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#26114 - 05/30/03 05:24 PM Single Wire Earth Return
jdevlin Offline
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Registered: 08/07/02
Posts: 402
Loc: welland ontario canada
I have been reading about SWER and how is used developing countries and Australia outback and is a poor system.
Well I was checking out the transformer on the pole in my back yard and it sure looks like it is hooked up SWER. The poles have 4 wires. 3 off them are the lines to the houses and the 4th is the high voltage. The transformer has 5 wires. The 2 that look like the primary have the high volt on one terminal and a wire coming down the pole to a ground rod the other. The other 3 go to the homes with the center one also connected to the ground. I live in the middle of a city in Ontario. This sure sounds like SWER. Is it?
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#26115 - 05/30/03 06:44 PM Re: Single Wire Earth Return
resqcapt19 Offline
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Registered: 11/10/00
Posts: 2148
Loc: IL
The primary and secondary share the same grounded conductor. It is not a SWER.
Don
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#26116 - 05/30/03 07:22 PM Re: Single Wire Earth Return
ElectricAL Offline
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Registered: 10/10/01
Posts: 597
Loc: Minneapolis, MN USA
Have you found this thread ?
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#26117 - 05/31/03 05:11 AM Re: Single Wire Earth Return
Trumpy Offline


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Registered: 07/05/02
Posts: 8211
Loc: SI,New Zealand
jdevlin,
You're unlikely to have SWER in the middle of Ontario.
SWER systems are really only used where it is un-economic to run more than two wires, and I'm talking way out in the sticks!.
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#26118 - 06/01/03 07:12 AM Re: Single Wire Earth Return
jdevlin Offline
Member
Registered: 08/07/02
Posts: 402
Loc: welland ontario canada
I read that thread. That is what got me thinking about this.
The primary has only one wire referenced to the ground rod. How is that different SWER just because the secondary is tied to the ground rod also.
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#26119 - 06/01/03 08:50 AM Re: Single Wire Earth Return
resqcapt19 Offline
Member
Registered: 11/10/00
Posts: 2148
Loc: IL
One grounded conductor carries both the primary and secondary current. The earth is not being used as a grounded conductor.
Don
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#26120 - 06/02/03 06:34 PM Re: Single Wire Earth Return
jdevlin Offline
Member
Registered: 08/07/02
Posts: 402
Loc: welland ontario canada
Ok I understand that. I was thinking from the primary side. I only have one wire coming in. Doesn't that mean the earth is used as the return to the power plant. That is what I thought SWER was.
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#26121 - 06/02/03 07:24 PM Re: Single Wire Earth Return
resqcapt19 Offline
Member
Registered: 11/10/00
Posts: 2148
Loc: IL
The common grounded conductor is connected to a conductor that returns to the power plant. The earth is not being used as a return.
Don
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#26122 - 06/02/03 08:44 PM Re: Single Wire Earth Return
ElectricAL Offline
Member
Registered: 10/10/01
Posts: 597
Loc: Minneapolis, MN USA
jdevlin

Take a close look at the neutral conductor in the seperate secondary wires that run from pole to pole. When the hot secondary conductors are broken so as not to connect two transformers together, the neutral will be kept continuous.

At each transformer, the secondary neutral will be bonded to the ground wire running down the pole to the butt plate (or ground ball or ground rod) as well as to the transformer can itself. The low side of the primary will be bonded to the inside of the can.

If there's cable TV and/or telephone on these poles, the support messengers for them will also be bonded to the same ground wire.

In my mind, I see the PoCo primary neutral interconnections as being similar to the way the NEC has us hook equipment grounds together out on branch circuits. . .if they are present at a location, they are all connected together. Kinda forms a web.
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#26123 - 06/03/03 03:52 AM Re: Single Wire Earth Return
Redsy Offline
Member
Registered: 03/28/01
Posts: 2056
Loc: Bucks County PA
Don,
Would these be autotransformers?
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