What is maximum current of the mains?

[treezleef]

Hi,
What is th emaximum current draw allowable from the mains for...

UK domestic single phase
Light industrial single phase
Light industrial 3 phase

If there are different levels, then please advise.

Basically i suppose what i am asking is what current does the wiring have to be rated for, and what is the breakers tripping points.
Am i right in saying that single phase in UK for domestic is either on a 16A circuit, or a 32A circuit.
And that its the same for light industrial.

And the industrial 3 phase is the same...but that current in each phase?

 

[James]

100A is a normal domestic supply in the uk
same for light industrial both single and 3 phase

however, anything is possible if you ask and pay for it.
I have never come across a supply for industrial that was over 400A per phase.
any higher than that and generally they will push you to a High voltage supply instead.

 

[timhoward]

The wiring is always rated according to the protective device (fuse / breaker) before it.
Domestic properties tend to have 60,80 or 100 amp supplier fuses.
Industrial / 3 phase can be considerably larger.

Am i right in saying that single phase in UK for domestic is either on a 16A circuit, or a 32A circuit.

It's common to have circuits ranging from 6 amp circuits for lighting to 40 amp circuits for an electric shower. The wiring would be different sizes for each.

 

[treezleef]

Thanks, and please advise, if you have a 3 phase supply 230VAC, and each phase is 60A rated, then you can supply a max power of 3 * 60A * 230V = 41.4kW?

 

[Julie.]

Thanks, and please advise, if you have a 3 phase supply 230VAC, and each phase is 60A rated, then you can supply a max power of 3 * 60A * 230V = 41.4kW?

Sort of.

There is a thing with alternating current called power factor.

If your load is resistive, such as an immersion heater, then yes 41.4kW.

If your load is a motor or some other things, although the amps x volts = 41.4kVA (kilo volts x amps) the actual power may only be 80% of this so 33kW.

This is a rather technical aspect of ac system we use.