Dartlec

Arms
Doing one more of the flood of EICR today on a rented property before a tenant change, but ran into a slightly interesting case so would appreciate other people's views.

About 6.5 years ago I partially rewired the small kitchen at this property - and since the main fuseboard was a skeleton wylex cupboard job and a pain to replace, I added a small Garage CU with 80A RCD to supply the 32A MCB for the kitchen ring to comply with RCD requirements (The main fuseboard has a 100ma RCD).

Today during the EICR, the newer RCD tested perfectly using the megger, but the test button is non functional - doesn't seem to have any resistance behind it so I'm guessing has mechanically failed.

The issue then becomes what code this is noted on the EICR.

Common sense may say it's best to change it since it could be a sign of failure. However, it passed the tests with no problem and therefore functions correctly as an RCD.

A previous thread discussed a similar topic 6 years ago and most people agreed this should be a C2.

However, the ESC best practise guide states that C2 codes are for situations that aren't dangerous at the time, but "would become an immediate danger if a fault or other foreseeable event was to occur"

This is a TN-S system, and the circuit in question has a low Zs so the RCD is not required to meet tripping limits for the MCB - it is there for additional protection as required by Regs.

If this was an EICR on an older board the absence of an RCD would be no more than a C3, so it seems slightly overkill to list this as a C2 and therefore grade the whole EICR as "unsatisfactory"

My own view is somewhere around a C2.5 for cases like this, or perhaps a C2 but a "satisfactory" rating, both of which are not options based on the guidelines.

Given that we know exactly 0.05% of people press the test button, whether quarterly or bi-annually, and given that an inspection will occur after 5 years, does the non-functioning test button actually have an outcome on the "electrical safety" of the installation, which is what the EICR is for after all?

I have no idea how frequently the test buttons fail in comparison to the rest of the device, or whether one it is always indicative of a developing fault.

EICR aside, assuming that the RCD should be replaced, the further wrinkle is that it was a LAP branded board, RCD and MCB, which I believe are no longer produced, (At the time the customer wanted to save money so a LAP garage unit was the chepest option.) so replacnig just the RCD would either mean mixing and matching (which is itself usually a C3 in my book) or entirely replacing the unit.

How would other electricians deal with that part, given that it's long past supplier's warranty periods? Bite some of the cost themselves as a goodwill gesture? (Obviously not installing LAP brand goes without saying, but given MK and the current situation who knows which brands will be around in 6 years?

Final note - any one know who made LAP stuff - and whether it is still made under a different brand?
 
You make some good points. I think I would code it a 3 but qualify that with a note that it passed trip times testing and while an inoperative test button is not considered to represent a potential danger the unit should be replaced as soon as possible.
Unfortunately if a replacement RCD is not available the board will need to be replaced.
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C2. RCD has failed one of its 5 tests.
Wouldn’t mix and match. Buy cheap, buy twice.
I'm not sure you can justify such a blanket statement. Lets say an RCD was serving a surface wired immersion heater circuit which did not require additional protection and the OCPD met disconnection times. How would you justify it being potentially dangerous when an RCD which is not needed anyway failed a test?
 
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Wouldn’t mix and match. Buy cheap, buy twice.

Definitely won't buy LAP again! But clients don't always see past the quote.

And can we be sure any mcbs will still be available in 6 years? Wouldn't be surprised to see some of the firms go under in the current climate, so it's about time the industry sorted themselves out and came up with a standard.

That said, I code mix and match a C3 these days (assuming they do grip the busbar properly, else a Code 2)
 
C2. RCD has failed one of its 5 tests.

I agree that is maybe the simplest option. But it just seems a discrepancy when if the RCD were replaced with an isolation switch, then it would only be coded as a C3 (hypothetically, since that couldn't be done as new work under current regs anyway)

In this case I may well be doing some extra sockets before the next tenants move in (who happens to be the landlords son), in which case I may end up changing the entire main consumer unit anyway, which would resolve the issue.

It's more the result of the entire EICR being marked as unsatisfactory that grinds (since we all know thats all anyone looks at). This is where I'd like a C2.5 - satisfactory as long as x is done before the next inspection.
 
I agree that is maybe the simplest option. But it just seems a discrepancy when if the RCD were replaced with an isolation switch, then it would only be coded as a C3
That is not quite a fair comparison though. The RCD is expected to work and provide additional protection. Even though it is doing its job when tested using your MFT anyone in the property trying to test it using the only means they know of (the test button) will find it faulty and probably call the landlord in a bit of distress to get it fixed.

OK, I made that last bit up. How many folk actually try the test?
 
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That is not quite a fair comparison though. The RCD is expected to work and provide additional protection. Even though it is doing its job when tested using your MFT anyone in the property trying to test it using the only means they know of 9the test button) will find it faulty and probably call the landlord in a bit of distress to get it fixed.

OK, I made that last bit up. How many folk actually try the test?

A fair point. In this case, the landlord's son will be moving in and I've already made the landlord aware. (Needless to say the existing tenants had never pressed it in their 6 years).

If the work were for a letting company or I was being sub contracted I'd probably just C2 and move on.

But I'm honestly not sure if the overall situation can/should be taken into account when doing an EICR, given that the house could be sold tomorrow and if not rented then another inspection may never happen.

If it was marked as C3 but clearly noted on the cert that it should be changed within the next 6 months (which is when the RCD should in theory be 'tested' by pressing the button again), would that be considered reasonable if something were to happen in the meantime?
 
It is hard to say 'C2' when the RCD is actually functioning and the "best practice guide" offers C2 for the case:
  • The main RCD or voltage-operated earth leakage circuit-breaker on a TT system fails to operate when tested with an instrument or integral test button
Specifically that they only code C2 for a TT system where it would depend on the RCD for fault clearing. To me that is too restrictive, if you need an RCD for additional protection (in many cases that debate could run for pages here) and it is not working then it should be considered C2 as potentially dangerous.

Now while your case has a working RCD on meter testing, as pointed out above, it is faulty and without knowing why it has failed it is difficult to say you could trust it to work until the next EICR (more so when the occupant has no means of testing).

So personally I would have to say C2 as it cannot be trusted to provide the protection expected of it, though I can see why it could be legitimately argued for C3.
 
It's more the result of the entire EICR being marked as unsatisfactory that grinds (since we all know thats all anyone looks at). This is where I'd like a C2.5 - satisfactory as long as x is done before the next inspection.

You can't put conditions on a satisfactory result like that, it would be like saying 'i'll put down satisfactory if you give me an extra £200'

Yes the overall result is unsatisfactory, that is because you have identified that a device which is intended to save a human life in the event of a fault is not operating correctly.
 
I've slightly amended my view on this, I cant see it as potentially dangerous but it's a faulty device and needs changing, so I think a code 2 is probably justified to make sure it is changed
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but if it doesn't say LAP on the tin, who's to know? you could say it's akin to fitting wago connectors in a wiska box.
I get what you are saying but all the other devices in the board will be LAP, however you look at it there will be two brands in the DB.
Daft just for a technicality though, we both know if it fits right it'll be fine!
 
Would be in a lap enclosure though, still mix and match!
I think the "mix and match" issue applies (technically at least) when you have a busbar arrangement as in a typical CU. There you have to make sure the busbar is properly entering and being clamped by the MCB, and you get a lot of variations on that.

If it is simply a RCD enclosure on a circuit already fed by a MCB from the main CU it would have no need for a busbar, just wires in and out, so I see no technical reason to complain.

But given the low cost of a pre-populated garage CU it would be worth just replacing the whole thing (assuming wires are not stretched out to limits and difficult to accommodate the slightly different new one).
 
I've slightly amended my view on this, I cant see it as potentially dangerous but it's a faulty device and needs changing, so I think a code 2 is probably justified to make sure it is changed
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I get what you are saying but all the other devices in the board will be LAP, however you look at it there will be two brands in the DB.
Daft just for a technicality though, we both know if it fits right it'll be fine!
how can there be 2 brands when both RCD and MCB are replaced? the remaining is just an enclosure.
 
how can there be 2 brands when both RCD and MCB are replaced? the remaining is just an enclosure.
Indeed, sorry I'd forgotten it was a 1 way DB and not a dual RCD main board or whatever.
However it could be argued that it's still non compliant with the enclosure.
That said the cost of a small DB is minimal so just change the whole thing and you know it's right.
 
Indeed, sorry I'd forgotten it was a 1 way DB and not a dual RCD main board or whatever.
However it could be argued that it's still non compliant with the enclosure.
That said the cost of a small DB is minimal so just change the whole thing and you know it's right.
but if it doesn't say LAP on the tin, who's to know? you could say it's akin to fitting wago connectors in a wiska box.

The enclosure does actually say LAP, so if you were being exact putting another brand in there would be mix and match. As I understand it, the main reason for using all the same brand is to maintain the 16kA capacity rating based on the type testing by the manufacturer. Whether LAP or whoever made this actually did that is another matter of course...

However, replacing the entire unit would presumably require an 18th edition installation (Not just a 'direct replacement' as if effects the source of the installation), so metal box, new EIC, new testing of the circuit, Part P notification etc - i.e. not a 10 minute job, though not a huge PITA in this case.

I can probably say safely that the cost of a SPD is not justified, let alone an AFDD :)

Any experience of the small dbs for ease of use with cabling etc? Wylex or Crabtree are most likely to be around in 5 years I guess.

Thanks for all the replies. Replacing it is the correct option of course, though that's still in my mind a separate issue from the EICR.

When others have failed an EICR and then carried out remedial work, have you re-issued the EICR? Technically the recent landlord law allows the unsatisfactory cert + confirmation of the required work (MWC or EIC included presumably) to be taken together as proof of electrical safety. However, explaining that to anyone who ever looks at the certificicate is likely to be a pain, especially when it's potential tenants.
 

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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
 
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?
 
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 :rolleyes:.

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...
 

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.
 
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?
 
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!
 
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!
 
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)?
 
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??
 
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.
 
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
 
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 ?
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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.
 
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.
 
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)
 

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Dartlec

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EICR Code for working RCD with non-functioning test button
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