Here's one my compressor motor as a guard on it and a arrow stating which way the belt should run but my motor goes the opposite way....the compressor works up pressure to 120psi then shuts off but when I release some pressure down to about 90psi it should kick back in but the motor seems to just freeze and then it trips out....I know it a strange question but is the motor running the wrong way as to the direction of the arrow....as I look at the cage the motor is to the right and the air cylinder head is on the left....arrow points to the right....but the belt spins left....
- Thread starter mef3232
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Cobbler
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Some motors will start & run the wrong way if the capacitor is duff. I was asked to repair a garden shredder for a friend that would not cut anything at all. The local garden tool shop had looked at it decided it was scrap as they could not suss out why it didnt work. I pulled it apart & realised it ran backwards, then checked the capacitor with a meter & found it open circuit. I went to the local rewind place paid about £8 & cured it. The man in the rewind shop said some motors will start without the capacitor, but needs a run capacitor to work properly. If you can take the belt off, spin the motor so it starts the correct way & this may give you a clue.
Cobbler
Cobbler
Cobbler
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Hi there, if you have a multimeter, an old style one is easiest, but a digital will do, select the highest reading ohms scale & put it across the capacitor leads, (disconnect it first) you should see it charge up from the meter battery then show open circuit as is fully charged, then reverse the leads, you should see another reading as it discharges & recharges the opposite way. If you get no reading, ie: open circuit & shows no initial charge, the chances are its duff.
You may already know this, if you do, disregard my ramblings! Let us know the outcome.
Regards
Cobbler
You may already know this, if you do, disregard my ramblings! Let us know the outcome.
Regards
Cobbler
Cobbler
Codger bodger
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When I repaired the shredder on the previous post, just for interest I looked on the manufacturers spares list. Yes they listed a capacitor, price £80 nearly the price of a new shredder. I told this to the man in the the rewind place, his comment was "there having a laugh! £80 for that, it's the cheapest you could get, that's why it went"
Cobbler
Cobbler
KemppiFrog
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Another obvious question.. If the motor starts and then cuts out at 120psi, then freezes on a restart. Is the unload valve working? Try venting the entire load, then restart. If it does, then look at the valve.
Another prob with a sculptor friend. Long skinny extensions. He burned his motor by using it out in the field behind his house. The wire section was not enough for the start amps, so the motor never got past the high amp starting load.
Hi update tested the capacitor as theres only one and its ok....now I dont think its running the wrong way because when I put my hand when the pump is its getting loads of air to the pump.....the problem now is the non return valve is not working because it is stopping the motor kicking back in ....ie theres still pressure at the pump head stopping the motor from turning but when I empty the tank it will kick back in.....ive took the non return valve apart and sanded the rubber down flat so it sits property but its still the same.....HELP.....
rtbcomp
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It won't be the non return valve (NRV), it'll be the unloading valve in the switch.
If the NRV sticks open you'll get a continuous stream of air out of the unloader with the knob on the pressure switch set to "off". If the unloader doesn't open you won't get the brief hiss when the pump stops.
You should be able to tell from the lie of the blades on the pump pulley whether or not it's going round the right way.
If the NRV sticks open you'll get a continuous stream of air out of the unloader with the knob on the pressure switch set to "off". If the unloader doesn't open you won't get the brief hiss when the pump stops.
You should be able to tell from the lie of the blades on the pump pulley whether or not it's going round the right way.
Hi I do get the big hiss when it stops and the pressure switch is brand new.....I pulled the non return valve apart spring is very weak because when I blow down I with my mouth with the pressure switch outlet blocked off it leaks air so ive replaced the spring with a stronger one see if that works tomorrow.......now I need some brass olives to put the pipe from the compressor pump to the non return valve to the tank.....
rtbcomp
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Have a look here.
http://www.mig-welding.co.uk/forum/album.php?albumid=900
The spring is quite weak. Strengthening the spring could have an adverse effect.
As long as the unloader valve is open there will be no pressure in the delivery pipe to impede the pump.
Pump the tank up to pressure and disconnect the unloading pipe, there should no no air escaping. Try restarting the pump, if it starts OK with the unloading pipe disconnected you may have the wrong type of unloading valve in the switch.
There are two types, delayed and non-delayed. The former closes when the pressure in the delivery pipe reaches about 20 psi, giving time for the pump to get going.
The non-delayed closes almost immediately, with these there is usually another relief valve on the after-cooler which bleeds air to atmosphere until the pressure reaches 20 psi.
http://www.mig-welding.co.uk/forum/album.php?albumid=900
The spring is quite weak. Strengthening the spring could have an adverse effect.
As long as the unloader valve is open there will be no pressure in the delivery pipe to impede the pump.
Pump the tank up to pressure and disconnect the unloading pipe, there should no no air escaping. Try restarting the pump, if it starts OK with the unloading pipe disconnected you may have the wrong type of unloading valve in the switch.
There are two types, delayed and non-delayed. The former closes when the pressure in the delivery pipe reaches about 20 psi, giving time for the pump to get going.
The non-delayed closes almost immediately, with these there is usually another relief valve on the after-cooler which bleeds air to atmosphere until the pressure reaches 20 psi.
Here's my compressor....
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Can anyone tell from the picture of the fan pulley which way it should travel....its goes to the left....
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thanks
Hi thanks I think ive got a delayed uploading valve....ie when the pressure reaches 120psi I get a big hiss and it carrys on for about 10secs then when I release some air out down to 90psi the compressor kicks back in with no problems or pressure on the pump head.....hope it lasts......and again thanks......
