My treadmill controller KXTL-230 is reading 330v DC across M+ and M- with motor disconnected. Is it normal or will it burn out the treadmill motor if I connect it to PCB? Kindly advice.

 

Is your mains supply 230?
If so, that is probably normal after rectification etc.
Not familiar with that model, but it is typical.
When PWM controlled it maintains the motor voltage, the voltage in and of itself does no harm when PWM controlled this way.

 

Hi Max, Thanks for your quick reply. Yes, my mains supply is 230v AC.
I connected the motor and switched on. Treadmill ran for a sec and then the 10A fuse blew out. Luckily motor survived.( I tested it with an external 12v 5A battery).
Can you suggest any possible reason for the blown fuse?

 

It could be in the Ramp up, whatever means they use for that unit, Look for the semi-conductors mounted to heatsinks.

 

Thanks Max. I think by semiconductors you mean the 3 pin MOSFET shaped components attached to heat sink. There are 2 nos, viz IRFP460C and F10U60DN. I replaced the IRFP460C with a new one. But I'm unable to get F10U60DN spare. Can you suggest an equivalent please?

 

Looks like the MUR1660CT is close, Newark have them.
Its a common cathode double diode, should be easy to test, out of circuit.

 

Thanks Max. I'll try 1660CT and let you know the result.

 

Hi Max,
Oofs. Finally able to get hold of MUR1660CT from Element14. (They are the outlet office in India for Newark, which is renamed here as Farnell, an Avnet company).

After replacing F10U60DN with MUR1660CT, its reading 0V DC across M+ and M-, whereas it reads 330v DC at pin2 (common cathode of 1660ct).

In the circuit board, pins 1 and 3 of 1660CT (anode ends) are shorted. Can you advise if its right? If it is, wouldn't the common cathode along with shorted anodes of 1660CT make it equivalent to a single diode?
Kindly advise. Tks.

 

Unfortunately I have not come across any schematic for that model, so it is rather a problem to trouble shoot from a distance!