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My existing overhead wire is triplex 1/0, 2 insulated and one bare. The power company is out of the picture because they do not provide service to a customer supplied pole.

My existing wire is at a 20 ' pole , 5 feet from the weatherhead at the shop. The mast is 10' , 2 inch galv. pipe with a lbr going into the shop behind the load center.

Questions are: Can I just splice in an 18' section of 1/0 triplex and be done with it?

Should I splice in a 4/0 triplex using a mechanical reducer splice? 4/0 is because of the weatherhead and mast. Not sure if required because it is not a residence.

Should I even use a triplex wire with a bare neutral in a metal conduit?

Items on the service are :

  • deep well pump 20a
  • Welder 50a
  • Compressor 30a
  • Lift 30a
  • Lights 15a
  • Outlet 20a
  • Outlet 20a

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  • Could you also include a picture of the shop breaker box showing the breakers and also the grounding system... either via ground rods or UFER – Kris Feb 19 at 17:38
  • No breakers are installed yet. I have a 7/16 copper rod 3 feet behind the pole with 4ga copper running to the load center. – Timothy Ryan Feb 19 at 17:45
  • The load center should have a main disconnect – Kris Feb 19 at 17:59
  • It has one 400 ft away by the meter pole. Should I have another or is the 200 amp main at the load center good enough? – Timothy Ryan Feb 19 at 19:22
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    This was A pole barn for the last 40 years with lots of machinery and welders running. I just had to tear it down because of termites. Now I have a new metal building trying to install new electric. – Timothy Ryan Feb 19 at 20:52
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We simply need more information: How far to the shop? Is the meter base at the shop? A picture/diagram of property would be helpful; include distances.

If the panel shown here is equipped with a main breaker, there is no need for an additional disconnect. I see no need for the pole as all. Just strike to the mast.

If it is indeed 400-feet to the meter base you are going to have a fairly serious voltage drop problem. The voltage is based upon the amount of actual current used at any one time.

If the pole is required for ground clearance than don't splice at the pole just strike to the pole and continue to the weather head.

Technically you need a quad-plex or 4-wires as the feeder. After the service the neutral is separated from the ground. I would recommend an underground feeder. I would put it down 4-5 feet for protection.

If you could give me the estimated max current draw at any one time we could recommend a wire size. That means that when you strike an arc with the welder what is the actual current draw of the welder on the circuit. And when the pump actually runs and is pumping full bore, what is the current draw on the pump motor. And when the compressor is running nearing the shut-off point what is that motor drawing. And what is the actual amp draw on the lights? Then throw in 10 or 12 amps for power and bench tools per number of men that will be using the building at any one time. With this we can give you wire size.

Do you ever plan to heat the building?

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    Thank you Paul! The meter is 400 feet away with a disconnect. The shop will only be used when needed snd not on a daily basis. The welded is the largest draw max 50 amp snd I hardly think I will need to set it that high. The air compressor is the next largest user at 30 amp max. It may kick on when welding is going on and I never noticed any change in sound while welding. I have thought of a heater but not at this time. I do understand that could be an issue later down the road when I'm gone. I'd hate to stick the problem with my sons. I need the clearance so that is why I put in the pole. – Timothy Ryan Feb 20 at 0:01
  • Paul, the welder can peak at 50a. The compressor is rated at 25a. When I replaced the pump 5 years ago each leg showed 8 amps at turn on and tapered off to 6.5a. Lighting is all led, 16 at 47 watt each. I exterior light at 150 watts. I do not have the lift yet but it calls for a 30 amp circuit. I wish I could go underground. The plumbing for the deep well is in the way and was the reason the first underground cable was cut. 3 others tap into my pump house for water, right where the cable was buried. – Timothy Ryan Feb 20 at 1:00
  • Thanks to all for the help. I am having an electrician come out to evaluate my situation. I will come back and tell you what the resolution was. I am thinking a new quad-plex as was mention here. – Timothy Ryan Feb 20 at 14:43
  • Good Plan. Good Luck. – Paul Logan Feb 21 at 4:00
  • I am not much interest to an electrician I guess. Can't get anyone out to the house. Still not done yet. – Timothy Ryan Mar 11 at 20:51
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It appears that since you are not replacing the overhead line, (and since doing so would be onerous), this setup is grandfathered. As such, you will need to bond neutral and ground in your barn panel.

If you're feeding straight off the meter, then it's a bit of a weird setup, with the potential for problems. If you're feeding off a breaker in your main panel, just know that the grandfathering introduces some safety hazards, and you would never do it on a new installation.

Now, you will have some pretty brutal voltage drop. If that becomes a problem and you want to do all of the following: reduce your voltage drop by 75%, b) double your current capacity (at this doubled capacity voltage drop will be half what it is now), and c) make this setup a whole lot safer... then let us know and we can advise a very good way to do that. It will not require replacing the overhead line, just installing some equipment at both ends.

  • I may want to make my setup safer. Before I buy 20 feet of 4/0-4/0-4/0 SEU cable what else do I need? I do have my 4/0 to 1/0 reducer crimps. – Timothy Ryan Mar 14 at 13:26

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