Replacing consumer unit

[Tomdhu]

Currently our CU is a plastic unit fitted around 2004 and it has 12 MCBs of which 5 have RCD protection.

In terms of hours, how long would it take and how much roughly would it cost ( location London SE22 ) to replace this with a modern 16 way unit fitted with :-
A) SPD
B) Transformer for 12v door bell and video intercom
C) 12 transformer to supply 5 (7 watt) LED down lights.

Finally, which brand of CU would you recommend?

 

[EricMark]

A consumer unit can only contain items it was type tested with, so likely the doorbell transformer and the down light transformer will not be permitted in a new consumer unit, in fact should not be in the old one.

I live in Wales, so no idea of labour charges in London, but labour will cost more than the consumer unit, so it makes sense to fit all RCBO's type A, as to AFDD that's a matter for discussion as to date as far as I am aware, there is no way to test if a fault is the device or a real fault, we all have testers for RCD/RCBO but the AFDD we are in the lap of the gods.

Next is risk, talking about risk of something going wrong. When I had a new consumer unit, I agreed to sort out any problems with the installation, so no EICR was done, and I was left with a problem on the lighting due to borrowed neutral, which I corrected, but with any job, not only electrical, they may highlight faults which no one realised were there.

So the safe method is an EICR first, then no surprises, but after completed the electrician has to do it all a second time, so one could take the attitude, if it needs fixing, it needs fixing, and I don't need to know cost before anything is started, or one may feel one needs to know exactly what you need to spend before you start.

Basic either you pay by the hour, risk is yours, or pay by the job, risk is the electricians. When I needed more labour I always paid by the hour, not by the job, that why I was employed as an electrical engineer. But to pay by the job, the electrician needs to visit first, and work out how long it will likely take him. Can't work that out on a forum.

 

[mainline]

A consumer unit can only contain items it was type tested with, so likely the doorbell transformer and the down light transformer will not be permitted in a new consumer unit, in fact should not be in the old one.

CU bell transformers are available.

 

[baldelectrician]

I use Hager, decent quality and has the bonus of (based on past experience) the parts made now fit the consumer units from years ago

Last year I was able to replace a cooker circuit on a 1990's Hager board and install a new RCBO to bring the circuit up to todays standards

The light transformer will need to go in a seperate enclosure

 

[HappyHippyDad]

Hagar always seems to be mentioned as the best choice. I am perfectly happy using Fusebox or BG.

As for cost. Could be £600 without any problems and cheap board. Likely to be around £800. Could easily be £1000. Might be many thousands if the electrician discovers many faults. I think I've covered myself adequately there. Ps.. My costs are just for a new board, nothing to do with transformers.

 

[Tomdhu]

I use Hager, decent quality and has the bonus of (based on past experience) the parts made now fit the consumer units from years ago

Last year I was able to replace a cooker circuit on a 1990's Hager board and install a new RCBO to bring the circuit up to todays standards

The light transformer will need to go in a seperate enclosure

Thanks for your comments. Hager does indeed get god reviews with the exception of their AFDD. Dave Savery did some pretty convincing tests on this rig and they turned out to be very poor at detecting arcing.

 

[mainline]

David’s arc chamber caused so much inteference that the outcome cannot be said to be convincing.

I’ve installed quite a few Bg boards but have had a few faults with faulty mcbs and rcds never had a problem with the fusebox ones.

 

[EricMark]

Some makes of consumer units do have bell transformers, but if a Fusebox CU it must be a FB transformer.

I found the price of one item, can change the whole price of the board by a huge amount, the SPD can vary in price so much.

Also down to the electrician doing the work, my boss had an account with one wholesale outlet, and if they did not have what I wanted, then the price jumped, and the last thing you want to do is provide parts yourself, if something goes wrong, you want to be able to blame it on one firm.

The argument the device was faulty v your electrician damaged it. Is one you don't want, if something fails, you want to be going to one guy, not having to argue as to if supplier should pay for replacement or the electrician who fitted it.

Hopefully nothing will go wrong, but still better to let the electrician source materials.

 

[Teddy Lop]

Thanks for your comments. Hager does indeed get god reviews with the exception of their AFDD. Dave Savery did some pretty convincing tests on this rig and they turned out to be very poor at detecting arcing.

I'm not familiar with the testing you reference but I'd be surprised, I've always found hagar to be some of the best out there, both in terms of construction (many manufacturers devices are a little more sloppy in tolerances and have a tendency to twist when tightened onto busbars) and also when testing trip RCD times (it's not unusual with hagar RCBO's to record a list of trip times that read something like 16.9, 16.8, 17.1, 16.9, 17.5 etc which might be inconsequential but such consistency just feels so right, when other makes will be giving readings all over the shop)

As for AFDD we don't/cant test so it'd be interested to know what tests people are using and how they relate to design brief, real world faults and also nuisance mitigation; the early AFDD's were by all accounts terrible for the latter, so more sensitive doesn't equal better - there's a reason we don't use 10mA RCD's domestically.

 

[Tomdhu]

I'm not familiar with the testing you reference but I'd be surprised, I've always found hagar to be some of the best out there, both in terms of construction (many manufacturers devices are a little more sloppy in tolerances and have a tendency to twist when tightened onto busbars) and also when testing trip RCD times (it's not unusual with hagar RCBO's to record a list of trip times that read something like 16.9, 16.8, 17.1, 16.9, 17.5 etc which might be inconsequential but such consistency just feels so right, when other makes will be giving readings all over the shop)

As for AFDD we don't/cant test so it'd be interested to know what tests people are using and how they relate to design brief, real world faults and also nuisance mitigation; the early AFDD's were by all accounts terrible for the latter, so more sensitive doesn't equal better - there's a reason we don't use 10mA RCD's domestically.

Here's the link to David Savery's tests:- Hager AFDD testing

 

[Teddy Lop]

Here's the link to David Savery's tests:- Hager AFDD testing

Thanks but - am I supposed to take that seriously?