Ground/Neutral Woes

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Old 08-11-18, 01:06 PM
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Ground/Neutral Woes

First timer here with a serious dilemma. We are planning a new home in the country, the property has single phase service to home, 3 phase to shop with no nuetral. The old house was not habitable so weíve been running 30 amp power to Rv from shop, and additional ext from house. Partly because weird flucautions from shop. House gets demolished, and power company says because of no nuetral to 3 phase, nothing should be running but pump for well. My demo guy has electrician run a wire from pole to sub panel for nuetral. But power is still not right, canít run AC, fans surge, but enough power to run smaller appliances. Thoughts? Oh and itís hot, so we need a fix quick.
 
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Old 08-11-18, 03:35 PM
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Buy an electric generator? Gas, or solar....
 
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Old 08-11-18, 06:19 PM
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Welcome to the forums.

It's not a ground woe...... it's a non existent neutral woe.

Pretty strange to see mixed services in a residential area. For you to have three phase service there should be three transformers. It sounds like you have a delta service in the garage which is three phase and no neutral. You cannot just "add" a neutral on.

You will either need to change the service in the garage to a Wye type service where you have three phases and a neutral or have them set a temporary service pole up during construction.

You could add a three phase transformer in the garage that gave you a neutral.
 
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Old 08-12-18, 12:13 PM
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Cost

PJmax, the question is cost at this point. Since we will be changing everything in the end. The temp service is 1000 Permit, plus cost to wire new panel. So Iíll check into transformer you mentioned, any idea on that? Thanks for the straight answer, multiple guys have all these ideas but nobody has said, yes it will work or no it wonít.
 
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Old 08-12-18, 12:29 PM
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You may have a high leg/red leg service there where one of the 3 phases is higher in voltage to ground than the others.

Do you have an electrician you are working with ?
He should be able to get you a transformer to convert from delta to wye.
A new transformer could be in the $500-750 range. Many electricians have old ones lying around or know where to get used ones.
 
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Old 08-12-18, 05:51 PM
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have them set a temporary service pole up during construction.

A temporary service pole for construction would be my first choice. A transformer would be my last choice.


3 phase to shop with no nuetral.

What was the 3-phase being used for when you bought the property? Didn't they have any lights in the shop or did you also have single phase from the house feeding the shop?
 
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Old 08-13-18, 08:34 AM
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Cost/Conversion

I have a few electricians giving me opinions. One said the transformer, the other says do the temp service, itís cleaner and safer. The 3 phase mustíve been for years ago, it was only feeding a panel where it serviced the well and a few outlets. From what I understand now, the house was acting as a nuetral/ground since that panel was grounded to the house water supply. House is gone, so theres no consistent loop. I already fried a tv the first day, and they say Iím taking chances doing more damage with the voltage spiking. I think Iíll bite the bullet and pay utility for the temp service. Itís just a bummer to not be able to use all that power that is here.
 
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Old 08-13-18, 12:03 PM
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the house was acting as a neutral/ground since that panel was grounded to the house water supply
That is not correct and is very dangerous.
That is a very strange setup and should be thoroughly checked out by an electrician.
 
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Old 08-13-18, 08:01 PM
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I already fried a tv the first day, and they say Iím taking chances doing more damage with the voltage spiking.

If all you have is 3-wire 3-phase why would you think you could use a TV? What are you using for lights? I don't see voltage spikes as much of a problem, but not having a 120 volt and grounded neutral conductor would be a huge problem.
 
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Old 08-14-18, 07:22 PM
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Casualjoe, to be clear, from the 3 phase breaker box on the pole, 2 red leads go into a subpanel in the shop. That panel is grounded out to a few grounding rods and the water pipe going to the house. And one electrician went up the pole and thought he was connecting to a nuetral wire, since the 3 phase didn't have one, but that didn't do anything. All I know, is it all worked before the house went down!
 
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Old 08-15-18, 01:43 PM
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It really sounds like the shop service was only designed to run the pump. Your electrician and/or the power company might be able to rewire the transformer bank into a wye configuration which would be usable for any type of residential or commercial loads. That might also require some rewiring or replacement of the pump.

For now, I think the quickest and safest option is to have a temporary construction service installed.
 
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Old 08-15-18, 05:55 PM
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What is the phase to phase voltage of your service? It should be the same for each pairing of hot lines.

You can get an ordinary stand alone transformer of a about 2500 to 4000 watts whose primary is for the phase to phase voltage of your service and whose secondary then yields 120 volts. Use that temporarily to power a small amount of 120 volt equipment. More than that many watts and you should have two or three of those transformers to balance the load on the existing 3 phase delta service.

The transformers are wired into the 3 phase service panel. Their secondaries are either fused at 20 amps (@ 120 volts) or (for 4000 or so watt transformers) run into subpanels to provide 15 or 20 amp 120 volt branch circuits.

Ultimately you need 120/240 volt or 120/208 volt service, the latter is often supplied when a group of buildings needs 3 phase and there are some homes in that group. Then you won't need the transformer any more.
 
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