electricians, help me please

[shermanator 4]

I just replaced a rotron motor (3 phase 230v 1.75hp)and after 8 hours of operating, the system it is running on shut down.

I was troubleshooting, and found that each individual leg was showing 234V *on the entire circuit, not just that motor* Checked my wiring, and it was wired correctly. played with some fuses in the panel, could not find anything out of the ordinary, other than a couple loose wire connections that I fixed. when I checked the motor wiring, I found that the brand new motor burned up on the inside, and is now no good.

what could cause the motor to burn up. and why would I get 230 on a single leg, instead of 120? Oh, also, one leg, was showing no voltage, but when I disconnected the motor completely, all legs showed 120v single, and 230 with any two.

sorry my description is very confusing. maybe someone can help.

CLICK HERE! new blog posted 9/21/08
CSA #720

[piratemike 0]

So I'm a little confused by your "234V *on the entire circuit, not just that motor*" statement.

You should have 4 wires going into that motor, L1, L2, L3, and neutral.

First off, make sure you have a true-RMS voltmeter, or your measurements can be off quite a bit.

L1 to neutral should read 108-118
L2 to neutral should read 108-118
L3 to neutral should read 205-210
you should read 240 V between any two phases

L3 is called the high line, it should be a orange or red wire.

If you misswired the high line to one of the other poles, you can blow out the motor, or, often you will blow out one of the fusible links going to the motor.

If you get a single fuse burn out somewhere in the system, you can burn up a motor winding. (this problem is the a reason that you will often see a separate fuse box right at the motor)
Check for fuses on your device, go to the circuit breaker, check the voltages on all three legs coming out of the breaker(check the voltages going into the breaker panel if you want). You need to be getting voltage the whole way from the incoming line to the motor.

Sorry to hear about this, those motors can get pricey.