8 hots, no neutral, 1 ground?!?
8 hots, no neutral, 1 ground?!?
(OP)
I just checked out a friend's new place, an old cigar factory (now residential). He wants power outlets on his walls, so I opened up the j-box that used to be feeding some roof-mounted air conditioning units. What I found were 7 120v lines, one line at 208v to ground, and one ground. All were 12 ga. multi-strand. There are a few things I don't get: a) how can one line be 208 w/respect to ground, rather than w/respect to another as in 3 phase wye. B) why no neutral, and what can I do about it to get the guy some power in his place? The subpanel had 4 wires coming in: 3 2 ga. wires at 120, 120, and 208, and one flimsy ground wire (10 ga). No neutral bus, no ground bus. Plus, the 208 feed was at 240v w/respect to the other two 120 feeds. Anybody have any insight? Thanks!






RE: 8 hots, no neutral, 1 ground?!?
You have two options to use this and meet NEC requirements.
1) Bring properly sized ground and neutral conductors to the subpanel.
2) Remove the subpanel and use that circuit to feed a 240V delta - 208Y/120V transformer. The transformer can then feed a new panel with a main breaker, or you could use an enclosed breaker as the main and potentially reuse the subpanel on the 208V system.
RE: 8 hots, no neutral, 1 ground?!?
The "B" phase is about 208 VAC to the neutral point. The ground wire in the box feeding the rooftop units would be connected to neutral back at the service, so it works to test the voltage of the 3 hot legs, but not to run loads. Maybe you can reposition the "B" phase hot to the subpanel and J box and label it to get the neutral you need.
Just stay off that 208 with your plugs!
RE: 8 hots, no neutral, 1 ground?!?
RE: 8 hots, no neutral, 1 ground?!?
Should a delta system installed in residential environment be a concern from the safety point of view?
RE: 8 hots, no neutral, 1 ground?!?
Phase B is commonly called the wild leg.
I thought the voltage was higher than 208 (wild leg to center tap / neutral / ground)
RE: 8 hots, no neutral, 1 ground?!?
RE: 8 hots, no neutral, 1 ground?!?
RE: 8 hots, no neutral, 1 ground?!?
I would not want to have this setting in a dweling unit. (I don't like this setting even in a commercial or industrial facility)If possible, cap the high-leg at the source (Main disconnect at the electrical service) and keep the other 2 phases and provide an approved neutral and ground conductor as per David advice. With this new set of conductors, feed a 120/240V, single phase, 3 wire panelboard or load center and rewire the branch circuits that need to remain operational.
RE: 8 hots, no neutral, 1 ground?!?
Invest in good smoke detectors. :)