air compressor blew capacitor - need replacement

[wuntunearlybko]

so i bought an IR SS5 single stage 5 years ago and has served me quite well. i was fabbing up a new fire pit this weekend and while using my plasma cutter my breaker tripped. i went upstairs to check and found a clear liquid oozing from under one of the humps on the elec motor. i pulled the capacitor cover and found what looked like an exploded capacitor the top was completely dangling and foil/paper packing poofing out.

Sooooooo, it looks like i need to replace the capacitor. my questions are
1) any idea why this happened? poor quality or just inevitable?
2) is this capacitor the run or start? it is the capacitor closest to the pump
3) is there a better quality replacement/can i buy one that is higher rated?

sorry for all of the questions, i know enough to be dangerous but not enough to really know what i am doing when it comes to capacitors.

here is the info i see on the capacitor:
NGM Made in Mexico
233-280 MFD 250 VAC 60Hz
OP. T. Max 65 C Lot: 61078393
30/01/2006 08:04
C103237310607

thanks
jason

 

[A_Pmech]

Capacitor failure is inevitable. Could it be a sign of motor trouble? Yes, but not always. It's a good idea to make sure the centrifugal starting switch is working correctly. If it sticks in the closed position, start capacitors won't last very long.

The capacitor is a start capacitor. Any capacitor meeting the capacitance value range and at least 250V will work fine.

 

[larry_g]

Capacitor failure is inevitable. Could it be a sign of motor trouble? Yes, but not always. It's a good idea to make sure the centrifugal starting switch is working correctly. If it sticks in the closed position, start capacitors won't last very long.

The capacitor is a start capacitor. Any capacitor meeting the capacitance value range and at least 250V will work fine.

Lets highlight this in red. Massive failure like that is not normal failure. Normal failure would be a bulge or small vent, not spilling its guts out. This could also be other things like the pump demanding to much power that the motor does not get turning fast enough to throw out the start switch. I would monitor things when you replace the cap to see how it is operating.

lg
no neat sigline

 

[LS6 Tommy]

When you say "the breaker tripped" do you mean the plasma cutter breaker, the compressor breaker or that both the plasma cutter & the copmpressor share the same breaker?

Tommy

 

[Rookie2]

http://www.surpluscenter.com/Electrical/Capacitors/

 

[wuntunearlybko]

When you say "the breaker tripped" do you mean the plasma cutter breaker, the compressor breaker or that both the plasma cutter & the copmpressor share the same breaker?

Tommy

the compressor's breaker tripped, the plasma is fine. i was cutting along fine, mid way through the cut the compressor kicked in to build pressure back. i finished cutting and the compressor was still going when all of a sudden it just quit. i went upstairs to investigate and thats when i saw what looked like oil dripping from the top of the motor. i decided to put things up and let things cool down so i left it overnight (turning off the main panel when leaving). the next day, monday i went upstairs and found it looked like it exploded.

i just bought a large blast cabinet i have been using a lot lately. would overusage cause a failure like this? it says it is rated 100% duty cycle but maybe that isnt true.

thanks for the info, i will order a new cap and replace. hopefully this isnt a sign of other failures.

jason

 

[LS6 Tommy]

As memtioned, check the centrifugal switch, starting load amps, run load amps. You just want to make sure something didn't cause the cap failure and that it was just a shot cap.

Tommy

 

[wuntunearlybko]

i dont have any major testing tools, can i use a regular multimeter to test the starting amps?

is there a standard procedure to check the centrifugal switch?

jason

 

[wyliesdiesels]

i dont have any major testing tools, can i use a regular multimeter to test the starting amps?

is there a standard procedure to check the centrifugal switch?

jason

no. U need a clamp meter. Most multimeters will only test to about 10a....even if the motor pulled 10a, u wouldnt want to run that through the multimeter because of in-rush current...

 

[wuntunearlybko]

http://www.surpluscenter.com/Electrical/Capacitors/

so i was looking for replacements this morning and went to the above link, is it me or do they not have 233-280 rated MFD capacitors? i looked on a couple of other websites last night and did not see the 233-280 range caps in the 240v series, only in 120v.

jason

 

[Charles (in GA)]

Unless you are out in the sticks, you should easily be able to find the capacitor locally. Check with appliance parts and repair places, local Grainger, local electrical supply house, or electric motor repair shop.

If you have a motor repair shop locally, I'd take the motor to them and let them run it on the bench and if OK, buy a cap from them and be done. Money well spent.

Charles

 

[pattenp]

You just need to know where to look....
Google "motor start capacitor"

http://www.galco.com/buy/NTE-Electronics/MSC250V233

http://www.globalindustrial.com/p/m...220-250-volt-start-capacitor-233-280-mfd-233c

 

[wuntunearlybko]

Unless you are out in the sticks, you should easily be able to find the capacitor locally. Check with appliance parts and repair places, local Grainger, local electrical supply house, or electric motor repair shop.

If you have a motor repair shop locally, I'd take the motor to them and let them run it on the bench and if OK, buy a cap from them and be done. Money well spent.

Charles

thats a pretty good idea. i am typically too much of a DIY'er but that would help ensure it is done right. i actually live in Senoia, ga... not quite as far south as you. you wouldnt have any shops you trust would you?

jason

 

[G_P]

Definitely make sure the centrifugal switch is opening while the motor is running. Otherwise your new capacitor will blow its guts out within minutes.

 

[wuntunearlybko]

thanks guys for the input. i am glad i decided to take it to a shop. they called me just now and said the windings are touching and shorted out. it would have to be re-wound which is gonna cost about $400.

so now i am in the market for a decent quality motor. any suggestions? i dont mind spending a couple hundred bucks but if it gets too expensive i may be better off buying a new compressor.

jason

 

[abk241]

thanks guys for the input. i am glad i decided to take it to a shop. they called me just now and said the windings are touching and shorted out. it would have to be re-wound which is gonna cost about $400.

so now i am in the market for a decent quality motor. any suggestions? i dont mind spending a couple hundred bucks but if it gets too expensive i may be better off buying a new compressor.

jason

The motor shop you went to would have (should have) told you whether or not is is more cost effective to replace the motor or rewind.
Since they did not...ask.

 

[pattenp]

You can get a decent new 5HP motor for $250-$300.

http://www.amazon.com/dp/B007ATNHS6/?tag=atomicindus08-20
or
http://www.amazon.com/dp/B0009W8SBC/?tag=atomicindus08-20

 

[wuntunearlybko]

not to keep beating a dead horse here but i want to make sure i am buying a replacement motor that will work. i found this puppy at surplus center and it looks like it will work but i the only thing i am worried about is the pulley. i am pretty sure the emerson motor is 7/8" shaft but can anyone definitely verify? also, i cant remember if these motors turn CW or CCW

http://www.surpluscenter.com/Electr...PM-US-MOTORS-AIR-COMPRESSOR-MOTOR-10-2621.axd

also i am open to any other suggestions or recommendations. with that being said i do not want to drop the coin for a baldor or dayton motor at this time. i just need to get my compressor running again.

jason

 

[mikester]

Isnt there a toll free number for parts and service in the paperwork that came with your compressor ? I just replaced one in my CH single stage that I bought new back in 1999. CH had them in stock and I had it in 4 days. Think it was around $30.