Maximum demand calculation

It may help to consider how much floor area are you serving - there is a limit to the number of kW anyone will dissipate in a small space for very long without overheating and turning things off - the 32A per 100m2 rule may be more realistic for domestic regardless of how many circuits  it is divided over.

is the 2A the real max load on the lights? - if it is LED or even CFL, you get a lot of lighting for an average current of an amp. 

Mike

mapj1: 
 

It may help to consider how much floor area are you serving - there is a limit to the number of kW anyone will dissipate in a small space for very long without overheating and turning things off - the 32A per 100m2 rule may be more realistic for domestic regardless of how many circuits  it is divided over.

 

is the 2A the real max load on the lights? - if it is LED or even CFL, you get a lot of lighting for an average current of an amp. 

Mike

The house is 150m2. That would be 48A for socket outlets as a maximum demand calculation - that’s 11kw of power from socket outlets, seems a bit high to me? 

The loading on the lighting circuits would be around 1amp. The customer wants to add an air source heat pump onto the 100A supply and I need to calculate the theoretical maximum. The heat pump draws a maximum of 28A when less than 5 degrees outside. 

I need to calculate the theological maximum.

Better start praying then!

Regards

GOD

perspicacious: 
 

I need to calculate the theological maximum.

Better start praying then!

Regards

GOD

Ha! 

Corrected! ;-) 

onto the 100A supply 

What colour is the cut-out? Black or grey?

Regards

BOD

perspicacious: 
 

onto the 100A supply 

What colour is the cut-out? Black or grey?

Regards

BOD

It’s grey, and is marked as “100A fuse fitted” 

The heat pump draws a maximum of 28A

About £1.20 an hour then.

Regards

BOD

It’s grey, and is marked as “100A fuse fitted” 

That's a rarity. Some meters, particularly Smart meters when installed require the meter fitter to replace with an 80 A cut-out fuse.

Regards

BED (it's been a long day for this old chap!)

The problem is with a 40A EV charger and a 65a cooker, there really  is not a lot of slack. I presume the place is heated by gas or oil, or at least not electricity, but the cooker is not gas so maybe not. If the sockets, and on the 100m2 rule of thumb, yes it could be seen as 40 odd amps worth of final circuits,  but of course that can be further diversified, (for a safe example 100 % of first 10 A +50% of  current demand in excess of 10A is the generic OSG way - that gives 10A+15A ) so more like 25A for all the socket circuits  into the full sum.

Even so it will be hard to get it to add up to be much less than the full 100A, but we know that is not very realistic either, in the long term electricity bills see to the consumption being curtailed.

Mike.

mapj1: 
 

The problem is with a 40A EV charger and a 65a cooker, there really  is not a lot of slack. I presume the place is heated by gas or oil, or at least not electricity, but the cooker is not gas so maybe not. If the sockets, and on the 100m2 rule of thumb, yes it could be seen as 40 odd amps worth of final circuits,  but of course that can be further diversified, (for a safe example 100 % of first 10 A +50% of  current demand in excess of 10A is the generic OSG way - that gives 10A+15A ) so more like 25A for all the socket circuits  into the full sum.

Even so it will be hard to get it to add up to be much less than the full 100A, but we know that is not very realistic either, in the long term electricity bills see to the consumption being curtailed.

Mike.

Thanks. The cooker is 27A after diversity, so this is OK.

The properly is gas but the plan is to add a hybrid heat pump for reduced gas consumption. 

If i assume 25A for sockets this seems realistic.