troubleshooting a VS motor

[John Frankl]

Hello,

I'm hoping some of the more mechanically-inclined folks here can help me. On my disc grinder, I have a Leeson 1/2 HP VS DC motor hooked up to a Leeson Speedmaster contoller. Hooked up to that I have a foot switch. It has been great--until tonight. I was flattening some guard stock when the motor started to jog a bit. It jogged very slightly about three times, then just quit!

Now when I step on the foot switch, the light goes on on the controller, but the motor does not respond. When I disconnected the foot switch and tried the motor manually, same result. So electricity and a signal are getting to the controller, but not to the motor. Could this be something simple like a fuse?

Any and all help will be greatly appreciated,

John

 

[rfrink]

John,

A few thoughts about your set-up.

The foot pedal is a great idea! There are 2 methods to do it...one good and one is "not so good".

Are you using the footpedal to control the line voltage into the controller? That is to say, is the foot pedal turning the controller input power on and off? This is the "not so good way" to do it.

The controller actually has an Inhibit circuit that is designed for frequent starting and stopping of the motor. Your controller would be powered all the time and the foot pedal would provide and internal signal to the controller which starts and stops the motor. The inhibit pins are located on the PCB just above the accel pot. When you close the connection between the pins, the motor stops, when the connection between the pins is open(normally) the motor runs. I'm sure that your foot pedal has normally open and normally closed options which will work fine. This reduces the inrush of electrical power to the controller everytime you step on the pedal because the controller is contantly powered. The inhibit circuit also allows the controller's accel and de-accel/braking functions to work. If you simply shut off the electrical power to the controller, then all of it's functions shut off as well.

To answer you question about why it doesn't run,...
There are fuses inside the controller. Also, check the connections incase something came loose.

The SpeedMaster series has 9 different controllers....what is your model number?

Confusing?? helpful??...

-Rob