Compressor wiring, Backwards?

Despite the time my son spent in an electrical program at school I am not convinced he learned all that much BUT, I still hit him up from time to time for help.

The compressor I got last year had no high pressure cut off so I plumbed in a Square D unit I got and he wired it up in between the motor (from an old Embrel unit welded onto a 20 gallon tank from a DOA Sears unit) and the plug end (110v). We plugged it in and it immediatly tripped the GCFI pigtail I had inline. I took it out of the line as he thought the switch or something might be sending just enough to trip the switch (I am electrically illiterate). We then went to plug it into the wall socket direct it sparked pretty good when contact was made on the big prong. So, can anyone tell me what was done wrong here? The Square D unit has a PN# of 9013FHG12X

I can try to get a better pic of the inside of the motor elctrical box. The motor and compressor worked great guns last year but with no high pressure cut out switch it just compressed till it bogged the motor down and tripped the breaker.

The black cord in the foreground comes from the motor




I hope this pic gives someone some info. I lost the small direction paper that came with it.

Alright I found this.
http://ecatalog.squared.com/pubs/Machine%20Control/Condition%20Sensors/Pressure%20Switches,%20Water%20and%20Air/9013F/9013-890.pdf

Its the instruction manual but it looks like all you have to do is put the wires going to the motor on the inner post and the wires going to the wall on the outer post. I guess the pattern would be from left to right...wall white, motor white, motor black, wall black. Check the diagram and good luck.

-David

I'm no electrician, but it sure looks in the first pic that the two left terminals are bridged on the back side, and the two right terminals as well. If that's the case (and the pic isn't misleading) then you've essentially got the black and white wires from the plug tied together - creating a dead short.

David's wiring suggestion makes sense from what I can see...

Carl you need to have both blacks on one side and both whites on one side. What you have should trip the circuit breaker, taking the power (black wire) directly to the neutral (white wire), which creates a dead short. Also make sure your motor is wired for 110, there should be a diagram on the nameplate, or inside the lid of the wiring box. It may also be called low voltage. If you can wait til next year I'll come wire it for you.

Chuck! Good to see you. I caught that too. Dead short when the relay pulls in.

OK, thanks. So, I will put both whites on one side and both blacks on the other? Any chance this will go in reverse and not compress?

since its an AC motor it will only turn the way its supposed to.

CHUCK!!!!!!!!!!!! :D Don't stay away so long!!!

"If you can wait til next year I'll come wire it for you"

Hey Chuck, that sounds pretty good! Not the wiring bit ( I should have it running well before) but the coming here bit! When are you coming to Maine and where are you going to be?

some single phase a/c motors can be wired to run both ways, but this is unusual. Check the nameplate data. And we are hoping to spend a bit of time in New England in conjunction with the NAMGBR convention in valley forge

Some DPO painted over the sticker/plate on the motor. We have never been able to find out anything on it other than it was an Embrel unit.

What the others said - it is wired to short-circuit in the picture.

However, I would keep the picture, preferably blown up to poster size. It may come in handy as a tool for reminding the lad he doesn't, actually, know everything! ;)

Let us know if switching the wires works.

By the way - good to see Chuck here!