220Y/127v 3 phase 4 wire

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pelican

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I have recently learned that Rio Power Co sets subject aerial transformers to serve just about houses, strip malls, etc. I believe the subject voltage is comparable to NEC 208Y/120V.

Appreciate your help on this 2 part design:
First I have a group of buildings with a total load of 35kva and maybe up to 50kva all single phase. Rio will set the pole and install 3 phase TX and run their secondary to a meter below the TX. I will come out of their meter and take 4 secondary wires about 100 feet to a main building. I think I should install a 3 phase 200 amp panel, even though I do not need 3 phase. Then I suppose I use all of those 3 phases for single phase load balancing service throughout the main building, and to feed other building's panels that are downstream. This way I will have single phase at 220v AB, BC, and AC. And also 127v A, B and C phases to neutral, with the neutral grounded. Is this approach ok?
What type of panel do I use for this?

Part 2: I must serve 5 homes UG each will have a 100 amp panel. Rio does not use padmounts so they will set another 3 phase TX pole and come down the pole to their meter. Then I go from the meter onto a rack mounted trough, then split-bolt the 4 wires in the trough(abn, bcn, acn, abn and bcn)and go out of the bottom of the trough to 5-100 amp fused disconnect switches. Then out of the bottom of the switches UG to each of the homes 100 amp panels. Is this approach ok? Thank you.

[ July 29, 2004, 09:16 PM: Message edited by: pelican ]
 
Re: 220Y/127v 3 phase 4 wire

Personally I think 220/127 is a bit high and would use the (2)+2-1/2% primary taps that should be available on the transformer to compensate for the high secondary voltage. By using the +5% tap you can reduce the secondary voltage to about 208y/120.
 
Re: 220Y/127v 3 phase 4 wire

Unfortunately this is the voltage info I am getting from Brazil. As you know, it's the power companies transformer so I doubt would have any stroke in changing their taps. Thanks.
 
Re: 220Y/127v 3 phase 4 wire

Here in the states we have to meter each dwelling as it would be hard to tell how much each one uses.
But I don't know for down there. but if you can have a meter for each house it would make common since to alternate each house per phase so you keep the phases balanced. But I'm not quit sure which way your talking about. If you have to use one meter for five houses then use a three phase service panel R-3 rated if you can get a meter for each dwelling then just go with a single phase service panel and alternate each service.

[ July 30, 2004, 08:25 PM: Message edited by: hurk27 ]
 
Re: 220Y/127v 3 phase 4 wire

I plan to propose to the Rio Power Co. the 2 meter approach because it will be a lot easier on the billing-paperwork. This design is for a Children's Village that will house Rio street kids, 12 kids with parents to a house. The metering is a factor, but I believe Rio will be able to take care of that.

What I would appreciate is whether my approach to serving these 5 homes and the Villiage's support facilities is correct per NEC. I welcome the comments. Thanks.
 
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