Does your Yong Heng compressor cycle on and off while filling an air tank? Mine does and I didn’t know that was one of it’s “features.” I’ve had it a couple of years now and it just began doing this.
Yong Heng cycling
- Thread starter MikeAllen
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Sounds like you have a loose connection of one of the electrical terminals. Unplug it, take the cover off and check all the connections.
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All the vibration probably loosen some wires. Some Compressor will auto stop to purge or wait for it to cool down before restarting. The yong heng doesn't have this feature. So it should not be auto cycling.
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It could be a loose connection, the relay could be overheating and opening up, the on off switch could be at fault or it could have a thermal reset switch to protect the electrical system from over heating and causing a fire.
If it is tripping a thermal switch the unit not going to last much longer.
With two years of use it could be tripping a thermal switch, if it has one, because it is loading up because the second stage piston rings have deteriorated, melted, and are causing a serious load on the motor.
If it is tripping a thermal switch the unit not going to last much longer.
With two years of use it could be tripping a thermal switch, if it has one, because it is loading up because the second stage piston rings have deteriorated, melted, and are causing a serious load on the motor.
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No loose wires and no air leaks. I think I'll order another one so I can keep shooting and in the mean time tear this one down and try to rebuild it. I'm not in the mood to buy an Alkin or an Omega Turbo right at the moment!
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I'm pretty sure replacing the relay has solved the problem. I put a new relay in and filled my 9L/88cf SCBA tank from 200 BAR to 250 BAR without any stops or stalls. It ran for 9 minutes straight. Prior to replacing the relay it would have stopped and restarted several times in 4-5 minutes. Checked the old relay and it had no discolored or burned contacts so I suspect it had a weak coil. So - problem solved for now!
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It could be running too hot. There is a thermal switch on them. As far as I know the only other thing that could be automatic is the turn off switch when it reaches a preset pressure. When this is reached it will shut off, BUT, it won't restart again. There is nothing on the machine that would be automatic.
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My understanding is that this compressor does not have a thermal cutoff switch and it never did overheat. As I said I'm pretty sure it was the relay. Thanks for your comments!
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Yong Heng has begun cycling again. Runs for a couple of minutes then cuts off - after 15-20-30 seconds it starts again by itself. I’ve replaced the relay again and also replaced the automatic cutoff air gauge - still happens. All wires are tight. Yong heng does not have a thermal cutoff and temps are low. Any thoughts?
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If you're good with a multi meter...
I'd be curious to know how many amps the motor is drawing just before it cuts out?
I'm not sure if the Yong Heng motor is internally protected but many electric motors I've dealt with have a thermal cutoff switch embedded in their copper winding's that will trip or open to protect the motor when the internal winding temperature gets too high (i.e. motor draws too many amps) and then automatically reset when they cool somewhat.
If you can isolate just the motor leads, and immediately after the unit cycles off and is unplugged, ohm them out to see if they have continuity that will rule out the motor's internal thermal protection.
I'd be curious to know how many amps the motor is drawing just before it cuts out?
I'm not sure if the Yong Heng motor is internally protected but many electric motors I've dealt with have a thermal cutoff switch embedded in their copper winding's that will trip or open to protect the motor when the internal winding temperature gets too high (i.e. motor draws too many amps) and then automatically reset when they cool somewhat.
If you can isolate just the motor leads, and immediately after the unit cycles off and is unplugged, ohm them out to see if they have continuity that will rule out the motor's internal thermal protection.
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Good idea - I’ll try that at my next opportunity, but I’ve decided to stop messing with it for now. I have another one - same model and newer - that is behaving so far! If I get bored enough I’ll try what you are suggesting. Many thanks!
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I did try one more test. I ran the compressor under no load. It did cut off after about 4-1/2 minutes - then restarted by itself. Under load it cuts off after about 1-1/2 minutes. I think your theory is correct - heat buildup in the motor. Less heat buildup with no load. I think I’ll consider this one a parts machine and operate the newer one until it also fails, then buy a better compressor. I won’t buy an Alkin or Bauer - other than those, any suggestions? I mainly top off a 9L/88cuft cf bottle.
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