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Need help narrowing down issues with Craftsman air compressor

GLPStandard

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Hello everyone. I am new here and an electrical *****, but I will try to explain everything and understand any advice given. I am from the US but currently living in Germany where they obviously use 220V 50hZ. I recently purchased a mid 2000s Craftsman 30 gallon compressor with a Weg 110v 60hZ single phase motor.

The gentleman I bought it from brought it over from the US. He stated he used it dozens of times in the US with no issues but when he plugged it in here through a step down converter the garage breaker kept tripping. After 3 or 4 times resetting, the start capacitor blew, white smoke, nasty smell, and the compressor was dead.

Rather than fix it, he decided to sell it and for $50 I figured why not. I bought a new start and run capacitor and switched both out. I also bought a 3000W converter which should be plenty to run the 110v @15amps. I had identical issues as him. This time the start capacitor literally blew up and the house breaker tripped.

I started suspecting maybe he had the capacitors hooked up in place of one another, so I took the end cap off the motor and traced the wiring. They were hooked correctly, so now I am thinking maybe the centrifugal switch isnt opening at speed to disconnect the start capacitor, causing it to run constantly and overheat.

I moved the switch by hand and it does feel a bit weird. It doesnt make the characteristic snap back into place when you release it. It sounds a bit squeaky and sluggish. So this is what I suspect though like I said, I'm an idiot and know very little about how these work and even less about electricity.

So my questions are, am I on the right track? What further diagnosing can I do? How do I know what I need as far as a replacement centrifugal switch? How do I replace the switch? There is a bearing on the end of the shaft that I can't see how to remove so I dont know how I would remove the old switch.

I did check continuity of the start switch (I think that's what its called) and it is working fine.i thought to run the motor with two run capacitors just for 5 or so seconds with the end plate off to watch the centrifugal switch and see if it opens at speed but I wasnt sure if this is safe for me or the motor, or if I would need to remove the compressor piston side first.

Any advice you can give is appreciated.
 
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laser3kw

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by converter you mean step down transformer? Big stupid transformer - no electronics?
is this a belt drive pump or a "direct drive" pump where the reciprocating parts attach directly to the motor shaft?
 
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GLPStandard

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by converter you mean step down transformer? Big stupid transformer - no electronics?
is this a belt drive pump or a "direct drive" pump where the reciprocating parts attach directly to the motor shaft?

Correct. I meant transformer. So it converts 220v to 110v. The pump is a direct drive so everything is attached as one piece. No belt.
 

vavet

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I don't know if I can be much help, but maybe.

I just sacrificed a 1999 Craftsman oil free compressor because the tank was suspect. The pump, motors, capacitors, switches, etc are all operational.

I'd give you the parts, but I'm not sure the shipping costs to Germany would be cost-effective vs you buying new. If we determine the parts match and you need some static electrical reading off of something, I can help with that.
 
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GLPStandard

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I don't know if I can be much help, but maybe.

I just sacrificed a 1999 Craftsman oil free compressor because the tank was suspect. The pump, motors, capacitors, switches, etc are all operational.

I'd give you the parts, but I'm not sure the shipping costs to Germany would be cost-effective vs you buying new. If we determine the parts match and you need some static electrical reading off of something, I can help with that.

Since I'm active duty military, I have an APO address here in Germany which is considered a US address. Shipping through USPS is the same to here for me as it is within the US. With that said, if we can narrow down the problem, and I have to pay for you to ship me some parts, I'd definitely be appreciative.

I'm going to try to take some photos so maybe we can see if any of the parts you have would be compatible. I'd really like to get this compressor working, but don't want to spend a fortune doing so. I'm already into it about $90 not including the transformer, so another $50 or so is all I'd be willing to spend before I call it a loss.

If the centrifugal switch you have in your spare motor is the same as in mine, I'll definitely take it if you don't mind. Hell, if shipping is cheap enough (less than $30) ill take the whole motor assuming they are the same or similar.
 
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GLPStandard

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I don't know at what shaft speed the switch should drop out, but that motor will only run at 83% of its intended speed on 50 Hz power.

Great info. See I told you I'm not electrically savvy. Sounds like that could be an issue since he said it worked fine in the US but not here. Would it be best to replace the switch with a lower rpm switch or see if I can find a hz converter?
 

Vahispd

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Interesting discussion. There was a thread recently that really opened up a compressor motor for reference. "https://www.garagejournal.com/forum/showthread.php?t=473006"

I presume your step-down transformer only changes voltage and not frequency?
 

walta

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It is a wild guess but I think the voltage converter you are using is way too small to do the job. Yes I understand the label on the converter says it can do the amps the motor label says it needs. It has been my experience that converter labels overstate the converters capabilities by 300%. It has also been my experience that hard to start motors like compressors need a power source capable of supplying twice the motors running load to get moving.

In short to run the motor you need a converter with a label 6 times the motors rating.

I would guess the converter will weigh about the same as the compressors motor.

I think the smart move is buying a German compressor and sell it when you get new orders.

Walta
 

The Cobbler

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I suspect its due to the starting amps of the motor & too small a transformer.
taken from the net
The current at motor starting can be anywhere from 5-8 times the motor's full load. Any electrical system is designed to carry and sustain a steady state during the running period. However, motor starting will cause electrical cables to carry a higher current compared to the steady-state
 
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GLPStandard

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It sounds like this motor just wont work for me while I am in Germany. Replacing the motor with a 50hz 230v motor is too costly. I do have one option though, if it will work and is worth the effort..

I have another Craftsman compressor from 1997, 20 gallon. I bought the 30 gallon as an "upgrade". The 20 gallon I have has a GE motor with the following specs:

60hZ, 115v/230v, 56Z frame, single phase, 3450RPMs

I've ran this compressor wired for 230v for the last 3 years with no issues. Is it feasible and worth the effort to change this motor to the 30 gallon tank/compressor? The Weg motor is a 56E frame (not sure what the letter means or what the difference is).

I think in going to swap the GE motor to the 30 gallon compressor, and store the 20 gallon compressor and Weg motor until I move back to the US, at which time I'll swap them back and sell the 20 gallon.

Is it even worth it to swap the motor for the extra 10 gallons? Are there any concerns with compatibility? Should I swap the compressor piston, fan and motor over as one unit or just swap the motor?
 

dogdog

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Not an expert in motors but the capacitor require for the same motor running 120V/50Hz is different from 120V/60hz single phase...

you can find the calculators on line, but not even sure how to get the run capacitor value.. probably the same way. if you play around with the values, you'll see the capacitance required for a 50hz is higher than the 60hz ...

I just remember there was a thread few years back about a guy from Columbia that group buy a special screw compressor or something and wanted the motors to run 120V... he end up having to find a "friend" that have all size available and test each until he gets the motor to run.. might not be your case or worth the effort $$$$.
 

PCustoms

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Is it even worth it to swap the motor for the extra 10 gallons? Are there any concerns with compatibility? Should I swap the compressor piston, fan and motor over as one unit or just swap the motor?

Don't swap anything!

Plumb the 20 into the 30, using the 30 as a big, dumb tank. If you need to "undo" anything it's just disconnecting a few hoses.
 
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BillK

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I dont know what you are doing with the compressor but I really dont see much advantage with the 10 extra gallons. T home I have an ancient 20gal 2 1/2 hp Craftsman compressor I bought in 1973 and it has done everything I have ever needed at home, including painting a complete car years ago.
 

vavet

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Since I'm active duty military, I have an APO address here in Germany which is considered a US address. Shipping through USPS is the same to here for me as it is within the US. With that said, if we can narrow down the problem, and I have to pay for you to ship me some parts, I'd definitely be appreciative.

I'm going to try to take some photos so maybe we can see if any of the parts you have would be compatible. I'd really like to get this compressor working, but don't want to spend a fortune doing so. I'm already into it about $90 not including the transformer, so another $50 or so is all I'd be willing to spend before I call it a loss.

If the centrifugal switch you have in your spare motor is the same as in mine, I'll definitely take it if you don't mind. Hell, if shipping is cheap enough (less than $30) ill take the whole motor assuming they are the same or similar.

As a fellow GJer and veteran, I'm happy to help if I can.
Let me know because I got a PM from another GJer expressing interest in case you don't want them.
The model number on my compressor is 919.165230. The switchbox has a part number of AC-0385-1. The motor's model number is 5KCR49TN2312CX.
 

frank001

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It is a wild guess but I think the voltage converter you are using is way too small to do the job. Yes I understand the label on the converter says it can do the amps the motor label says it needs. It has been my experience that converter labels overstate the converters capabilities by 300%. It has also been my experience that hard to start motors like compressors need a power source capable of supplying twice the motors running load to get moving.

In short to run the motor you need a converter with a label 6 times the motors rating.

I would guess the converter will weigh about the same as the compressors motor.

I think the smart move is buying a German compressor and sell it when you get new orders.

Walta

^^^^This 100%^^^^^:rocker:
 
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GLPStandard

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As a fellow GJer and veteran, I'm happy to help if I can.
Let me know because I got a PM from another GJer expressing interest in case you don't want them.
The model number on my compressor is 919.165230. The switchbox has a part number of AC-0385-1. The motor's model number is 5KCR49TN2312CX.

Tried to send you a PM but it wouldnt let me

By any chance is the motor dual voltage? I searched the model number and found some that were and some that werent. If its capable of 230v I would definitely take it depending on shipping costs.

How large and heavy of a box do you think it would be? I can get a shipping quote and see if it would be reasonable.
 
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GLPStandard

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^^^^This 100%^^^^^:rocker:

I've definitely considered it but all of the hobbyist compressors in Germany I've seen are very small (around 20 liters). I think the largest I've seen is 50l. Unfortunately Germans just dont do the same type of DIY garage work as Americans so there is no market for a decent hobbyist air compressor. I could get an industrial 80 gallon compressor but it would be several thousand dollars. There really is no in between.
 

dogdog

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I've definitely considered it but all of the hobbyist compressors in Germany I've seen are very small (around 20 liters). I think the largest I've seen is 50l. Unfortunately Germans just dont do the same type of DIY garage work as Americans so there is no market for a decent hobbyist air compressor. I could get an industrial 80 gallon compressor but it would be several thousand dollars. There really is no in between.

I am not sure where you are in Germany... I followed and enjoy watching this guy "Post Apocalyptic Inventor" who repair/fix/rebuild a lot of "German" stuff including motor and electronics. Maybe send him a message, see if he is close by to help you figure out what capacitor(s) to use for your WEG to make it work for "German" electricity... or sell you a functional motor he got.



 

vavet

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Doesnt look like a dual voltage motor to me, but maybe the hive mind here can help. The switch is marked with both ratings.
I’ll get an estimate on the weight for you.
 

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vavet

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Tried to send you a PM but it wouldnt let me

By any chance is the motor dual voltage? I searched the model number and found some that were and some that werent. If its capable of 230v I would definitely take it depending on shipping costs.

How large and heavy of a box do you think it would be? I can get a shipping quote and see if it would be reasonable.

The weight of the pump, motor, and switch box is 38lbs using my bathroom scale. As luck would have it, we got an amazon delivery of cat food yesterday so I have an 18 x14 x 9" box that would work. It might be a few days before we get another amazon delivery! ;)
 
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GLPStandard

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I am not sure where you are in Germany... I followed and enjoy watching this guy "Post Apocalyptic Inventor" who repair/fix/rebuild a lot of "German" stuff including motor and electronics. Maybe send him a message, see if he is close by to help you figure out what capacitor(s) to use for your WEG to make it work for "German" electricity... or sell you a functional motor he got.




Thank you I will definitely send him a message
 
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GLPStandard

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The weight of the pump, motor, and switch box is 38lbs using my bathroom scale. As luck would have it, we got an amazon delivery of cat food yesterday so I have an 18 x14 x 9" box that would work. It might be a few days before we get another amazon delivery! ;)

Pm sent
 

dogdog

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Doesnt look like a dual voltage motor to me, but maybe the hive mind here can help. The switch is marked with both ratings.
I’ll get an estimate on the weight for you.


The switch is capable of dual voltage as most of them are DPST... means they care capable of switching off/on both the L1/L2 or Line/Neutral at the same time

The motor, unless there are some undocumented features,unless he is inquisitive enough to dig out the connections and change the winding arrangements...

It is 120V/60HZ hardwired and most likely result in the same... dunno but one thing for sure it is still 60HZ... Might needed new caps.

Another route is try call WEG support number and see if they are willing to "suggest" a capacitor value to try. that dependents on his social phone skills...
 
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