Holiday Home supply

[Von Vardo]

Wondering whether anyone can help me out with a diversity calculation.

A customer is building 2 log cabin holiday homes which contain the following circuits:

1 - Electric Boiler 10kW - 50A
2 - Electric Oven & Hob - 40A
3 - Ring final - 32A
4 - Ring final - 32A
5 - Immersion - 16A
6 - Lights - 6A
7 - Lights - 6A

When I try to work out the necessary supply size I get around 150A. Any pointers greatly appreciated.
Thanks

 

[telectrix]

i would imagine a 100A spply would be adequate. but i'd look into the feasability of LPG for the heating.

 

[davethsparky]

Can you just clarify whether that list of circuits is shared between both homes or if each home has that set of circuits?

 

[Von Vardo]

Each cabin has the same set of circuits. Unfortunately they don't want to put oil heating in so stuck with the electric boiler.

 

[bigspark17]

Get the DNO to put a100A supply in each unless you have adaquate power supply on current installation.?

 

[davethsparky]

Ok, a couple of things strike me about it then:

Why does it need a separate immersion when there is an electric boiler in there? surely that will be able to heat the hot water too? If the immersion is just a backup option as it would be if fitted to a normal domestic boiler system then ignore it for your calc as it will only have to be turned on if the boiler fails.

How big are these cabins? do they really need two ring mains?

 

[Von Vardo]

Yes, the immersions are there as backup for the boilers. The cabins each have 3 bedroooms and are quite large.

There are some farm buildings nearby with a 100A TPN supply - might it be possible to upgrade this supply to a larger one? I don't know what the next size up would be

 

[davethsparky]

Ignore the immersions then.

Get info from the makers of the boilers about diversity if any (probably not but worth an ask).

3 bedrooms, that'll be roughly naff-all load. what about the other rooms?

How did you arrive at the figure of 150A?

 

[Des 56]

I had a problem with a recent install where the available supply was not adequate for the intended load,this one had electric boiler,cooker, shower etc etc

I fitted a current sensing relay and contactor so that the electric heating would be off if the shower was in use
Perhaps you could overcome your concerns by doing similar with the cooker/heating circuits

 

[davethsparky]

Put the heating thermostat in the kitchen, heating won't come on while they're cooking then!

:21:

 

[Des 56]

Put the heating thermostat in the kitchen, heating won't come on while they're cooking then!

:21:

Now that is the kind of thinking that wins awards

My over engineered remedy trumped with the simplicity of the almost perfect solution


I take my hat off to you sir :flowers:

 

[davethsparky]

Why thankyou!

Personally I never take my hat off, the hair hiding underneath often offends!

 

[Engineer54]

Wondering whether anyone can help me out with a diversity calculation.

A customer is building 2 log cabin holiday homes which contain the following circuits:

1 - Electric Boiler 10kW - 50A
2 - Electric Oven & Hob - 40A
3 - Ring final - 32A
4 - Ring final - 32A
5 - Immersion - 16A
6 - Lights - 6A
7 - Lights - 6A

When I try to work out the necessary supply size I get around 150A. Any pointers greatly appreciated.
Thanks

Looking at those circuits and applying commonsense and experience, a single 100A supply will be more than adequate to supply both these rental holiday homes!!

The cooker circuit is over rated for what is going to be supplied in a rental cabin. The boiler will be thermostatically controlled to a set temperature, which won't be it's maximum. The ring circuits aren't going to be carrying any significant loading for more than 2 or 3 minutes The immersion is a back-up facility, so can be disregarded. Which leaves the 2 lighting circuits, no big loads there!! lol!!