Reasonable Fan Motor Temp

[jeepinerdeep]

I have this Air King fan in my shop. https://www.airkinglimited.com/wp-content/uploads/2020/09/9025Spec1.pdf

About 5 years/25,000 hrs on it.

New bearings ( old one near the blade was noisy ) and new motion bushings ( worn slap out ), so it's clean and in good repair as of today.

What do you guys figure a reasonable motor temp is right above the winding? I'm seeing 160F right over where the winding lives, settled out on continuous run. Ambient 65F.

I know that's reasonable on a real industrial motor, but this thing is no baldor.

 

[nadogail]

I think 80 degrees Celsius is about the maximum allowable temperature rise. When you put your hand on the motor you can get an approximate determination of the temperature.

 

[wyliesdiesels]

I think 80 degrees Celsius is about the maximum allowable temperature rise. When you put your hand on the motor you can get an approximate determination of the temperature.

Based on?

 

[mike93lx]

If it has been running for 25k hrs at those Temps, I would say it's fine.

Or is or recently running hotter?

 

[jeepinerdeep]

If it has been running for 25k hrs at those Temps, I would say it's fine.

Or is or recently running hotter?

That's exactly what I'm not sure about and its in my head now. I don't know how I feel about leaving it unattended now.

 

[mike93lx]

That's exactly what I'm not sure about and its in my head now. I don't know how I feel about leaving it unattended now.

If you don't trust it, replace it.

I don't think I would worry about it, but that won't make you feel better

 

[TRWham]

NEMA says 60 C rise or 105 C (221 F) max for insulation class A and that's the lowest class.

 

[jeepinerdeep]

If you don't trust it, replace it.

I don't think I would worry about it, but that won't make you feel better

I think it's probably fine too. I think I'll let it run for a 12 hr day when I'm in the shop and monitor for sanity. A new one is $350....yikes.

NEMA says 60 C rise or 105 C (221 F) max for insulation class A and that's the lowest class.

I'm well within that, and I do know it has a thermal cutout that has never tripped, I probably just got in my own head.

 

[nadogail]

Based on your experience feeling other well installed and properly operating motors.

 

[Lightning rod]

The insulation class determines the MAX temp rise over ambient

B - 80 degC avg rise over 40 degC ambient = 120 degC total
F - 100 ....................................................................= 140
H - 125 .................................................................... = 165

These are maximums allowed. Most manufacturers get close to these temps to reduce costs

Depending on what you are using to measure temps, you might be measuring air temp , not winding temp

In any event, your temps look very low
The fact that there is a lot of air running over the motor probably has a lot to do with it

 

[fitter30]

Totaly enclosed pfc motor 40°c - 104°f plus ambient. Should able to look at motor specs.

 

[Innovate1]

The insulation class determines the MAX temp rise over ambient

B - 80 degC avg rise over 40 degC ambient = 120 degC total
F - 100 ....................................................................= 140
H - 125 .................................................................... = 165

These are maximums allowed. Most manufacturers get close to these temps to reduce costs

I knew a very smart engineer who used to joke "If it's not on the verge of burning up it's over designed." Which is basically what you are saying. Seriously, it sounds ok to me. They are designed to run hot and it sounds like you are below design limits. It the current draw is within the nameplate rating, it's performing ok, and the vents aren't blocked with crud then I don't see an issue.

Totaly enclosed pfc motor 40°c - 104°f plus ambient. Should able to look at motor specs.

I think you mean PSC motor...

 

[pancho400cid]

I knew a very smart engineer who used to joke "If it's not on the verge of burning up it's over designed."

Nice!

 

[jeepinerdeep]

Closure. Got another 40 hrs out of her and a bright blue light cometh. No more worky. Luckily I was standing there when it happened.It's in the scrap and has been replaced.

 

[mike93lx]

Closure. Got another 40 hrs out of her and a bright blue light cometh. No more worky. Luckily I was standing there when it happened.It's in the scrap and has been replaced.

And the magic smoke hath been released. She had a good run. Pour one out in memoriam

 

[nadogail]

When the Magic Smoke, that was put in at the factory, escapes the item is officially terminal.