Coltri MCH 11 minisilent motor trouble

[Vinge86]

The compressor wont start anymore. It blows the fuses both on the compressor and in the fusebox. 1 phase motor, 250v and 25A fuse.
We found out that the start capacitor was broken, so we replaced that, but it still wont start. The run capacitor is ok.
Have tried to start it without the belt, but it still does not start. Anybody got any tips on how to fix this? Is a new motor the only solution? In that case, where can i order a new one?

 

[BRT]

Does it hum before it blows the fuses or do they blow almost immediatly? Most single phase motors have a start switch to switch the start capacitor in and out of the circuit. It is usually a centrifugal switch under the end cap away from the shaft. If this doesn't work the motor will not start. If the motor hums you might try getting the shaft spinning and then turning the power on. If there is a problem in the start circuit it will start this way (just as a test of the start circuit)

I just noticed the motor is rated at 24 amps. It is going to take some good time delay fuses to make it start with 25 amp fuses. The motor will likely pull 75-150 amps momentarily while starting.

 

[Vinge86]

They are blowing almost immediatly. We have managed to start it on a slow 16a circuit earlier. Test ran it on 16a the day we got the compressor(didnt have a 25a circuit yet). The integrated fuse on the compressor blows aswell.

 

[Peter_C]

I would wire it up with #8 wire and a 40amp breaker. You should be able to take a volt ohm meter and test the motor for a direct short. Do a web search for how to do that.

 

[BRT]

If you can't start it on a 25 amp fuse you can't start it on a 16 amp with similar type fuses. It sounds to me like you have a short which could be in a burned winding. How does the motor smell? They stink when you let out the magic smoke. Could be in your wiring to to the motor. Are you sure the wiring to the capacitor is correct?

Blowing both fuses instantly sounds like a direct phase to phase short.

Are you 50hz 220 v in Norway? Shouldn't make a difference for testing at least.

 

[Vinge86]

Turnes out the windings is shorthed somehow. nothing looks burned, but i get 0,6 ohm when measuring the winding. There is no smell aswell.

Any tips for a good replacement motor? 230v 4kw 50hz 2850 rpm.


Sent from my iPad using Tapatalk HD

 

[iain/hsm]

Turnes out the windings is shorthed somehow. nothing looks burned, but i get 0,6 ohm when measuring the winding. There is no smell aswell.

Any tips for a good replacement motor? 230v 4kw 50hz 2850 rpm.

Sent from my iPad using Tapatalk HD

IMHO Your going to struggle finding a good quality 4Kw single phase motor as the best motor manufacturers don't do to 4Kw on a CSR 1ph motor.

And the motor may just be big enough to make it worth sending it to a motor rewind company for repair. Its a dollar and cents call.

But for an alternative replacement. Of the three best brands: ABB only go to 2.2 Kw and Siemens 3Kw
Brook Crompton also only offer 3Kw and 4Kw is special order min quantities.
The only available that do a 4Kw would be Leroy Somer but as a one off customer you will get hosed on the price.

The next option down would be the far east, or China and for that TECO motors offer a 4Kw as do TEC Motors, poorer quality but cheaper and easy availability in UK although not so sure in Norway

Forget the Yankee motors WEG, General Electric, or Baldor, Drip proof and American frame sizes will cause you too many problems.

However for around the same price as the China imports are the Italian, You have two choices Marelli motors or SOGA Motors both make a 4Kw 1phase cap start cap run motor on a 112 frame, and one of those you have already. Frankly I would try the Coltri importer they must buy enough SOGA motors in bulk to be able to replace this competitively. Iain

 

[Vinge86]

Iain, what do you think about mounting a 3phase motor and a VFD? Seems like its easyer to get hold of a 3phase motor.