DIY wiring a 3 phase compressor?
- Thread starter GlennRobinson
- Start date
wyliesdiesels
Well-known member
Ok so its a DP- definite purpose, contactor, which most likely means the coil cant be changed.
The coil is 120v based on the control transformer label.
looks like the primary side of the CT is connected to 230v, so you're good there.
what is the rating on the fuses? they may need to be changed.
The contactor is rated for 7.5HP 230v 1Ø, so you're good there.
Can't tell what size wire comes off the overload block but it needs to be 50a rated wire, #8 THWN
The coil is 120v based on the control transformer label.
looks like the primary side of the CT is connected to 230v, so you're good there.
what is the rating on the fuses? they may need to be changed.
The contactor is rated for 7.5HP 230v 1Ø, so you're good there.
Can't tell what size wire comes off the overload block but it needs to be 50a rated wire, #8 THWN
Last edited:
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GlennRobinson
Member
OP
GlennRobinson
Member
wyliesdiesels
Well-known member
the heaters you have are E7- 21.9-24.4a. too small for a 7.5HP 1Ø motor, which would have an FLA of around 35a.
Doesnt look like that heater series goes above 33a.
Doesnt look like that heater series goes above 33a.
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GlennRobinson
Member
Thought I had an idea of how much I didn't know. Guess I was wrong.
So does this mean I am back to looking a phase converter or VFD?
Glenn
So does this mean I am back to looking a phase converter or VFD?
Glenn
TractorJeff
Well-known member
Why does the photo with the MAIN breaker have 4 Breakers tied to one handle?
Because it's a factory assembly, it is actually a 2 pole breaker, ITE was the first company to build them that way in the mid 1970's, Cutler-Hammer, GE, & I think SQ D copied the idea.
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GlennRobinson
Member
Update - While cleaning up the compressor, I went to empty any condensation in the tank and was quite surprised at the volume. I drained 30-40 GALLONS of rusty water. Based on this finding, I am returning the compressor to the seller. He has agreed to a full refund.
A big thanks to everyone for the education. I will be limiting my shopping to single phase compressors.
Glenn
A big thanks to everyone for the education. I will be limiting my shopping to single phase compressors.
Glenn
wyliesdiesels
Well-known member
its a 200a breaker. Each pole has 2 100a breakers, sandwiched together.
wyliesdiesels
Well-known member
Wow, that's a lot of water. Good call on returning it. Good luck on the compressor search!