Compressor troubleshooting

[Jamesbbh]

Hey guys! First post here, I got a really good deal on this 10-15 yr old unit made by Magnum?> They went out of business from what I understand.

220v twin cyl. 6.5 hp

This is the plug I'm using for it that was previously installed in the shop- It looks like a 3 wire going to a 2 pole breaker. What's odd is the wire looks like 4 or 6 gauge inside the box? Is that normal? There is also a cut-off switch on the other side of the shop that doesnt appear to work (or is connected to another outlet) I'll figure that part out later.

So I went and got some stuff to make a power cord out of 10/3

White/Black hot and green to pin

Wired it into the box to terminals marked "line-line" and "motor-motor" and grounded the motor and cord seperately inside the pressure switch.

Now problems:
- the motor wants to start but just flips the reset switch by the capacitors after about 1 second
- Motor started once and ran fine for about 5 minutes before I shut it off and now it's still flipping the switch.
- Motor was a little warm to the touch even before it started and ran for 5 minutes.

Is it the "run" cap that is causing these problems? Could it have something to do with the breaker itself? It's labeled for a 2 pole breaker inside the cover for the pressure switch.

Any and all help greatly appreciated!

Oh and a pic of my dog just for S&G's

 

[Jamesbbh]

Here's a really ugly wiring diagram I just drew up.

 

[pattenp]

Have you removed the drive belt to see if the motor runs fine with no load and also that the compressor pump turns by hand without a ton of effort? You can sometimes tell if a capacitor is bad by looking at the top where the wires connect. The top should be flat. If the top is domed or curved up then most likely the capacitor is bad.

 

[Zrexxer]

Hey guys! First post here, I got a really good deal on this 10-15 yr old unit made by Magnum?> They went out of business from what I understand.]

I believe the "Magnum" branded compressors were the one sold by the Homier traveling tool gypsies. Buddy of mine has one on smaller tank that's just about identical to that.

 

[Jamesbbh]

Have you removed the drive belt to see if the motor runs fine with no load and also that the compressor pump turns by hand without a ton of effort? You can sometimes tell if a capacitor is bad by looking at the top where the wires connect. The top should be flat. If the top is domed or curved up then most likely the capacitor is bad.

I'll have to do that when I get home- I can say it isn't very hard to turn the whole assembly by hand. For $100 investment I don't think it's too bad so far haha

 

[larry_g]

Also double check that the motor is wired for 240v. If it is a 120/240 motor it could be wired for 120.

lg
no neat sig line

 

[71flh]

I'm new here, so I have no credibility, but I'll bet that pressure switch isn't rated anywhere near the current that motor pulls. You may want to look at the motor and switch current ratings.

Its not the source of the motor not running problem unless the contacts are fried, but it should be a concern down the road.

 

[Jamesbbh]

Well it's not the actual pressure switch that is flipping off- it's the overload/reset switch that is wired in the box with the start and run capacitors. The guy said he saw it running when he unwired it form another guys shop- and for only $100, I don't know why he would even lie about it haha.

 

[darkk]

The box with the capacitors in it...does it have some little fiber/hard plastic blocks with a screw head looking thing in it? In other words does this motor start with a heater==>a time fuse system that allows a large power surge to start the motor without blowing a fuse. If one is burned out the motor with start and run no load but will trip the breaker if it has a load on it because one side is not live.

 

[Jamesbbh]

The box with the capacitors in it...does it have some little fiber/hard plastic blocks with a screw head looking thing in it? In other words does this motor start with a heater==>a time fuse system that allows a large power surge to start the motor without blowing a fuse. If one is burned out the motor with start and run no load but will trip the breaker if it has a load on it because one side is not live.

It has a little distribution block that looks like it's made out of porcelain or something along those lines that hooks directly into the top of the motor. Is that what you mean? It hasn't flipped the breaker yet, just the "reset" switch. I know all of the in's/out's of vehicle wiring but home wiring is fairly new to me so I've been taking every precaution I can so far haha.

Thanks for the help so far guys!

 

[Jamesbbh]

Well it's been a while and I forgot about this thread but I got it running! It was the start cap- I just took the motor off and hauled it down to a mom & pop electrical motor repair place to get everything checked out. $20 later it's running woooooo

Also started building this little air cooler/dryer that will be mounted directly in front of the shop AC window unit.