delta system
delta system
(OP)
we have a 240v delta system 3 wire how do you get a neutral
we have it to ground been fine for years a least 18. now we have unbalaced power to ground it is 147 195 94 volts changed the grounds didnt help penelec don't even no way
we have it to ground been fine for years a least 18. now we have unbalaced power to ground it is 147 195 94 volts changed the grounds didnt help penelec don't even no way






RE: delta system
It doesn't seem to be a problem to me. No severe unbalance - you have to expect anything between almost zero and full line/line voltage in such a system.
Is your question how to ground it? If that is the case then you obviously cannot ground the transformer center point to get a 240/138 V system. But - if your country's code permits - you can ground one of the phases and get a grounded delta with 0, 240, 240 V from line to ground. It is being done in the US and it really doesn't change much. Only that a ground fault in one of the hot phases will trip the corresponding fuse, which could be good.
I think that more and clearer information is needed before anyone can give advice here.
RE: delta system
Another option if you need a small amount of 120/240 volt single-phase power may be to have the utility convert the service to a 240 volt "high leg" system where a center tap of one of the three transformers (or transformer windings) is grounded. This effectively adds a 120/240 single phase connection using two of the three 240V phases and the added 'neutral'.
Theoretically you can ground one phase of the existing 3-wire system, converting it to what is called a 'corner grounded' system, but that doesn't give you any other voltages to use.
RE: delta system
Send me email mc5w at earthlink dot net if you want details as to how to protect a balance coil or zig-zag set against overloads and internal faults. Ordinary circuit breakers or fuses will not work.
Mike Cole
RE: delta system
I hope this helps
Bill
RE: delta system