Consumer unit question?

[J_c9sh]

Hi all,

Just a quick one from me,

Is there a set regulation on the maximum amount of ways on a consumer unit for a single phase supply I.e for a medium to large sized house

Thanks

 

[not clever]

No, but a good idea to leave a couple of spare ways.

 

[1shortcircuit]

No there is not. Any particular concern you have?

 

[J_c9sh]

Yeah, rewriting an extension on a house and I will be using the last 2 ways of an 16 way comsumer unit for lighting and power, just thought it was far too much for a house and there will be no spare ways left
?

Thanks

 

[1shortcircuit]

Not your problem really. You cannot expect to allow for future proofing on every visit Although if you are that concern you could always fit an additional 2 way board and protect your circuits with RCBO's.

What is the maximum demand of the installation you are working on?

 

[J_c9sh]

The board is already fitted with RCBO's which is good, I'm abit slow sometimes but when u say maximum demand, is that all breakers added together as if everything would be in use

 

[Plonker 3]

No maximum demand is the maximum amount of current the property is likely to use. Most domestic dwellings will never draw more than 30 amps at any one time.

Sent from my GT-I9300 using Tapatalk 2

 

[not clever]

No your not slow, you just have not read the osg or BGB................both will inform you of max demand & how to work it out....

Electrical Trainee

 

[Plonker 3]

Common sense will give a better idea of maximim demand rather than any book as every installation is different.

Sent from my GT-I9300 using Tapatalk 2

 

[1shortcircuit]

The board is already fitted with RCBO's which is good, I'm abit slow sometimes but when u say maximum demand, is that all breakers added together as if everything would be in use

The maximum demand is what you need to determine when designing or adding an additional load to a new/current installation. If a 60A main fuse is provided by the DNO then you need to prove by calculation that your additional load/s will not be detrimental to the operation of the entire installation:thumbsup

 

[J_c9sh]

Thanks for that, if I was to install another 6 way comsumer, do u reckon that would be ok then

 

[1shortcircuit]

No your not slow, you just have not read the osg or BGB................both will inform you of max demand & how to work it out....

Electrical Trainee

Common sense will give a better idea of maximim demand rather than any book as every installation is different.

Sent from my GT-I9300 using Tapatalk 2

This in my opinion is where the clamp meter is worth it's weight in gold. Turn everything on and see what is being pulled.

I

 

[Plonker 3]

As has been said. What power do they already draw. What size is the main fuse. What circuits you going to be wiring?

Only you know this and need to make a judgement based on that information.

Sent from my GT-I9300 using Tapatalk 2

 

[not clever]

I agree.
But when you get

maximum demand, is that all breakers added together as if everything would be in use

​

You have to think maybe just maybe they have no grasp the basics of max demand & should start by taking a look at the books?
​

 

[1shortcircuit]

Thanks for that, if I was to install another 6 way comsumer, do u reckon that would be ok then

Based on the information you have provided? Erm, safest bet for me is to say no as I have not seen the installation or know any of the other details. MAX DEMAND NEEDS to be calculated before any additional circuits are added. Only you can decide if you think this is an acceptable option as it is your name being signed to the work.

:thumbsup