Nickthegreek

Maybe should be a new post - but it just blows my mind that 3-phase would be required for domestic use vs "30/100" single.  To me, it's what the grid can supply and, if they can adaquetly supply the 100a then why would anybody need 3-phase?

Nickthegreek, on 2012-02-03 14:18:43, said:

Nick you may want to repeat the check with all your aircons set to 18C to make sure they're running at the same time. If you turn them all off you can also check consumption of your IT kit to get an idea what the extra PCs will use.

Just post the figures here and I'll bash the numbers.

EDIT Whilst we're waiting:-

54000 BTU of A/C will draw about 23A, a further 9000 will add a further 5A = total of 28A on A/C

So if you can get your total of 46 PCs below 80W each you'll be OK, unlikely even if they're diskless

Check if you can upgrade to a 30/100 supply, it will be cheaper than having to go to 3-phase.

At first sight you're likely pushing things but why not check what you are actually using, it may well be a lot less than you think.

Go and buy or borrow a clamp type amp meter and stick it over your live incoming cable. If you can get a meter with peak hold so much the better so you can check for the actual maximum load.

Fire up everything you would normally use and check what you are actually using.

Whilst you're at it check one of the computers (you'll have to split out a cable so you just clamp the live), despite the fact they have 500W power supplies they will actually be using nothing like that.

A 9k A/C will use about 5A when running so add that plus 9x whatever the computer is using and you'll have your answer. If it goes anywhere near 45-50A you'll need a supply upgrade.

EDIT

Alternatively and cheaper (free) you can use your electricity meter. During a normal operating period observe your meter and count how many times the disc goes round in 5 minutes. Note the calibration factor of your meter (R/kWH) and then we can work out your average consumption.