Hi Tatro, The motor will have a centrifugal switch behind the fan which switches between the start capacitor and the run capacitor. Either the switch has bad contacts or the run capacitor/s is on the way out. The fact that it runs intermittently would suggest it is the switch. This would also cause the thermal switch to keep tripping.
I actually work on air compressors for a living. The "circuit breaker" on the motor is usually a thermal over load. If the motor is getting really hot, its tripping that thermal over load, but you will be able to reset the overload once the motor cools. The reason your pump has pressure stuck in the head is you are turning the machine on and off at the magnetic starter. Your pressure switch should be what is turning the machine on and off, and If the contacts on your pressure switch are never opening / closing, then the little unloader valve on the switch is never actuating and bleeding off the residual pressure in the head / copper discharge tube. The clacking noise you are hearing in the motor might be the centrifical switch which is usually located in the back of the motor, which switched the motor between the "start" windings and the "run" windings. Get a multi meter with an amp clamp on it, and put it on the motor power wires and see how much amperage the motor is drawing when its running then compare it to whats specified on the motor tag under "SFA (service factor amps) or FLA (full load amps). Hope this helps?
it is not the compressor or the switch because it makes the same noise as it is running. it just makes that same noise on the start too. the motor is running very hot so i am thinking it is more in the commutator or brushes. the armature might have a fried leg or two? its coming apart soon to see what i find. i don't like running things until they are done. tatro
@@TatroMachine Do not quote me, but this motor does not have brushes in it. I know a limited amount about motors however, just enough to get peoples machines back up and running. Keep us posted on what you find. I am going to double down and say the motor centrifugal switch contacts have welded together and its stuck running off of the "start" windings. Good luck.
@@jontest5718 The switch welded closed or the flyweight stuck or broken is a possibility. That would leave the start windings on during run and trip the overload in a couple seconds.
You might wanna double check the capacitors again, 1 should be for start up then 2 for run, I had a issue with a small 220 unit it had the wrong cap, would get hot, double check the wiring on them I seen you have a schematic but you never know, the clicking sounds like the breaker kicking on, it's so loud on video you can't tell, hope ya figure it out, also remember to drain the tank they can get a lot of water in them
Check the starter contacts. It’s the little green box with the nut on top. Turn power off and unscrew the nut that on top. Lift off cap and check to make sure contacts aren’t stuck together. It happens very frequently.
it starts just fine. it is the high amp draw and heat build up that is the problem. there is a noise that you can here on the hit of the start. that happens as it runs too but i can't tell what it is. you would think the viewers would have know that i was turning the compressor on and off to show the noise that i was describing. obviously the starting was not the problem. tatro
I also work on compressor for a living . George and john have brought up exactly what i would start with noise is from the start clutch in motor . Might be a good idea to test mfd of caps in motors . But the first thing i would look at since you still have head pressure is the check valve between your compressor head and your tank . Your back feed pressure to the head witch creates a very hard start for the motor . Typically when that happens the motor will trip the circuit immediately. Might even be the something going on with the unloader leaving head pressure in the compressor head. More that likely the check valve has carbon build up not allowing the ceramic disc to seat . Some valves have a snap ring . So you can pull them apart and clean them . Others will have to be replaced . Most compressors repair shops in the area should stock the valve .
it is not the compressor because it makes the same noise as it is running. it just makes that same noise on the start too. the motor is running very hot so i am thinking it is more in the commutator or brushes. the armature might have a fried leg or two? its coming apart soon to see what i find. i don't like running things until they are done. tatro
The check valve might be leaking and the motor is having to start spinning the compressor against full pressure. That or the regulator isn't bleeding off the pressure when it shuts down.
I have been told bad caps can cause an electric motor to overheat and trip the protection. After checking for mechanical binding in the compressor and motor, you might test the caps. You can test an electrolytic capacitor by shorting the terminals together to discharge it. (Be careful, they hold quite the charge) then attaching an ANALOG meter to it. Set it to ohms, so you are running off the meter battery and touch one terminal to each cap terminal. Then, reverse them and do it again. If the cap is good, the reading should go higher the second time.
I ran into a similar situation a while back with a Dayton motor, and it turned out to be the bearing on the pulley shaft was ceasing and overheating the motor and kicking the breaker. Just a thought.
It looks like it's plumbed without an unloader valve? The check valve is probably the fitting where the copper line from compressor connects to the flex hose. I was cringing very time the motor restarted. You're not supposed to start a compressor duty electric motor that often.
@@TatroMachine If you're gonna take it apart replace the bearings and check the windings with an ohm meter. I suspect as others have suggested you have a check valve or unloader valve problem. Kind of like kick starting a Harley that's out of time. I have the same compressor, mine is a bit newer tho.
Pull the back cover off and then the fan and the Centrifugal switch should be behind that. Check/clean the contacts. If they are OK then its probably the run cap/s.
@@TatroMachine I'd pull the cooling fan and the dust cover behind it and have a look at the start points anyway. The contacts welded shut or the flyweight assembly misadjusted can cause the problems the compressor is having. Although usually the start cap gets murdered first.
Take the belt off, spin the compressor by hand with the discharge pipe disconnected. Resistance on drive pulley? Bearing noise? Run/spin by hand the motor absent the compressor, noise? Motor should run forever absent the compressor.
If the motor is heating up , could be a few things , loose wire , bad wire end , dirty contacts , stuck brushes if it has brushes or wore out brushes , the kick on and off switch , armature or field problem , bad breaker , bad thermal switch usually in the armature , bad reset switch , maybe you have some electrician buddies you can get to check it , amp draw and etc....... You have to have a compressor no way around that .......
Take belt off electric motor check shaft with your hand for side to side movement and noise, if so bad bearings replace motor.. with belt off turn on power to electric motor and see if it still trips breaker. If so, replace motor. With belt back on motor turn on motor and check amp draw on a hot leg if it exceeds FLA (full load amps) there’s a problem that’s a few quick checks. While you have the belt off, turn the pump pulley make sure it’s not seizing up and make sure you have oil of course in it,,as you well know sometimes a motor won’t trip the breaker free of resistance but once you add the resistance with belt and pump, it will trip breaker if windings are going bad or the pump is dragging down the motor
Does it have a centrifugal switch to switch from start windings to run windings in the motor? If so it may have a failure in the run windings contacts.
how would you know. you have no idea what is wrong with it just like i don't. what i do know is that what is wrong is in the motor and not the pump or external parts. tatro
@@TatroMachine Your right, I don't know what is wrong. But I do have +50 years of on the job experience fixing what other people have broken. The compressor is supposed to be unloaded "easy to turn" when first starting, so the motor gets a running head start and up to speed. First thing I would do is use a clamp on amp gage, to check the running current, then take the belt off and see how many amps the motor pulls without a load. The 7.5hp motor should pull around 22amps at full load if everything is right and less than 7ish amps under no load.
that would be a good test if i had that kind of meter. i do think it has a heavy amp load going in because of the heat build up in the motor. its coming apart so that i can see what is wrong, instead of guessing. most of the time you can see what is wrong with things when all the parts are in front of you. tatro
![เขามัทรี - เอ็กซ์ ศุภกฤต - จอนนี่มิวสิค [ Official MV ]](http://i.ytimg.com/vi/AS9ufKuQIVs/mqdefault.jpg)
Hi Tatro, The motor will have a centrifugal switch behind the fan which switches between the start capacitor and the run capacitor. Either the switch has bad contacts or the run capacitor/s is on the way out. The fact that it runs intermittently would suggest it is the switch. This would also cause the thermal switch to keep tripping.
maybe but i don't think so. we will see soon.
tatro
I actually work on air compressors for a living. The "circuit breaker" on the motor is usually a thermal over load. If the motor is getting really hot, its tripping that thermal over load, but you will be able to reset the overload once the motor cools. The reason your pump has pressure stuck in the head is you are turning the machine on and off at the magnetic starter. Your pressure switch should be what is turning the machine on and off, and If the contacts on your pressure switch are never opening / closing, then the little unloader valve on the switch is never actuating and bleeding off the residual pressure in the head / copper discharge tube. The clacking noise you are hearing in the motor might be the centrifical switch which is usually located in the back of the motor, which switched the motor between the "start" windings and the "run" windings. Get a multi meter with an amp clamp on it, and put it on the motor power wires and see how much amperage the motor is drawing when its running then compare it to whats specified on the motor tag under "SFA (service factor amps) or FLA (full load amps). Hope this helps?
it is not the compressor or the switch because it makes the same noise as it is running. it just makes that same noise on the start too.
the motor is running very hot so i am thinking it is more in the commutator or brushes. the armature might have a fried leg or two? its coming apart soon to see what i find. i don't like running things until they are done.
tatro
@@TatroMachine Do not quote me, but this motor does not have brushes in it. I know a limited amount about motors however, just enough to get peoples machines back up and running. Keep us posted on what you find. I am going to double down and say the motor centrifugal switch contacts have welded together and its stuck running off of the "start" windings. Good luck.
that is my #2 option too. i still think its in the armature area and brushes.
tatro
@@TatroMachine 99% of AC motors ain't got any brushes or commutator.
There's only a rotor.
@@jontest5718 The switch welded closed or the flyweight stuck or broken is a possibility. That would leave the start windings on during run and trip the overload in a couple seconds.
There’s a thermal switch within most motors typically wears out over time
You might wanna double check the capacitors again, 1 should be for start up then 2 for run, I had a issue with a small 220 unit it had the wrong cap, would get hot, double check the wiring on them I seen you have a schematic but you never know, the clicking sounds like the breaker kicking on, it's so loud on video you can't tell, hope ya figure it out, also remember to drain the tank they can get a lot of water in them
Just had the same problem. Turned out to be the bearing in the motor has gone bad. That’s why it’s getting so hot.
Check the starter contacts. It’s the little green box with the nut on top. Turn power off and unscrew the nut that on top. Lift off cap and check to make sure contacts aren’t stuck together. It happens very frequently.
no
@@TatroMachine No what?
it starts just fine. it is the high amp draw and heat build up that is the problem. there is a noise that you can here on the hit of the start. that happens as it runs too but i can't tell what it is. you would think the viewers would have know that i was turning the compressor on and off to show the noise that i was describing. obviously the starting was not the problem.
tatro
I also work on compressor for a living . George and john have brought up exactly what i would start with noise is from the start clutch in motor . Might be a good idea to test mfd of caps in motors . But the first thing i would look at since you still have head pressure is the check valve between your compressor head and your tank . Your back feed pressure to the head witch creates a very hard start for the motor . Typically when that happens the motor will trip the circuit immediately. Might even be the something going on with the unloader leaving head pressure in the compressor head. More that likely the check valve has carbon build up not allowing the ceramic disc to seat . Some valves have a snap ring . So you can pull them apart and clean them . Others will have to be replaced . Most compressors repair shops in the area should stock the valve .
it is not the compressor because it makes the same noise as it is running. it just makes that same noise on the start too.
the motor is running very hot so i am thinking it is more in the commutator or brushes. the armature might have a fried leg or two? its coming apart soon to see what i find. i don't like running things until they are done.
tatro
The check valve might be leaking and the motor is having to start spinning the compressor against full pressure. That or the regulator isn't bleeding off the pressure when it shuts down.
no
Test the check valve on the compressor.
I have been told bad caps can cause an electric motor to overheat and trip the protection. After checking for mechanical binding in the compressor and motor, you might test the caps. You can test an electrolytic capacitor by shorting the terminals together to discharge it. (Be careful, they hold quite the charge) then attaching an ANALOG meter to it. Set it to ohms, so you are running off the meter battery and touch one terminal to each cap terminal. Then, reverse them and do it again. If the cap is good, the reading should go higher the second time.
that was allready done in my last video before this one.
tatro
Yea you might as well pull it so you can check everything goin on with the motor like you said
I ran into a similar situation a while back with a Dayton motor, and it turned out to be the bearing on the pulley shaft was ceasing and overheating the motor and kicking the breaker. Just a thought.
that would be option two for me. option one is the armature commutator or brushes.
tatro
Shoot it with ir temp if it cuts out low replace switch that would cause the trip
Points in pressure switch pitted
Motor overheating, bad run cap or caps. That clack is the start capacitor clutch kicking out and I didn't hear the unloader valve either.
It looks like it's plumbed without an unloader valve? The check valve is probably the fitting where the copper line from compressor connects to the flex hose.
I was cringing very time the motor restarted.
You're not supposed to start a compressor duty electric motor that often.
the capacitors checked good so i am moving on to something else. i am moving on to the guts in the motor next.
tatro
@@TatroMachine If you're gonna take it apart replace the bearings and check the windings with an ohm meter. I suspect as others have suggested you have a check valve or unloader valve problem. Kind of like kick starting a Harley that's out of time. I have the same compressor, mine is a bit newer tho.
Starter contacts in the main box. Cheap and replaceable.
Pull the back cover off and then the fan and the Centrifugal switch should be behind that. Check/clean the contacts. If they are OK then its probably the run cap/s.
its not a starting problem. it is a running problem. you can just hear it on the start up.
tatro
@@TatroMachine I'd pull the cooling fan and the dust cover behind it and have a look at the start points anyway. The contacts welded shut or the flyweight assembly misadjusted can cause the problems the compressor is having. Although usually the start cap gets murdered first.
Take the belt off, spin the compressor by hand with the discharge pipe disconnected. Resistance on drive pulley? Bearing noise? Run/spin by hand the motor absent the compressor, noise? Motor should run forever absent the compressor.
If the motor is heating up , could be a few things , loose wire , bad wire end , dirty contacts , stuck brushes if it has brushes or wore out brushes , the kick on and off switch , armature or field problem , bad breaker , bad thermal switch usually in the armature , bad reset switch , maybe you have some electrician buddies you can get to check it , amp draw and etc....... You have to have a compressor no way around that .......
Take belt off electric motor check shaft with your hand for side to side movement and noise, if so bad bearings replace motor.. with belt off turn on power to electric motor and see if it still trips breaker. If so, replace motor. With belt back on motor turn on motor and check amp draw on a hot leg if it exceeds FLA (full load amps) there’s a problem that’s a few quick checks. While you have the belt off, turn the pump pulley make sure it’s not seizing up and make sure you have oil of course in it,,as you well know sometimes a motor won’t trip the breaker free of resistance but once you add the resistance with belt and pump, it will trip breaker if windings are going bad or the pump is dragging down the motor
i am going with the windings going bad or the brushes. we will see soon.
tatro
Does it have a centrifugal switch to switch from start windings to run windings in the motor? If so it may have a failure in the run windings contacts.
Take it apart as you said and look into it before it may break beyond repair.
that is the plan for now. i got the backup compressor down here yesterday.
tatro
Sorry no clue the compressors I worked on were gas engine powered the place I got parts from said that they were different from electric to ones
Is the tank filled or is it not filling ?
I think the problem would go away if the stroke on the pump was increased to a minimum 4-5/8" 😅
i already have the big stroker pulley on the motor. that pump is singing.
tatro
grease fitting been used lately?
nope, i don't know if it even has one. not where i can see them it there are any. its coming apart anyway.
tatro
@@TatroMachine Looked like a zerk fitting at 12 O:Clock on top of the front cover, painted green? @ 2:30
rod bearing
Bad bearing more than likely. probably the fan side of the bellhousing
i don't think so but i will be looking into that one soon.
tatro
The more I look, the more I think the compressor isn't plumbed right.
yes, that is why it has been working this way for decades.
tatro
It lasted for years being wrong, but now it's broken because of it.
how would you know. you have no idea what is wrong with it just like i don't. what i do know is that what is wrong is in the motor and not the pump or external parts.
tatro
@@TatroMachine Your right, I don't know what is wrong.
But I do have +50 years of on the job experience fixing what other people have broken. The compressor is supposed to be unloaded "easy to turn" when first starting, so the motor gets a running head start and up to speed.
First thing I would do is use a clamp on amp gage, to check the running current, then take the belt off and see how many amps the motor pulls without a load. The 7.5hp motor should pull around 22amps at full load if everything is right and less than 7ish amps under no load.
that would be a good test if i had that kind of meter. i do think it has a heavy amp load going in because of the heat build up in the motor. its coming apart so that i can see what is wrong, instead of guessing. most of the time you can see what is wrong with things when all the parts are in front of you.
tatro