Pull them and buy them based on the dimensions. (if it really has brushes)
Pull them and buy them based on the dimensions. (if it really has brushes)
Why wouldn’t it have brushes?
My grandfather used to repair electric motors and grainger can still support a lot of obsolete old stuff. If you can’t find what you need anywhere else Grainger can probably get it.
I forget where you live but there’s probably an 80+ year old man somewhere around you with the tools to dress the armature before you stick new brushes on it. I can’t remember what it’s called but there is a tool that looks like an eraser made out of what looks like ceramic for dressing the armature where the brushes rode on it the last 50 years.
edit: commutator dressing stone. Amazon has them for $12 bucks
....
I can't believe it has brushes, strange. It isn't starting contacts you're seeing sparking is it?
Those are definitely brushes, I learned something today!!!11one.
1750rpm AC motor meant induction motor to me. I'm really curious why it was done that way, should be able to run on DC. Does the RPM change with compressor pressure?
Post pics of the brush out of the holder and use a caliper and measure them ~ I'll ask my ex boss he knows everything about AC & DC motors.
Nice, it probably will last another 50. Are the bearings oil-able? Or greaseable? Not much to go wrong with it.
I’ve got a 20 hp 3 phase motor at work that wiped itself out. Not that old but has greaseable bearings that I think someone pumped grease in that didn’t mix with the previous grease. It’s ran by a VFD and the VFD faults for overload when I try to turn it on.
Nice, it probably will last another 50. Are the bearings oil-able? Or greaseable? Not much to go wrong with it.
I’ve got a 20 hp 3 phase motor at work that wiped itself out. Not that old but has greaseable bearings that I think someone pumped grease in that didn’t mix with the previous grease. It’s ran by a VFD and the VFD faults for overload when I try to turn it on.
Post pics of the brush out of the holder and use a caliper and measure them ~ I'll ask my ex boss he knows everything about AC & DC motors.
Also, less or no grease is better than too much grease.
According to motor people (like Siemens), electric motor grease is very, very specific grease, and if combined with other greases it will either turn to oil, or (more likely) harden and solidify. I have been told multiple times how important it is to use only the correct stuff, in the correct amount, at the correct hours.
Also, less or no grease is better than too much grease. I believe this part because we've got motors (150 hp) that almost never shut off, and have lasted 10+years. Lots of them.
I have no idea why, and it seems stupid to need such special stuff.
They are oil-able. I removed the little plug and squirted in a few drops of Mobil 1 after I reassembled it. I am going to change the oil in the compressor side this week, too.
That should do it, any light viscosity oil should be fine. Did you dress that commutator or just put it back to work? Might be the picture but it looks like it was in pretty ugly shape which happens when the brushes reach the end of their life. The sparking you saw burns the outside but a few turns with even some emery cloth can make them look new again.