Electric lines

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TreeHouser
Joined
Feb 26, 2012
Messages
999
Location
Eastern PA
Today I was working near some electric lines doing clearance. It was triple phase to the pole where it dropped to what looked like a normal house drop line and then back to triple phase. Had not seen it like that before. My bucket is insulated so I wasn’t worried but then again I don’t know much about electric and I hear different things about what an insulated bucket can do. Who here has got some knowledge on the subject?
 
Was there a transformer on the pole? Telltale clue to presence of high voltage. Also bare conductors. 220V is generally insulated wire, generally 2 phases dropped to a house. Same risk as the cord on your kitchen stove. High voltage (thousands) - bad risk.
 
Pay attention to the wire diameter and the number of insulators on the pole. The fatter the wire, the more juice. The more insulators, the more juice. Typical neighborhood distribution lines are 7200v. Anything after the transformer is 240 standard house drop with insulated wires, no big deal just don't grab them with a bare hand.
 
3 phase doesn't mean much as far as increased danger other than no neutral line and technically more power carrying capacity. Large diameter wires do carry more juice, but depending on where you see them, it can be a sign that the voltage is low. Small wires can carry limited amps, so they tend to carry very high voltage to be able to still carry lots of power. Voltage is what jumps gaps and travels long distances even though it's the amps that kill. The amps can't get to you if the voltage isn't high enough to cross poor conductors like air or moist surfaces.
 
Another sign of high voltage is wires hanging on insulators. A house pole drop generally has a plain strain relief mount at 220v.
 
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I guess what confused me was that the electric company used part of the old lines. So the primary’s came in from the road to a transformer where it dropped to an ordinary house line. Then connected to the old triple phase with ceramic at both ends, then back to a house line again.
 
I guess what confused me was that the electric company used part of the old lines. So the primary’s came in from the road to a transformer where it dropped to an ordinary house line. Then connected to the old triple phase with ceramic at both ends, then back to a house line again.
I am an electrician. I have working but shallow knowledge of how utility companies run their lines in poles. The way you describe it I don’t think it’s three phase. Sounds like, as you say, they, are re-using some outdated wiring that has an insulated neutral conductor supported on ceramic insulators instead of the more common bare messenger wire/neutral with two insulated conductors wrapped around the messenger. The common modern method is called triplex cable. I attached a picture of triplex and a couple pictures of old fashioned service drops using individual conductors instead.
 

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