Does NEMA frame size matter ? 184 vs 213

[Indyducati]

Hello folks,

Shopping for a motor for a compressor project...

I've seen two motors with equal specifications,
other than the NEMA frame size.
Is there any benefit to the larger 213 frame
compared to the 184 ?

I've no space or fitment constraints.

Steve

 

[LMS]

They make adapters if that helps.

 

[marinusdees]

No. It doesn't.

 

[matt_i]

I think you will get larger bearings (check me here) in a larger frame size, as the case/housing is built for a larger horsepower lineup. Typically as you go up in size there is more "overhung load" on the shaft end for additional sheave grooves to drive bigger loads, and the bearings have to handle this. The case is going to be bigger and heavier also, just more mass.

In theory the bigger mass of a larger frame gives more thermal inertia to ride thru high load events (after all it has to deal with higher HP loads in the same frame size), but its really hard to kill a quality AC motor (if phase loss is active and fuses are sized right) if you ask me.

Unless planning an extreme duty cycle, I personally don't think its worthwhile, however if scrounging motors, or you can get something odd at a lower cost that will work, by all means its just fine.