Furnace!

2100 last night. Out in the shop...wife calls....something's on fire and a hang up.


Furnace. Gas. Payne. High efficiency and all that rot.

Popped the covers, motor...can't hold my hand on it for long.

Killed power locally, borrowed space heaters from neighbors.

2230, had a think, back down to the basement furnace room.
Power up locally, hold the interlock in, and wait. All the other stuff cycles...hear the main relay close, and no motor.

Reach around the open and of the squirrel cage and spin it. Spools, flame propagates, heat comes out.

Called an electrician neighbor this morning...he had a cap in his truck....got it, stuck it in, been cycling normally for over an hour...and I did the back of hand test on the motor...less than ambient.

Saved $165 service call and $50 for a cap........or whatever they'd nail me for the cap.

I had that happen to me a couple months ago (while still running the A/C) - unfortunately wasn't just the cap, the whole motor had gotten stuck. Was able to spin it and it ran for about an hour before it froze again, was cheaper to get a replacement than to get it rebuilt.

True. Seen that, motor gets hot and seizes up.Generally, spin it, half a turn to a turn if it's going bad.

This one, geez, 50 turns with one spin before it finally creeps to a stop? So far, cycling and working fine, no heat on the end of the motor like last night!

TOC said:

True. Seen that, motor gets hot and seizes up.Generally, spin it, half a turn to a turn if it's going bad.

This one, geez, 50 turns with one spin before it finally creeps to a stop? So far, cycling and working fine, no heat on the end of the motor like last night!

Click to expand...

Even brand new I don't get that many rotations on momentum alone. Sounds like you probably have a really well built ball-bearing motor instead of the cheaper bushing bearings.

My thoughts, too. Payne high efficiency....PVC inlet and exhaust. Figure they didn't scrimp on bearings.

Daughter, S-I-L and grandkids furnace quit couple of years ago. The motor as usual horizontal, the sleeve bearings, due to weight of the armature and fan most likely, wore on the downside so much the armature was dragging on the field. Actually same source of my starting cap got me a motor for that one.

Down here the motors are running A/C units, nearly all year 'round. Over the thirty-plus years we've been in the hovel, I've replaced caps in mine and neighbors' units, mostly the outdoor compressor/condensor side. Most common cause of cap failure in those has been ANTS! For whatever reason they seem to be attracted to the capacitors, build a mound around them and short the things out. Second most common is the fan motor in the outside unit. Vertical axis mounted motors seem to wear the lower bearing to near seizure, then the smoke charge leaves the motor.