potential C2, even if it works once they are disconnected??

 

[pc1966]

I suspect all cases of "test button not working" should be investigated.

Usually leakage L-E is going to be pretty much in-phase with the internal test button so if anything would make it more sensitive to trip, but as already mentioned a N-E fault could cause odd behaviour without always tripping. Normally though you see other loads going on/off causing a spurious trip in that case.

One reason I like the Wylex/Crabtree compact RCBO is the isolation of load L & N when off so it is simple to test for leakage without pulling out wires, etc.

 

[magnoliafan89]

Meter first, test button last, this is because if you have a sticky or slow rcd, the test button could free it up before you test, and you would never know that there was an inherent problem. That's what I was taught anyway

Interesting. I was taught press test button reset test with meter and then when done with thay just check meter hasnt broken it so press test button again

 

[Welchyboy1]

to save all the faff of paperwork, I'd replace both the RCD and the associated MCB with,say, BG devices. cost about £20. Then it would not be mix & match.

Thats exactly what i would of done, your effectively only using the LAP housing then
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I would C3 probably

Whats the rest of the install like ?

 

[telectrix]

Thats exactly what i would of done, your effectively only using the LAP housing then

a box is a box. when i shuffle this mortal coil, i don't care if they put me in a £500 coffin with velvet lining, or a plain box made from an old Ikea wardrobe. both will burn at a similar rate.

 

[Dartlec]

a box is a box. when i shuffle this mortal coil, i don't care if they put me in a £500 coffin with velvet lining, or a plain box made from an old Ikea wardrobe. both will burn at a similar rate.

What about an 18th edition coffin though, that would hopefully burn a little slower....

 

[Pauls0212]

I had this on a recent eicr, and was about to swap out the rcd until I tried the button with a screwdriver and it tripped, must have been some dust in the way and my fat fingers couldnt press it in hard enough. After the trip with screwy my fingers worked it, must have pressed it about 20 times during the eicr as i didnt trust it., but all fine now. I also retested about 5 times on auto to make sure.

 

[Dartlec]

I would C3 probably

Whats the rest of the install like ?

Ironically the rest of the install while a lot older was the easiest EICR I've had for a while.

The main CU is one of the Wylex skeleton boards in a built in meter cupboard from 70s or 80s(?) with the nasty plastic front that you have to wriggle out, Type 2 MCBs and a 100mA RCD.

Last time I checked there is no easy direct replacement for them - though a full external replacement would definitely be the best option. However, nothing there that earned less than a C3 (only 3 sockets in 2 upstairs bedrooms, 8 lights in the whole house and a connected but unused immersion and oven feed)