Fan Motor Switch Tripping Problem in a Dehumidifier Kiln

Troubleshooting a fan performance issue in a dehumidifier kiln. October 15, 2010

Have a Nyle 200. It needed a new fan motor in the unit and we changed it and now have an issue with it tripping the switch on the controller. We put a brand new 1/3hp 240v single phase motor, same size - 1725 rpm, and it pulls 3.1 amps. It will turn on and run without the fan blade mounted. Once the fan blade is mounted it kicks out the switch. The blade is good, not bent, and the voltage is good. Iím not sure if anyone has had a similar problem, and if so do you have any answers? The motor checked out fine. It is brand new, and the cap is okay in the motor.

Forum Responses
(Sawing and Drying Forum)
From Gene Wengert, forum technical advisor:
Call Nyle and find out what the rating of the switch is. They are very helpful people.

From the original questioner:
I have. They are helpful, but everyone is stumped. We changed out the switch, have checked all the obvious terminals for loose wires and it still keeps kicking out the switch. It will run with no fan blade on, and as soon as you mount the fan blade it kicks the switch out. I think the overload on the switch is 5.4 amps. The fan is drawing 3.1 amps when running with no fan blade, and it kicks it out soon as you hit it once the blade is put on. The blade is on the right way and it is not damaged. Itís really getting frustrating. I have a load to dry and no dryer. There are a few refrigeration guys around us who work on compressors but no one who knows a lot about dryers. Any suggestions would be great.

From contributor L:
If it is drawing 3.1 amps without the fan on, I bet you have it wired for 115v. Most of those motors are 115/230 and if you connect incorrectly, that is what will happen. Check the label and double check the connections.

From the original questioner:
We did check the wiring and the rotation. I will double check again. Do you know how many amps it should draw without a load/fan? Have you ever seen a motor that was color coded wrong or labeled wrong? I have an electrician putting the motor in, and he is also completely perplexed. If the motor is new, wired right, the voltage is good, and the switch is good then where do we go next?

From contributor E:
Sometimes you just get a bad new motor. But most of the time, back-up and walk it through from the beginning. What started the onset to the breakdown (motor, switch, fan, old age, etc.), upon replacing? Is this motor all the same spec's as original or just close? Is it a factory replacement or aftermarket?

I'm more in agreement with the above posting. Somethingís not wired or connected correctly. If youíre wired 220 onto 110 the motor should be revving some rpmís but not for long. If there's a bad connection (corroded, loose, wire shorting) you can get some of your results you've mentioned and by adding the fan/load it shorts. I helped a man search his electric mill issues with his new motor and found he was shorting in the main breaker panel which caused the original failure.

From contributor L:
I have seen mislabeled motors but itís rare. Iíve seen more a lot more where a mistake was made. The amperage when running with the fan should be about what you are getting without the fan, if I understand your post correctly. With no fan on, I think you would get very low amps, less than one. I can have that checked if you are still having problems. You could always read out the ohmís for the windings as connected and call the motor supplier and see if it is correct.

From contributor U:
I have a Nyle 50 and I still have the original motor . It has seized up a couple of times I have taken it apart and freed up the bearings (bushings ). Are you sure the first motor was defective? Usually they would have overheat protection in the motor. I spent a bit of my working life doing troubleshooting.

I don't know if your contactor has adjustable amperage settings on the kickout. If it does, increase the amperage setting as far as it will go, temporarily. See if the motor will keep going. If it still kicks out you could have a defective overheat relay. Sometimes they get weak. Sometimes the points in the contactor can become defective. Sniff around the contactor see if there is a burning Bakelite smell. If all else fails, shut the power of to the unit . Wire the motor in directly. Restart. This will tell you if the motor is ok. Make sure the motor is not overheating as this might indicate a 120v motor hooked 240v. These are just temporary connections and not to be left that way. My Nyle 50 is rated 120v Ė Iím not sure about the 200. I have also been really happy with Nyleís backup when I have a problem.

From the original questioner:
Well, I think we may have it. I think the capacitor in my new motor was bad out of the box. It was causing the amps to be high. It was running 3 amps with no load and would spike past 5.5 with fan on and kick out switch. The original motor is toast. The armature went bad and blew up the cap. I do have to say that for us, Nyle has been a good company. I was going to order another motor from them today and the tech told me I could use one of the circ. fanís motors to replace it and get running. My friend and neighbor down the road have some larger Nyle kilns and they are also very happy with the units and support. I would definitely but another Nyle. Iíve had our 200 for ten years and run it all the time. This is the first real problem.

From contributor A:
The fan motor on my compressor would not start and pop the switch. The condenser was bad and I replaced it. The motor would still not start. So I put one of the blower motors in so I could run and put the old compressor motor up for a fan motor. It works fine up there.The switch seems to have a very low load requirement to kick off.