-
Condenser Fan Motor Over Heating
Had a call today bad condenser fan motor.
Old Motor was AO Smith 1/3 1075 rated for 1.6A
Replaced with a Diversitech multi tap motor - wired for 1/3 hp.
About 3 hours later get a call unit not cooling, return to find the motor is overheating and cutting off
Waited for motor to cool down and restarted unit, amp draw was 2.8-3A. Motor Name Plate Rated amps is 2.8
Checked voltage going to motor - 238V.
Coil is clean, fan blade in proper position, proper rotation, and moving adequate air.
I have used the Diversitech motors for some time and never had any issues, but I am stumped.
Whats killing the motor?
-
-
Was is the make/model of condenser?
-
What was the amp. draw when you first replaced the motor with all panels on? If it was 2.8 and it's rated for 2.8/3 that alone should have gave you pause. Maybe the motor got damaged. Even thou they are protected in a box seen where they fell on the shaft. New correct size capacitor. All your high voltage terminals tight. Does the motor hook directly to the contactor or somewhere else first. Is old motor an open motor, is the new one a closed motor. OEM fan blade
-
-
Ok just got to throw this out there, did the old blade pitch look like the pitch of a 1075?
Sent from my iPhone using Tapatalk
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
-
Not sure why the pic turned sideways
-
Tag shows 1.3amp motor originally. Maybe that motor you changed was wrong also. My first thing would be capacitor and make sure it measures correctly. Then like Mr Bill said, the fan blade. Maybe the original motor was 825 rpm. I think lennox is that way.
Sent from my SM-G900V using Tapatalk
-
Post Likes - 1 Likes, 0 Dislikes
-
Originally Posted by
Bazooka Joey
What was the amp. draw when you first replaced the motor with all panels on? If it was 2.8 and it's rated for 2.8/3 that alone should have gave you pause. Maybe the motor got damaged. Even thou they are protected in a box seen where they fell on the shaft. New correct size capacitor. All your high voltage terminals tight. Does the motor hook directly to the contactor or somewhere else first. Is old motor an open motor, is the new one a closed motor. OEM fan blade
Didn't check amps on new motor. Until I returned the second time. Checked all connections and they where secured tightly. Thought ok maybe bad motor out of the box. Replaced motor. After about 10 minutes it started heating up as well. Motor is wired through control board relay on one leg and the other leg is wired to contactor. Moved leg from control board directly to contactor same results. New capacitor was installed with first motor. Both motors are closed type. Amp draw can only be checked with service door open. Best I can tell it is OEM blade.
-
Originally Posted by
icy783
Tag shows 1.3amp motor originally. Maybe that motor you changed was wrong also. My first thing would be capacitor and make sure it measures correctly. Then like Mr Bill said, the fan blade. Maybe the original motor was 825 rpm. I think lennox is that way.
Sent from my SM-G900V using Tapatalk
See photo in post #4 of old motor. 1/3 1075. And yes new capacitor installed but double checked on second trip and it was spot on. I have serviced this unit for at least the last 5 years and the blade has never been changed. Not saying it is not the wrong blade, but I know it has been working. I guess I need to see if I can cross reference the current blade with the OEM blade.
-
Condenser Fan Motor Over Heating
What's weird is the motor that was in there says 1.6 amps and the tag on the unit says 1.3 on the motor.
Sent from my iPhone using Tapatalk
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
-
Post Likes - 1 Likes, 0 Dislikes
-
Originally Posted by
DeputyDawg605
Had a call today bad condenser fan motor.
Old Motor was AO Smith 1/3 1075 rated for 1.6A
Replaced with a Diversitech multi tap motor - wired for 1/3 hp.
About 3 hours later get a call unit not cooling, return to find the motor is overheating and cutting off
Waited for motor to cool down and restarted unit, amp draw was 2.8-3A. Motor Name Plate Rated amps is 2.8
Checked voltage going to motor - 238V.
Coil is clean, fan blade in proper position, proper rotation, and moving adequate air.
I have used the Diversitech motors for some time and never had any issues, but I am stumped.
Whats killing the motor?
The original was probably a 1/6 or 1/5 HP, and the 1/3 that you used is oversized and overheating.
-
Post Likes - 1 Likes, 0 Dislikes
-
Originally Posted by
Mr Bill
What's weird is the motor that was in there says 1.6 amps and the tag on the unit says 1.3 on the motor.
Sent from my iPhone using Tapatalk
Yes Mr Bill I seen that also. Leaves open the posibility that the person servicing the unit prior to our company may have changed it out. Just puzzling why it has worked for the last 5 years or so.
-
Originally Posted by
hvacrmedic
The original was probably a 1/6 or 1/5 HP, and the 1/3 that you used is oversized and overheating.
Name plate on unit calls for 1/3 hp. See photo in post #4
-
Originally Posted by
DeputyDawg605
Name plate on unit calls for 1/3 hp. See photo in post #4
Ok, well I've been through this with a Lennox unit before. Order the oem motor and save yourself some trouble.
-
Don't you have a straight one tap good new/used 1/3 HP motor reversible rotation kicking around ( like the one you changed out ) instead of the multi tap wired for 1/3HP motor to try
-
Originally Posted by
hvacrmedic
The original was probably a 1/6 or 1/5 HP, and the 1/3 that you used is oversized and overheating.
Warning!!!!!!!! Hypothetical situation!!!!! You say (hvacmedic) that IF an original motor had been 1/6 hp but a 1/3 was now installed, that it may over heat. Would that be because of possibly not enough airflow over the motor now?
Sent from my SM-G900V using Tapatalk
-
Tag says 1/3 hp I just don't think it likes that multi tap motor.
Sent from my iPhone using Tapatalk
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
-
Was blade height on the universal motor the same as with the original motor? If blade height is not correct it can overamp the motor. Seen more than a few times where original motor was shorter than a universal causing blade to be to low. Had to order factory replacements for these.
Sent from my SM-G900P using Tapatalk
-
Post Likes - 2 Likes, 0 Dislikes
-
My guess is that the motor he pulled was the original, I think Lennox/Concord uses the AO Smith.
Sent from my iPhone using Tapatalk
__________________________________________________ _______________________
Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
-
Post Likes - 1 Likes, 0 Dislikes
-
Originally Posted by
Cimerian
Was blade height on the universal motor the same as with the original motor? If blade height is not correct it can overamp the motor. Seen more than a few times where original motor was shorter than a universal causing blade to be to low. Had to order factory replacements for these.
Sent from my SM-G900P using Tapatalk
I second this. The multitap is bigger. You can see on the picture the blade was right next to the old motor. My guess is the blade position is the issue. I know you can't do it on a concord but for the next time take a look at these pictures to help in these situations.
-
Post Likes - 1 Likes, 0 Dislikes
Reply
Professional Member*
hedrash liked this post.
