Definitions relating to Consumer Units

[SDH]

Good evening folks,
Looking for some yes that is it, or, you are thinking about this wrong way type responses here please.

Doing an assignment (open book)
Being asked about the definition of a few terms and I think I have them but clarification would be appreciated:

Modules: The Module would be the MCB or RCB for example.

Ways: Would be the number of circuits that a DB can supply.

Split Load: A split load consumer unit would be one which allows multiple circuits to be protected by a single RCBO but others to not, so that in the event of a fault with a socket knocking out power to all of the sockets, provided the lighting circuits are not also on the RCBO side of the board, then the lights would stay on.

Appreciate any help on this one.

 

[telectrix]

Good evening folks,
Looking for some yes that is it, or, you are thinking about this wrong way type responses here please.

Doing an assignment (open book)
Being asked about the definition of a few terms and I think I have them but clarification would be appreciated:

Modules: The Module would be the MCB or RCB for example.

Ways: Would be the number of circuits that a DB can supply.

Split Load: A split load consumer unit would be one which allows multiple circuits to be protected by a single RCBO but others to not, so that in the event of a fault with a socket knocking out power to all of the sockets, provided the lighting circuits are not also on the RCBO side of the board, then the lights would stay on.

Appreciate any help on this one.

no. a split load board is one where the circuits are not all protected by a single RCD, but 2 RCDs. there may also be 1 or more non-RCD ways. RCBOs are a different situation, whereby each circuit is protected by it's own RCD.

 

[Kate]

Isnt module the total capacity of the db? So a 20 module db is a 14 way one. 14 ways for mcbs as 6 are taken up as standard by the 2x rcds and 1x main switch??

Split load db has 2 rcds. To spread all the circuits across so if theres a fault knocking out 1 of the rcds, there is still a combo of lighting and socket circuits energised on the other.

An RCBO covers only one circuit. It is a protective device that combines the functions of both mcb and rcd.

 

[Marvo]

Isnt module the total capacity of the db? So a 20 module db is a 14 way one. 14 ways for mcbs as 6 are taken up as standard by the 2x rcds and 1x main switch??

Not sure about the UK but where I am we describe it the other way around. A 14-way panel has room for 14 MCB's.

 

[Kate]

Yea 14way db can hold 14 mcbs. But a 20 module db IS a 14 way one.

 

[Kate]

Screwfix copy n paste.....
22-module split load insulated consumer unit. Flexible busbar. BS EN 60439-3.
100A Main Switch
1 x 80A 30mA RCD
18-Way (22-Module)

 

[telectrix]

kate. i love it when you go all technical. :49:

 

[SDH]

Thanks for the replies guys.
So a module is a space almost? An RCD taking up two modules, mcb's taking up only one?

 

[Kate]

Yes thats right SDH

 

[telectrix]

yep. a module is a space, but Main switches and RCDs take up some modules leaving you with the remaining modules being ways.

 

[Kate]

kate. i love it when you go all technical. :49:

Lol. Have an embarrassed smiley face now

 

[Marvo]

Yea 14way db can hold 14 mcbs. But a 20 module db IS a 14 way one.

Lol, I thought I was confused before but I think my sanity just got up and left completely. The module definition is something we don't really use. The way we'd describe it is if a panel was 14-way and it had 2 x RCD's mounted in it that take up 2 spaces each then there'd only be 10 ways left for MCB's. If I needed a panel for 14 MCB's and 2 x RCD's I'd need to order an 18-way panel.

There's a good possibility there might be geographical differences in some of these terms so please don't take my answers as gospel.

 

[Kate]

Wholesalers know. I always ask for say a 12way db. It was them that told me about it being an 18module.

 

[Marvo]

Screwfix copy n paste.....
22-module split load insulated consumer unit. Flexible busbar. BS EN 60439-3.
100A Main Switch
1 x 80A 30mA RCD
18-Way (22-Module)

Ahh, I think the difference is that your consumer units are bought partially populated whereas we buy naked panels and build DB's from scratch.

 

[SDH]

Ok that makes sense.
So if I was to be defining modules, then ways, then split load.
it would make sense to say. 22 modules, with three split loads, Main switch, RCD, RCD, leaving 16 ways for circuits, which would each be protected by an MCB.