Dc variable speed motor

[ptemko]

Dc variable speed motor. I am trying to find a site that sells the testers for these motors. So far I have changed out 3 in the last year not known if it was the end bell or the motor. The company wants us to change the whole assembly more money that way. I would like to be able to test them properly. I just had one of the other tech's on call phone me not knowing weather it was the board or the dc motor. I got him to check the smaller connector for power first before getting the board and motor. He phoned me back saying it was the motor because he had power to the motor. This was his first dc motor he has run into with problems.
We are installing more and more furnaces with these motors and I think it is time to get the proper tools to do the job. I will be talking to the service manger on Monday about getting these testers for us. Point me in the right direction for some testers for these motors.
Thanks Peter

[amickracing]

Trane and A/S have testers for them. I'm pretty sure Zebra has some that work good too. (http://www.zebrainstruments.com/)

I don't have one yet...

My hillbilly testing method. If I find a bad one, I yank the module off the motor and look for brown spots (common failure in these).

To test the motor (that hardly ever goes bad) I jumper 2 of the 3 connectors. Doing this should make turning the shaft mighty hard (compared to unjumper'd). If it spins easily with the jumper in place, then the motor is bad. You can also ohm the 3 legs out. They should be very very close, I can't recall what you "should" expect, but on the one I found that was bad, that one leg was way off what the other 2 where.

One other fun experiment. If the motor is bad, pull it apart. There has been a common issue of 2 windings being shorted together (thanks Payson for showing us the light). You "could" pop them apart, paint something on there to insulate them again and it'd likely work fine... but I'd replace it just incase (and save the motor for your garage inventions).

[OregonYeti]

In our company we replace the whole thing because there may have been non-fatal damage aside from the cause of failure, and warranty issues (our cost of a callback). At least that's what "they" say. Of course it does make us more money too.

[ptemko]

I changed out my last for $1779 only 2 months out of warrenty. The customer just about had a heart attack.:eek: I just charge what I am told.
But that is just wicked. So how much did he save in hydro after the cost of replacement. Also what happens if it ever goes again. That would be a very unhappy customer.

[ptemko]

I still have that motor sitting in the back of the truck. I just can't bring myself to toss it in the dumpster at work. I have to get a tester to check these motors out. Save the good part for a rainey day for something.

[a\c don]

The GE Tekmate tester is available from most supply houses, around here Totaline, Gemaire, Baker Bros., Johnstone, Pioneer Metals all sell them.
Should be about $45.00.

[mark beiser]

Other than the old ICM1 motors, the only time I have changed the entire motor and module assembly was one where the bearings had failed in the motor, and a few times because the 2nd rate distributor for the brand of equipment didn't stock just the modules.
I haven't run into one yet where there was a problem with the motor windings, but I check them every time.

The motors are to durable and to expensive to replace just because the module failed.


I got him to check the smaller connector for power first before getting the board and motor. He phoned me back saying it was the motor because he had power to the motor.

The motor module has line voltage power to it through that connector 100% of the time. Most brands also have control voltage going to the module all the time.
You need to know exactly what each pin is for to test them with a DMM, or you need one of the several testers that are available.
I'm currently using a Variable Speed Zebra. I like it because it lets me observe exactly what the motor is being told to do, what the motor is doing, lets me control the motor directly, and has a test mode for the motor windings that is a bit more advanced than what you can do just ohming out the motor.
http://www.zebrainstruments.com/VarSpeedZebra/VarSpeedZebra.htm

[davidr]

www.thedealertoolbox.com

Lots of good info on this site.

[hvaceric]

I use a 9V battery with some leads on standard 9V connector, I don't know about other Mfr's but Lennox gives the pinout to make a tester. I wonder if all the motors use the same pinout.

[refrigerationtech]

I use a 9V battery with some leads on standard 9V connector, I don't know about other Mfr's but Lennox gives the pinout to make a tester. I wonder if all the motors use the same pinout.

be nice to post that pinout to make a testor?

[hvaceric]

Been busy and now my truck is in the shop, I'll get my truck with the diagram back later this week and see about posting it.

[weber]

I also use the techmate from GE, works geat and less the 50$.

You can get this for most supply houses or from GE's website.