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Hi,
This old dryer has been used daily since 2005 and owes me nothing. But a new dryer is £500 so I’d like to fix it. But I’ve run out of ideas.
The symptom: When the start button is pressed, there is a slight bump from the motor, but nothing else happens.There is no humming.
Diagnostics so far:
- The 8uF capacitor had failed (reads 1.7uF). I replaced it, but the problem remains the same
- Sensors all seem fine
- two Elth brand bimetalic thermostats in the heater are both showing continuity
- temperature sensor in the drum has low resistance which changes in response to warmth
- drum sensor brush has good connectivity
- Switches seem fine
- Door switch working
- Power button working
- Program selector seems to work – e.g. it resets the system OK
- Connectors all in good condition and firmly plugged.
- Control board has no obviously damaged components (capacitors are fine)
The elephant in the room, of course, is the motor, which I struggle to understand. It is a single phase AC motor which seems to be used across a wide range of dryers, type CK-302300-21R01. I have gathered the following information:- Resistances
- R 1:3 = 28 Ohm
- R 2:3 = 29 Ohm
- R 1:2 = 56 Ohm
- Behaviour
- All the above go open circuit when the motor turns. Centrifugal switch?
- On start, there is a small jerk of the motor, but only enough torque to twitch the drum before it stops
- I tried turning the drum while pressing start. I have done this many times and it does nothing apart from once, when the drum started spinning, the heater came on and it appeared to be functioning normally. To prevent the heater blowing, I powered off immediately. I have not been able to reproduce this.
What next? Motors are >£100 so not something I’d take a punt on. I’m confused by the motor – why do ALL the resistances go open circuit when it turns?
I’m pretty stumped! What can I try next? I have a simple digital multimeter, which includes capacitance and current clamp, but nothing else.
Many thanks,
JK
No ideas? I could use some tips on further diagnostics. I want to check if there is power going to the motor circuit, I know there is momentarily, but not after that. Something must be telling the controller to stop supplying volts?
the motor is fairly simple but as with all motors it has a protection stat in the windings. it sounds like the stat goes open circuit and soon as its energised. if you leave it to cool down then it does it again.
As an engineer would test for power both live and neutral at the motorDave
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