A better way to replace CU?

[All Sorts]

Assuming most of you will be familiar with a typical 17th Edition consumer unit having 2x RCD's split, I'd be interested in knowing what concensus of opinion is on upgrading some of the less ancient 16th Ed split-load boards instead of replacing whole thing?

I'm thinking rather than lose half the circuits to nuisance tripping etc, wouldn't a better result come from just leaving in a single mains switch and replacing all MCB's with RCBO's (assuming board is new enough to accomodate them of course).

What say you all?

 

[AndrewMgan1976]

Seperate RCBO's is the best way to do it, but try getting the customer to pay for seperate RCBO's might be a little more difficult

 

[Phil]

yeh must admit i like the seperate and the customer would in the end but as said it`s a matter of persuading them it`s the way to go

 

[timo1]

If it helps meteor electrical sell rcbo's for about £12, which is fairly cost effective depending on how many circuits you have.

 

[ste mac]

I suppose 4 RCBO's @ £22 each = roughly price of new dual RCD board, but RCBO's are more convenient as far as tripping is concerned.

Swings and roundabouts.

 

[Mark_Burgess]

If it helps meteor electrical sell rcbo's for about £12, which is fairly cost effective depending on how many circuits you have.

I second timo1, I have fitted loads, dont let the cheapness put you off they work fine.

 

[jordachus]

I second timo1, I have fitted loads, dont let the cheapness put you off they work fine.

The only issue is with the make of the rcbo`c most manufacturers of C/U only accept protective devices of the same make

 

[brucelee]

Hi guys when fitting RCBOs do you have to use the same make as the board or is it acceptable to use another make
ie volex board single rcd split and fit wylex RCBOs if they are compatible to the unprotected side or do you have to use the same make ie volex

 

[Deleted member 9648]

Hi guys when fitting RCBOs do you have to use the same make as the board or is it acceptable to use another make
ie volex board single rcd split and fit wylex RCBOs if they are compatible to the unprotected side or do you have to use the same make ie volex

No problem as long as they fit properly ,although it might void the board manufacturers garantee.

 

[Amp David]

The only issue is with the make of the rcbo`c most manufacturers of C/U only accept protective devices of the same make

Not exactly true. There are a wide range of different CU makes that all take the same size and shape MCB/RCBO

Most 16th Edition boards will be out of any manufacturers warranty now so wouldn't reallt come into play in most situations

 

[IQ Electrical]

Hi guys when fitting RCBOs do you have to use the same make as the board or is it acceptable to use another make
ie volex board single rcd split and fit wylex RCBOs if they are compatible to the unprotected side or do you have to use the same make ie volex

It voids the criteria of BS60439-3 UK annex ZA which allows us to rely on the DNO's device for short circuit protection in domestic installations.
Assuming your measured PFC is less than the lowest rated device in the consumer unit then you're good to go!

 

[brucelee]

No problem as long as they fit properly ,although it might void the board manufacturers garantee.

cheers wirepuller
the board has been in for over 5 years just going to use it rather than replace it . there is also a old wylex fuseboard, so i am going to transfer the circuits over from thet to the volex and as there is only one RCD then i will use RCBOs on the unprotected side.
so as for the guarantee dont know how long they last is it for the life of the ccu or a limited guarantee
cheers mate

 

[brucelee]

It voids the criteria of BS60439-3 UK annex ZA which allows us to rely on the DNO's device for short circuit protection in domestic installations.
Assuming your measured PFC is less than the lowest rated device in the consumer unit then you're good to go!

Hi Iq
so as long as the prospective fault current is less than or equal to the breaking capacity if the protective device it doesnt matter on what make they are as long as they are compatible with the board

 

[IQ Electrical]

Yes, the annex was negotiated to allow the UK continued use of BS3036 fuses with SS capacities as low as 1kA.
Mathematically, a Ze of less than 0.23 Ohms would result in a PFC higher than those devices could safely interrupt.

 

[brucelee]

cheers mate
I have to remove a wylex with bs3036 and transfer the circuits over to the volex single RCD split load so will need to provide RCBOs for the unprotected side of board
and as i may need a few due to the existing wiring to the sockets being imperial and possibly the sockets are not rings then i will have to install a fair few 16a or 20a RCBOs cheers mate these will all have a breaking capacity of 6kA type B
I was going to replace both boards for a new dual rcd split but my brother wants a SWA to the shed at some point so i will need a unprotected way then i can RCD the shed
the wiring to the boards is a mess and will take some sorting to make it acceptable for assessment as i am using this for my registration with elecsa
cheers IQ