Motor Replacement

Good Evening Coal Warriors,

I have a an EFM DF520 whose motor has been tripping the thermal cutout. Everything seems to turn freely so I decided to replace the motor. I'm sure it was original to the unit being installed in the early 90s if not early so it's time has probably come. I have the new motor from Grainger. What is the way of going about swapping it out. I know to put the dust shield on, the wiring is simple enough (I will keep an eye on rotation direction) but I'm not sure how to get the motor out. Any help would be appreciated. If I can I will change it out tonight for the wife since the unit was out when I got home from work. Thank you!! ~Jeremy

The first thing to un-do is the coupler, unless you have one of the early couplers that engage the ears on the fan. The later coupler has a set screw connecting it to the gear box and another connecting it to the motor shaft.

After the coupler is disconnected, you can remove the three bolts holding the dust shield on and pull the motor, dust shield and fan. Fan has a set screw, dust shield has 2 screws holding it onto the motor. Install the fan and dust shield on the new motor and put it all back together.

Here is a video of just how the rotation of the motor can go wrong.



Good luck,

-Don

Don,

Thanks for the quick replay!! I did get the rest figured out and had the motor swapped out. Of course I lost the 50/50 and my motor was going the wrong way! Your video made it very easy to tell that the gear box was headed CW so thank you for sharing that!! Hopefully this gets me back in shape and ready for when it gets really cold! It's stoking now and coming back up to temp.

Does anyone know if the motor comes oiled or I should do that right away? I got it from Grainger and it looks like it is a Century.

I would give it a drop of oil.

I agree, if it has an oil port, put a drop in it.

Glad you got the direction of rotation figured out. I had read about that being a problem on EFM's, I never even gave it a thought when I was changing my motor. It took me about 15 minutes to change the motor on a Sunday morning. I turned the switch back on and went about my business. A few hours later I came back to a very small fire!

I didn't realize the thing would just keep stoking with the motor running back wards, but it does. That's why I thought the video was necessary. I'm glad it was helpful.

-Don

Ok, follow up question. I seem to have had a pretty $hitty burn the last couple of days when it should be stoking along nice with all the cold and wind that came in. So, considering that's what changed I double checked my motor. Yes, the gearbox is turning CCW but in order to do that the motor is also spinning CW when looking at the shaft end and CCW when looking from the rear end. That would mean it's not blowing very well into the unit correct? Could it be possible my gearbox is supposed to turn CW?

Thanks for any help. I always seem to come up with a mystery...

If looking at the motor from the gearbox side, it should spin CCW. sounds like yours is turning backwards.

Yea it's definitely turning CW from that end sounds like after dinner I need to reverse it. Is there any negative to the gearbox then turning the CW direction? I know in the video you said the gearbox turning CW was not good for it.

The gearbox will be fine, just get locate the reverse switch for the motor and you should be all set.

Like Rob said, the gearbox will be fine. If you let it run like that for months it might ware the gears the wrong way but a few hours won't hurt it.

Funny how these stokers will keep stoking with the motor going the wrong way!

-Don

Does anyone have links to purchase a replacement motor? I did a search and couldn't find any after about 10 minutes of searching...

I have an AO Smith on my EFM DF520 now. I googled the numbers on it, but nothing came up. It seems to be the same replacement motor I used on my A/C compressor or at least the specs match - 1/8HP, Type S, 1725RPM, 115V 2.5A, 1 PH, 60Hz, 1.0 SF, F48N FR, Thermally Protected Type M

Thanks,

Dave

Thanks Rob. That is good price too.