240 volt 3 phase delta

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gsurace said:
One question about this system, I checked the voltage, phase to ground, on the leg which passed straight though and got 516V. Does this sound right? I did measure 230V phase-phase. I did not, for some reason, check the other two phases to ground.
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In an ungrounded system is is possible for you to measure all sorts of weird voltages L-G. It all depends on the amount of coupling capacitance in the system and the impedance of your meter.

If you have a 240V nominal system you only need to use equipment that has been rated for use on a 240V ungrounded delta system.
 
Sure. Not sure which part to elaborate on but I'll try to clarify.

I've an existing 3 phase 3 wire 230V Delta service coming into the single phase meter base. I need to replace the main panel and when I pulled the meter and checked the voltage at the main panel, it only shut off 2 phases. To verify, I checked each phase on the load side of the meter to ground. Found 0V on 2 of them and 516V on the 3rd which obviously was the phase which passed right through the meter base on the center neutral bar.

After finding how high the voltage was on that center leg, I checked the line side of the meter, phase-phase and found all were 230V. That's where I stopped because I had a conductor with very high voltage on it and no way to shut it off.
 
Confused

Confused

gsurace said:
Found 0V on 2 of them and 516V on the 3rd which obviously was the phase which passed right through the meter base on the center neutral bar.
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Now I am confused. If the unmetered phase conductor connected to the center (normally neutral) position, it would be bolted to the meter fitting and grounded. If it is an ungrounded service, that connection would ground that phase and you would no longer have an ungrounded system. You also would have 0 volts to ground from that point or that phase but you would measure 240 volts to ground from the other two phases.

What is wrong with my thinking? :confused:
 
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