selecting consumer units

[--tom]

Q1 what size consumer unit for average semi?
Q2 say i require 20 fuseways, what is available?
Q3 say i require 200A c/u, what steps do i have to take ref the electric board?
Q4 how would i determine the ampage of an in-situ c/u?

 

[ban-all-sheds]

A1 - 10-12 way, on average, plus a separate one for shower.
A2 - probably not much in the domestic-stylie ranges. You could use 2 smaller ones, one with RCD, one without.
A3 - get in touch with them
A4 - it'll be written on the main incomer

 

[securespark]

A1 - 10-12 way, on average, plus a separate one for shower.

Hey???

 

[securespark]

MK do insulated units up to 21 modules (less incomers) but you can stack two together (sizes 12, 16 and 21 module)

Don't forget that 21 modules (for example) means space for 21 modules-the number of "ways" depends upon how many incoming devices you are using (ie 21 module with 100A incomer=19 ways)

Personally, I would include the shower in the main unit.

A4 Or in the case of an older style unit, on the front cover.

 

[il78]

Maybe an idea to go for two boards, one being RCD protected.....thats only if you think you need something of that size........

 

[plugwash]

the largest Cu mk make is 21 module if you fit this out a split it will leave room for 17 mcbs

beyond that i think 2 CUs with henlys (one with rcd one without) is the best way to do

 

[securespark]

plug already said that...

Plus as I already said

You can get a linking kit and put 2 MK units together...no need for henleys

 

[il78]

Just tryin to take your credit

 

[securespark]

Credit? I'm broke. All these kids.........

 

[il78]

You only have yourself to blame.......

 

[securespark]

This is very true!

As was said in Monty Python's "The Meaning Of Life"

".....because he refuses to wear a little rubber thing on the end of his John Thomas......"

 

[--tom]

thank you all for your replies.
Q1 what is an incomer?the mains supply from the meter?
Q2 what precisely is a module as distinct from a fuseway?
Q3 are there any detailed pics of a c/u with annotations?

 

[securespark]

I'd say you have a pretty inapproachable lecturer if you don't know the answers to these questions......


1. The 100A DP isolating switch of a CU.

2. Not sure of the exact dimension (think it is 18mm, but you could measure it) but a module is the width of a standard mcb.A unit being 21 modules big means it has space for 21 individual modules. Everything that fits into a CU is described as being "x modules wide", so an mcb is one module wide, a DP incomer and rcd's are two modules wide, CH programmers are one or two depending on the design, bell transformers are 2 and time switches are three.

The term fuseway is really only used for fuseboxes as opposed to units employing mcb's. However, the term "way" is still used to denote how many mcb's a CU will accept.

3. Try the net.

 

[plugwash]

note that some brands of rcd (get springs to mind) are 3 modules wide not 2

 

[Big_Spark]

note that some brands of rcd (get springs to mind) are 3 modules wide not 2

Plug, if they are single phase they will either be 1 or 2 modules wide, if they are 3 modules wide then they will be a three phase unit.