What size transformer for new connection?

jakko86

Hi all I'm currently building a house and looking for a new connection and I'm unsure what size transformer I need to apply for, I have 2 ovens on seperate switches, a hob no electric showers all pier showers off a pump. Underfloor heating off a condenser boiler a garage for doing odd bits of carpentry, electric gates in the fruit, nothing else with major wattage that I can think of? Any help on this would be great?

foxy farmer

Most domestic installations would be supplied from a 15kva single phase transformer. Your max demand would be 63A(main fuse) × 230v=14.490 kw. 5kva trafos used for very small loads like remote pump houses etc. 33kva also common but mostly used for multiple consumers. Wouldn't be needed in your case. Don't even think about 3 phase unless you badly need it for equipment and it's practically outside your door. Any idea what connection fee is now? I paid around €1300 in 2003.

adrian92

Generally the electricity utility will decide the transformer size. In your application form for a new (or increased) electricity supply you will be asked to list all your installed load details. the utility will make the necessary allowances for diversity (ie non-coincidental load), and other factors, and arrive at the transformer size (level of supply) required.

It would be important you list all your planned load as accurately as you can estimate.

The transformer size will be decided by the utility.

jakko86

12kva is standard 1800 euro next up is 16kva for 2400 ish so I'm not sure which to go for I also have a well so I'll be powering a pump for that?

foxy farmer wrote: »

Most domestic installations would be supplied from a 15kva single phase transformer. Your max demand would be 63A(main fuse) × 230v=14.490 kw. 5kva trafos used for very small loads like remote pump houses etc. 33kva also common but mostly used for multiple consumers. Wouldn't be needed in your case. Don't even think about 3 phase unless you badly need it for equipment and it's practically outside your door. Any idea what connection fee is now? I paid around €1300 in 2003.

jakko86

The esb are asking me what I want there are some examples on the form but nothing that I can make sense of really.

adrian92 wrote: »

Generally the electricity utility will decide the transformer size. In your application form for a new (or increased) electricity supply you will be asked to list all your installed load details. the utility will make the necessary allowances for diversity (ie non-coincidental load), and other factors, and arrive at the transformer size (level of supply) required.

It would be important you list all your planned load as accurately as you can estimate.

The transformer size will be decided by the utility.

adrian92

Rather than try to fill in the ESB form section with load details - which certainly used to be, in my view, a bit unclear - I suggest you simply , on a sheet of paper separately fill out, as well as you can, your installed load as you did here - list each significant item and estimated load ; you could add a list of incidentals with no load details (eg. "general domestic items toaster, microwave, etc."-this would I think be enough for come up with the trafo size etc.

tomdempsey200

12kva should be ok
consult your electrical contractor

you've no elec. showers

a few cooking appliances... there's a load of diversity on that


if you want spare capacity you can get the 16kva

sometimes out the country you'll get a better quality supply if you specify 16kva..but you're entitled to it with 12kva anyhow

2011

jakko86 wrote: »

12kva is standard 1800 euro next up is 16kva for 2400 ish so I'm not sure which to go for I also have a well so I'll be powering a pump for that?

Everything that you have said so far points to a 12kVA supply. A 16kVA would be more appropriate if you had something like a heat pump.

The well water pumps generally are normally a small electrical load, the same applies to electric gates if you are concerned check the ratings.
My biggest concern would be the ovens and hob.

Normally the electrical contractor deals with the filling out of this form.

tomdempsey200

yes it looks like 12kva is sufficient

if you think you may want to add an instant shower welding etc I'd be looking at 16kva

usually out the country if the lines are bad i'd have asked the customers to apply for 16kva.. the utility company would then bring the MV close to house
and fit a trafo

jakko86

tomdempsey200 wrote: »

yes it looks like 12kva is sufficient

if you think you may want to add an instant shower welding etc I'd be looking at 16kva

usually out the country if the lines are bad i'd have asked the customers to apply for 16kva.. the utility company would then bring the MV close to house
and fit a trafo

Thanks for the replys. So if I was to do small bits of welding in the garage I'd need the 16kva? All appliances would have to be on at the same time to exceed the 12kva transformer?

2011

jakko86 wrote: »

Thanks for the replys. So if I was to do small bits of welding in the garage I'd need the 16kva?

If it is electric arc a16kVA would be better.

All appliances would have to be on at the same time to exceed the 12kva transformer?

Yes, Google diversity factor.