All electric flat require a 3phase supply

[Housebasher87]

Hi! Currently doing a job that they have decided against getting gas meters and going all electric.
Electric boiler 9.5kw
2x shower 9.5kw
Hob say 6.5kw
2x 32a ringmains
2x 6a lighting circuits
I understand they have had a 13Kva supply installed.
Obviously this will not be enough to run all that?
Going forward on this would it be better to ring supplier for an upgrade? (3phase or 100a?)
Or if i loose a shower would this then be ok?

 

[littlespark]

With a decent electric boiler, you won’t need electric showers. Just thermostatic valves and maybe a pump for each.

Wet heating system off the boiler?

2 showers suggests a family home… is 2 rings of sockets enough? Maybe a third just for kitchen?

 

[Housebasher87]

With a decent electric boiler, you won’t need electric showers. Just thermostatic valves and maybe a pump for each.

Wet heating system off the boiler?

2 showers suggests a family home… is 2 rings of sockets enough? Maybe a third just for kitchen?

It’s just a flat. 3x bedroom, open plan lounge/kitchen. On suit in one of bedrooms. I’v not really dealt with many electric boilers tbh. They want under floor heating ran off it and a zone for each room.

 

[James]

I think now is the time to get the electrician on board with the planning stages.

 

[SparkySy]

i would ditch the two electric showers as @littlespark suggests and put either thermostatic showers off the electric boiler or maybe a good size pressurized cylinder (megaflow or likes) with immersion heaters in there if there is room for it.
The lighting circuits will be minimal draw with everything being LED these days and apart from the usual high load appliances the ring mains probably will rarely draw more than 16a most of the time (unless they have teenagers)
Maybe get a slightly lower kw hob like 5kw induction?!

Depending on the customer and their consumption you may just be ok with the above!

I did some work in a 3 bed log cabin a while back that was on a 50a type c mcb (already installed by others) that on paper should have really been on a bigger supply, speaking with the owner he said it had never tripped out in the 10 years they had been there.
Apart from the oil boiler was all electric with a 8.5kw shower, 5.2kw hob, 3 ring finals and two lighting circuits and 2.8kw oven!
Can you get the current single phase supply upgraded or is it prohibitively expensive?

 

[Housebasher87]

i would ditch the two electric showers as @littlespark suggests and put either thermostatic showers off the electric boiler or maybe a good size pressurized cylinder (megaflow or likes) with immersion heaters in there if there is room for it.
The lighting circuits will be minimal draw with everything being LED these days and apart from the usual high load appliances the ring mains probably will rarely draw more than 16a most of the time (unless they have teenagers)
Maybe get a slightly lower kw hob like 5kw induction?!

Depending on the customer and their consumption you may just be ok with the above!

I did some work in a 3 bed log cabin a while back that was on a 50a type c mcb (already installed by others) that on paper should have really been on a bigger supply, speaking with the owner he said it had never tripped out in the 10 years they had been there.
Apart from the oil boiler was all electric with a 8.5kw shower, 5.2kw hob, 3 ring finals and two lighting circuits and 2.8kw oven!
Can you get the current single phase supply upgraded or is it prohibitively expensive?

I have told them to contact the DNO about getting the fuse size changed to 100a. Like you say depending on the customer and consumption may be ok. You don’t have 2x people showering at the same time, one on the pots and pans, someone running a hot tap and the heating all on at once. Also looking to ditch the 2x electric showers would help. I think they might just be pushed for space for tank. Thanks

 

[brianmoooore]

Max demand is calculated using diversity. Unfortunately, no diversity is allowed on water heating devices that can be on at the same time, so, as already said, it's the water heating that's the problem, especially electric showers.
A single electric boiler should be able to handle all of the water heating needs. It's output can be diverted from heating duties during the short periods that hot water is required for showers or other purposes without any noticeable effects.
Alternatively, electrical interlocks can be used to ensure that only one out of two showers and an electrical boiler is drawing power at any one time.