Home Improvement → Best stuff to use to help free up a dragging shaft fan?

So what info do you have on a B48 frame motor? I never had any luck.

Counter clockwise. The fan is a squirrel cage. Air is slung from the blades forcing the air outwards thus sucking new air from below.

So I went to the local grainger store and the guy cut the belt and started to measure and at first he was like it's a 4L belt but then he went back to saying it was a 3L and so he did not know the length so he ended up ordering to belts (they are out of stock)

He is stuck between a 3L470 or a 3L480 but should be here tomorrow by 8 am

Dumb question but seeing as the guy was unsure of the belt size I'm really paying for two belts or I guess one is to keep in stock? I ended up finding the 90 degree connection for the motor and I have 14 awg for it

Ended up going with the 3L70 belt when I picked up.

You need a "4L" or an equivalent "A" belt.

i can't believe how difficult this is,

go to pepboys or any place that sells belts and just match, i mean how hard is that?

i had a similar fan, entire belt minus 2 inches was left, took it pepboys 30 seconds later i walked out with a kevlar belt rated for 20 years, i don't understand why this was that big of a deal

You are a little late I tried 3 places, Auto Zone and Advance auto and a local lawn care place

you need to go to a place that stocks belts, pepboys if you have one stocks hundreds

car places generally don't stock them, not sure why pepboys does

napa might have them too

The way I understand the situation is he has the old belt, but we don't know if that belt was the right belt in the first place. Even if it was the right belt, it could be old and worn out making it impossible to measure to determine if it was a "4L", an "A" or a "3L" belt.

He insist it's a 3L belt, but looking at the sheaves on the equipment, I'm almost 100% sure it takes a "4L" or equivalent "A" belt. Then, looking at the new sheave and how the 3L belt fits in the new sheave, I am 100% sure it takes a "4L" or equivalent "A" belt. The belt should not bottom out in the sheave like the illustration on the right that I posted. His 3L belt is bottoming out. Not to mention, I've change hundreds of belts on belt drive centrifugal exhaust fans over the years, so I'm very familiar with them and their belt requirements.

i agree its the wrong belt, if the photo shows the new belt on the pulley

that said if he had the pulley in hand, all he needed was a piece of string to get the length

Oh Napa tried them too.. The closest pep boys is over 26 miles away

The pulley can use a few belts I put the belt on that the guy measured and its still too much slack with the 3L470 I ended up dropping down to a 44" belt I can move the motor closer but not away since it's at the max

I agree with Tex . That sheave is a a 4L or A/AX type sheave. When you ordered them, they should have specified what kind of belts to use.

I may be a bit of a prude, but I try to always use Browning sheaves and belts. More OEM fan manufacturers (Carnes, Cook, Trane, Carrier, etc etc) use Browning belt drives.

There is actually a formula you can use to figure out the belt length. I don't remember it off the top of my head, but you need the measurement between the shafts, and sheave diameters.

My opinion, I would use a Browning AX belt. AX34 (36") or AX 36 (38"). They might make an AX35, but Grainger doesn't list it.

When you get this all together, make sure you're not over-amping the motor. An RPM check of the fan wouldn't hurt either.

Can you post the link to that pulley so I can see for myself that it can use a few belts?