Max on a DB

[skystorm]

Hi all
can some one remind me how do i work out the max power i can put on to a distribution board in a house and also in a factory
is it add all the RCD and divived it by 100ma on the house Thanks

 

[Spudnik]

Re: Max on a CB

Umm, a CB?

 

[Guest123]

Re: Max on a CB

Max what???

 

[DPG]

Re: Max on a CB

be interesting seeing where this thread goes. think i'll keep an eye on this one !

 

[Guest123]

Re: Max on a CB

I can only assume you mean maximum demand and diversity???

 

[skystorm]

Re: Max on a CB

yes been a long week thanks

 

[Guest123]

Re: Max on a CB

Ok, diversity is as follows:

Lighting - 66% of total current demand for each circuit
Power - 100% of the first ring circuit + 40% of all other circuits
Cooker - 10A + 30% of remaing rated current + 5% if the CCU has a socket outlet
Shower - No diversity allowable
Instantaneous water heater - 100% of largest heater + 100% of second largest + 25% of of any others
Thermostatically controlled water heater - No diversity allowable
Underfloor heating - No diversity allowable


As a rule of thumb if you total all the circuit breakers (not RCD's) in the consumer unit and multiply by 0.4 you will come up with an rough total of max load.

 

[skystorm]

Re: Max on a CB

Thanks Lennytheloon

 

[Notsosmart]

Re: Max on a CB

Ok, diversity is as follows:

As a rule of thumb if you total all the circuit breakers (not RCD's) in the consumer unit and multiply by 0.4 you will come up with an rough total of max load.

I've just worked out the Max CB (sic) on my own personal blackpool illuminations ( I have teenagers) & need 111Amps! ; No wonder I get letters of thanks from the chairman of E-on. lol

 

[scotsparky]

Lenny the rule inheard in Max of Largest load and 40% on rest

 

[daver]

What do you put for smoke alarms. Cannot find what small load these would be.

And Emergency lighting with the 16W 2D bulbs, what are these with control gear

Cheers

Dave

 

[scotsparky]

daver in a house the smoke alarms are possibly of a lighting circuit or if they are wired alone the load is very small just checked my alarms 0.03a 30ma as its that low i wouldnt even factor it into the diversity calculation unless i had a huge amount 20+ sort of region.

As for the emergency lights I=p/v so 16 /230 =0.06 amps depends how many you have wwhether you calculate it in again either linked of lighting or seperate circuit.

 

[Guest123]

Lenny the rule inheard in Max of Largest load and 40% on rest

Sorry Scot mate, bit confused by this

 

[daver]

Thanks Scot.

All on separates. I knew Smoke was nominal, it was just control gear for the 2D's

Cheers

Dave

 

[scotsparky]

Lenny if you have the "electrical installation design guide(grey iee handbook) look at page 28 for domestic installations.