Will this old consumer unit pose any issues with an upcoming EICR?

Neptune · Mar 22, 2021

I've had invaluable advice from this forum in relation to EICR's and clarifying my understanding that just because the consumer unit is "old", it does not need to be replaced. Since then, I had the EICR carried out at my rental property. This went to plan.

I am now scheduling my next EICR on a separate property and this has an even older Consumer Unit but everything works and seems safe e.g. no cracked fittings or exposed cables from my pre-inspection checks.

My question: will this type of Consumer Unit be okay to produce a satisfactory EICR?

Thanks in advance.

pc1966 · Apr 24, 2021

Soi disant said:
No.

The issue is not the failure of Type AC devices to trip with a DC problem. The issue is that they won't trip with any problem if there is a DC component. Which could be always present and not a fault. Just like the way that loop testers use DC to saturate the RCD coil to stop it tripping.

Yes, an A/AC RCBO may not detect the DC, but if that persists for more than the 100ms or whatever for the B delay incomer then the incomer disconnects everything.

So AC-ish fault the RCBO goes and you get single circuit going off.

Sneaky DC fault not tripping the RCBO and it all goes off.

Not ideal, but at a few £100 for type B RCDs it would be an option, just like 30 years ago...

Soi disant · Apr 24, 2021

nicebutdim said:
You originally stated that the decline in RCBO prices was now reversing, which is patently untrue.

No, what I said was the trend for all-RCBO boards to be declining in price is reversing.

nicebutdim said:
Comparing apples with oranges (in the form of different types of RCBO) does not make this any less incorrect.

It isn't incorrect. If oranges cost more than apples, and your fruit bowl now needs oranges as well as apples then your fruit bowl is going to cost more.

nicebutdim said:
Type A RCBOs have dropped sharply in price and Type B & F are also dropping in price, albeit much more slowly due to lower demand.

They may be dropping in price, but the requirement to put them into CUs (Type Fs anyway - I'm not sure that Type Bs would ever be needed) means that the decining price trend for all-RCBO boards has reversed. The relative cost of multiple RCBOs vs 1 RCCB and multiple MCBs is like it was with Type AC devices when RCBOs started being used.

Soi disant · Apr 24, 2021

pc1966 said:
The issue with VSD, PV panels, EV batteries, etc, is they power thing with smooth(ish) DC, so when it leaks it is leaking DC

But is it leaking it because of an insulation fault, or because that's just what it does when it is working as designed?

Soi disant · Apr 24, 2021

pc1966 said:
So AC-ish fault the RCBO goes and you get single circuit going off.

Not if that RCBO has been "blinded" by the presence of DC earth leakage.

DPG · Apr 24, 2021

Soi disant said:
No, what I said was the trend for all-RCBO boards to be declining in price is reversing.

It isn't incorrect. If oranges cost more than apples, and your fruit bowl now needs oranges as well as apples then your fruit bowl is going to cost more.

They may be dropping in price, but the requirement to put them into CUs (Type Fs anyway - I'm not sure that Type Bs would ever be needed) means that the decining price trend for all-RCBO boards has reversed. The relative cost of multiple RCBOs vs 1 RCCB and multiple MCBs is like it was with Type AC devices when RCBOs started being used.

I still can't work you out Soi. I reckon another two porters and I'll have you sussed though.

pc1966 · Apr 24, 2021

Soi disant said:
But is it leaking it because of an insulation fault, or because that's just what it does when it is working as designed?

Generally anything measuring less than 1M L+N to E or so at 500V would be condemned as faulty by usual fixed wiring or PAT criteia, so you would only expect to see any significant leak "by design" in specialised cases (that don't just plug in via a 13A socket).

Soi disant · Apr 24, 2021

DPG said:
I still can't work you out Soi. I reckon another two porters and I'll have you sussed though.

There's not really anything to work out or suss, though.

Neptune · Apr 26, 2021

Dave OCD said:
Pete

Despite agreeing with you that a complete new satisfactory EICR isn't stipulated in the legislation I'm finding that Letting Agents ask for it , they don't grasp this properly and it's easier to just do it I find, after all you already have all the test results.

The electrician will provide this as part of the board replacement.

Neptune · Apr 26, 2021

nicebutdim said:
This is undoubtedly true but, from a customer's perspective, one circuit out is always going to be much less inconvenient than six - even if it only happens once in 10 years.

I've dealt with a total of two RCD tripping incidents at home. One was caused by an oven element failing and caused almost no inconvenience. The other incident involved repeated trips, which caused the loss of all hot water and I couldn't get a competent electrician to investigate, before finally fixing the problem myself.

Incidentally, it was the latter issue that spurred me (no pun intended) towards the idea of trying to retrain in the industry.

Why is this cited as such an inconvenience? Yes, all the MCB's controlled by that RCD will initially trip but wouldn't you then switch them back on one-by-one to locate the faulty circuit and then just leave that single one out of action until the fault is fixed?

nicebutdim · Apr 26, 2021

Neptune said:
Why is this cited as such an inconvenience? Yes, all the MCB's controlled by that RCD will initially trip but wouldn't you then switch them back on one-by-one to locate the faulty circuit and then just leave that single one out of action until the fault is fixed?

For the very reason I stated in that post:

Repeated trips when a fault can not be easily identified, causing the loss of half the circuits each time.

This isn't something the average household will experience often, but the hassle caused by irate tenants in such an eventuality might lead to a landlord to questioning the real value of that £120 saving.

Soi disant · Apr 26, 2021

Neptune said:
wouldn't you then switch them back on one-by-one to locate the faulty circuit and then just leave that single one out of action until the fault is fixed?

And if it's a N-E fault, and like 99.999999% of the time you've only got SP MCBs?

Neptune · Apr 26, 2021

Soi disant said:
And if it's a N-E fault, and like 99.999999% of the time you've only got SP MCBs?

Sorry, what's a "SP"?

DPG · Apr 26, 2021

Neptune said:
Sorry, what's a "SP"?

Single pole, ie the neutral is not disconnected when a fault occurs.

loz2754 · Apr 26, 2021

Neptune said:
The electrician will provide this as part of the board replacement.

Maybe, if the electrician who did the EICR is the same one doing the board replacement.
But no electrician will provide an EICR for a whole installation if he's only there to change the board, and didn't do the original EICR.

Neptune · May 5, 2021

UPDATE: The consumer unit was replaced this week. I am waiting a new EICR that was completed as part of this. Here is a picture of the finished article and I would appreciate your feedback.
The electrician said that the gap was due to the difference in size of consumer units and I would need to make that good. I assume that is normal practice.
Can I please have some suggestions on how I can finish that off please?

Thanks again.

UNG · May 5, 2021

Remove the yellow label that says "Remove after installation"?

westward10 · May 5, 2021

Have they filled those entry grommets with silicone, nasty.

timhoward · May 5, 2021

Neptune said:
UPDATE: The consumer unit was replaced this week. I am waiting a new EICR that was completed as part of this. Here is a picture of the finished article and I would appreciate your feedback.

Main thing is it's safe. And if a fellow sparks has a silicone fetish who am I to judge?!

Neptune said:
Can I please have some suggestions on how I can finish that off please?

Basically construct something with wood to cover it.
What comes to mind is a batten on the top of the boxing lid (carefully attached to miss cables and so the lid is still removeable) and a bit of hardboard attached in turn to that extending up in front of cables.
OR two triangle side pieces screwed to sides and a bit of hardboard on the front of them.

Mike Johnson · May 5, 2021

Don't know if these are available in the UK, but Hager do make them as well: https://www.leroymerlin.fr/produits...ment-legrand-h-27xl-25xp-6-5-cm-70564004.html

MrPupsi · May 6, 2021

Why people silicone when you can get the proper membrane grommets is beyond me, that looks horrible to me.
Would love to see underneath that cover.

Neptune · May 6, 2021

timhoward said:
Main thing is it's safe. And if a fellow sparks has a silicone fetish who am I to judge?!

Basically construct something with wood to cover it.
What comes to mind is a batten on the top of the boxing lid (carefully attached to miss cables and so the lid is still removeable) and a bit of hardboard attached in turn to that extending up in front of cables.
OR two triangle side pieces screwed to sides and a bit of hardboard on the front of them.

I think the triangle approach will be necessary as those cables especially the main cable is not level with the current boxing. This extra boxing will need to kick out in some way.

Mike Johnson · May 6, 2021

MrPupsi said:
Why people silicone when you can get the proper membrane grommets is beyond me, that looks horrible to me.
Would love to see underneath that cover.

The question has to be asked, if membrane grommets are the proper thing why are they not supplied with the CU.

Neptune said:
I think the triangle approach will be necessary as those cables especially the main cable is not level with the current boxing. This extra boxing will need to kick out in some way.

https://www.leroymerlin.fr/produits/electricite-domotique/rallonge-multiprise-enrouleur-et-cable-electrique/moulure-goulotte-et-plinthe/jonction-gaine-technique-de-logement-gtl-lexman-h-32-x-l-33-5-x-p-13-5-cm-69839882.html

DPG · May 6, 2021

Mike Johnson said:
The question has to be asked, if membrane grommets are the proper thing why are they not supplied with the CU.

See Post 119.

Depends what you need to use though. Compression glands, membrane grommets, SWA glands. Or maybe none if all entering from the back. They can't really include a full pack of every type and size with every consumer unit

Mike Johnson · May 6, 2021

True, but isn't a membrane grommet the most common?

DPG · May 6, 2021

Mike Johnson said:
True, but isn't a membrane grommet the most common?

Must admit, it wouldn't cost them much just to chuck a handful in.

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