# Give me your opinion/advice on this job...thanks.



## Electrical Ace (Aug 27, 2009)

I'm a Canadian electrician and currently travelling around the middle east adventuring and working. I came upon this job which sounds pretty interesting and I will probably take it on. Give me your advice or opinion on how you would tackle it.

20 solar water heaters are being installed, each will have a 2000 watt electrical heater. I have to take power off a local pole which is 3 phase plus neutral (voltage is never constant, varies from 200-220v, so I'm assuming worst case calculations at 200v). I was thinking of taking only two hots and the neutral to a main 2 pole 250amp breaker. Then I would take each hot leg to a 125amp contactor which would be enabled by a computer that monitors the water temperature and turns on the heaters when required. I was then going to take two runs (one from each contactor) up to the roof and each run would pick up 10 solar water heaters.

Talking to some local guys here, everyone seems to have their own opinion. Some say bring only a two wire off the pole, others say bring a 4 wire off the pole. Some say use 20 relays to control each heaters.
I'm looking for the safest and most economical way on doing this job.
What do you think?


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## vizzolts (Sep 10, 2009)

#1. You don't need 250A, and you'd be better off running 3 phase. 
200V X 150A X 1.73 = 51.9KW



#2. You'd be better off running each branch circuit through its own 20A contactor.


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## josh5879 (Sep 21, 2009)

Just curious what country are you in?


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## Toronto Sparky (Apr 12, 2009)

Three phase... always (if it's there).
Why would you take a neutral?


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