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Posted By: JKWHITTED I have voltage drop - 12/12/06 01:58 AM
Coming from the breaker I have 240 but it drops down to 167 when I try to start blower motor. This goes through a phase converter. What could be the problem. I tested from the breaker
Posted By: ShockMe77 Re: I have voltage drop - 12/12/06 04:36 AM
How far away is the motor from the supply source?

What type and size are the conductors?

Phase converter's.... never worked with them before.
Posted By: girl germs Re: I have voltage drop - 12/12/06 05:47 AM
Don't know about this in the "real world" but I remember reading that there needs to be a transformer to adjust the supply voltage before entering the converter, to ensure the correct three-phase voltage (208?)...

is the 167V at the breaker? Have you tested if the three-phase is balancing properly?

hmmm.... *confused*
Posted By: JKWHITTED Re: I have voltage drop - 12/12/06 07:14 AM
it is 50 feet away using #10 wire . it is a soil vapor extractor first time at this site. it is along the railroad and the power is coming from a drop from the railroad pole.
Posted By: earlydean Re: I have voltage drop - 12/12/06 12:58 PM
What is the blower load?

With the blower off what is the voltage after the phase converter?
Posted By: JKWHITTED Re: I have voltage drop - 12/12/06 01:19 PM
460
Posted By: Zapped Re: I have voltage drop - 12/12/06 01:25 PM
If the supply voltage drops at the breaker, I would guess first that the problem is with the supply, and that the extra load is bringing the problem to the surface. It's probably either the PoCos problem, or you have a bad connection on your side.

Try tightening all lugs on your mains coming into the panel, and everywhere else that you can get to. Make sure all the busses are in good condition and that your breakers are seated properly and the contacts are all in good condition.

If that does nothing, call in your PoCo to check their connections at the x-fer and behind the meter (if you can't get behind the meter yourself because they have it locked out). ALWAYS BE THERE WHEN THEY COME OUT so you can show them the problem UNDER LOAD, or they will not see the problem at all.

I see this problem a lot pretty often,and it's usually a loose connection or a bad main feeder.

Please let us know what you find, and good luck!
Posted By: JKWHITTED Re: I have voltage drop - 12/12/06 01:41 PM
IT IS ON THE RAILROAD .. WE ARE GOING TO BRING IN GENERATOR IF WE CAN'T FIND A PROBLEM. I AM JUST WONDERING IF I HAD A BAD STARTER WOULD THIS CAUSE THIS.. I AM NOT ELECTRICIAN BUT HAVE GENERAL KNOWLEDGE. WHAT ABOUT THE PHASE CONVERTER ITSELF ? THANKS FOR YOU HELP
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