Alternate title: How can there be so many damn motors?
Having taken the blower motor in my furnace apart to lubricate it, I know that the repair is temporary and I'm going to need a new motor soon. When I had it out, I tried to write down all the numbers on the motor tag, but the main part number doesn't seem to be matching up to anything that gets immediate hits on google. Maybe I didn't read it right. The searches that I have done so far have led me to realize that I'd have better luck searching by the furnace model number! Here's what I've found out so far:
From the motor:
Westinghouse S# 321PA45
HP 1/3 RPM 1050/900/800
V120 FR FU48 INSb CL.A
A7.4
Cap 7.5 MFD/370V
E46993
(the A seems to be a numeric digit in all other westinghouse motor part numbers I've found so far, but I have no idea why I thought that this was an A on the tag)
(1/3 is not a very common HP. It seems to be a 3-speed motor)
(Seems to be a 120V motor. FR FU48 is frame size 48. I've seen FR DU48 sometimes)
(The attached cap was a 7.5 uF. This appears to be what's called a "Run Capacitor")
Links from my search:
This page had a westinghouse motor, but a completely different one:
http://stores.johnstonesupply.com/155/tabid/1783/default.aspx?product_group=5723
This is a guy searching for a completely different Westinghouse motor. The answer recommends a Fasco replacement motor, and explains to get the run capacitor appropriate to the replacement motor.
http://www.justanswer.com/appliance/4asur-bad-westinghouse-blower-motor-info.html
MOT1036A from this place is a 4-speed but seems pretty similar to mine. I might be able to use a general purpose replacement if I found one with the same frame size (and shaft diameter, which of course I neglected to measure)
http://www.americanhvacparts.com/Merchant2/merchant.mvc
Update: Wow, they sell the complete blower assembly!
http://www.americanhvacparts.com/Merchant2/merchant.mvc?Session_ID=fc56c04bf8edf0dd4fec53724a54df59&Store_Code=AM&Screen=PROD&Category_Code=m-york&Product_Code=MOT6901A
Here's a close Fasco motor, 1/2 instead of 1/3 HP. No specs so I don't even know if it is even the same frame size, but it sure does look similar:
http://www.americanhvacparts.com/Merchant2/merchant.mvc?Session_ID=fc56c04bf8edf0dd4fec53724a54df59&Store_Code=AM&Screen=PROD&Category_Code=m-york&Product_Code=MOT2700D
Here's a 1/3 HP 3-speed frame size 48 motor. I'm not sure why I keep getting hits on 1075 rpm motors when Mine's a 1050 rpm.
http://www.hvacpartsoutlet.com/1/3-hp-115v-3-speed-1075-rpm-blower-motor.aspx
Here's a guy looking for a really similar motor. He was advised to hit the Grainger catalog to find a cross reference. I tried it and was rewarded, finally, with an easy-to-browse website design, but didn't find any specific cross reference info to Westinghouse.
http://www.practicalmachinist.com/vb/general-archive/old-elect-motor-frame-conversion-new-95444/
Here's a close hit on Grainger:
http://www.grainger.com/Grainger/AO-SMITH-Direct-Drive-Blower-Motor-4KA34?Pid=search
