Pump Motor Not Running (humming Only)

[zenzic]

I have a 2HP AO Smith Centurion motor on my PacFab Challenger pump. I recently came back from vacation to find the pump not running. A mound of fireants had taken up residence in the motor which is an all-too-common occurrence with outdoor electrical systems in these parts. I first thought that the ants had burned out the motor, but further fiddling with it has me wondering.

When I turn the pump on, it hums, but will not turn. I took the motor off the pump and tried spinning it by hand with no problems. I hooked the power up and got the same hum, but got it to run just fine by giving it a spin. So that got me thinking start capacitor. I took the 30uF cap out and tested it with an analog ohmmeter (I don't have a cap tester) and it seemed ok. I replaced it anyway with a 30uF run capacitor (I _think_ it should work other than not fitting in the case), but it still did not work (hummed only).

What else can I do short of replacing the motor? Other than a bad start capacitor, what would cause this? Are there separate start windings on a single phase motor that might have burned out? Thanks in advance for any suggestions.

Jerry

[ps558]

I have a 2HP AO Smith Centurion motor on my PacFab Challenger pump. I recently came back from vacation to find the pump not running. A mound of fireants had taken up residence in the motor which is an all-too-common occurrence with outdoor electrical systems in these parts. I first thought that the ants had burned out the motor, but further fiddling with it has me wondering.

When I turn the pump on, it hums, but will not turn. I took the motor off the pump and tried spinning it by hand with no problems. I hooked the power up and got the same hum, but got it to run just fine by giving it a spin. So that got me thinking start capacitor. I took the 30uF cap out and tested it with an analog ohmmeter (I don't have a cap tester) and it seemed ok. I replaced it anyway with a 30uF run capacitor (I _think_ it should work other than not fitting in the case), but it still did not work (hummed only).

What else can I do short of replacing the motor? Other than a bad start capacitor, what would cause this? Are there separate start windings on a single phase motor that might have burned out? Thanks in advance for any suggestions.

Jerry

Hate to say it you need a new motor. If the cap didn't fix it the start winding is open or just shot. If you want a AO smith the replacement is a USQ1202 motor

[zenzic]

Hate to say it you need a new motor. If the cap didn't fix it the start winding is open or just shot. If you want a AO smith the replacement is a USQ1202 motor

Arg, I was afraid of that. I appreciate your help. I do have a couple of follow-up questions.

1) I had already looked around for a replacement pump to get an idea of the cost. The model you pointed to looks very much like my motor, but I had been looking at a model B855. The info on my motor says:

Part: 7-177897-22

Cat: B855

FR: Y56Y

I'm guessing that the different frame number 56Y vs 48Y is the only difference. Is the B855 the correct part? I really don't want to spend $250+ on the wrong motor.

2) While looking around, I saw the SVRS version of this motor, the BG855. While I'm not terribly concerned about suction hazards with the way my pool is plumbed, I do like the idea of having the motor cut off when the water level drops below the skimmer line or something like that. However, this version of the motor looks to be about $200 more. Has anyone had any experience with these motors that would lead them to recommend paying that much more?

Thanks,

Jerry

[quantumchromodynamics]

Another thing that can cause a motor to hum like that is a starter switch that is corroded and not making good contact. If you can clean the contacts, that might do it.

Look under "Electric Motors" on-line or in the Yellow Pages to find a motor shop in your area. For a small fee, they will give you an estimate on repair. Usually the estimation fee will count towards repair or replacement.

[Pool Clown]

Another thing that can cause a motor to hum like that is a starter switch that is corroded and not making good contact. If you can clean the fire ants out of the contacts, that might do it.

[stuartwall1]

Hi,

I have read your posting about the problem you had with your pump some time ago. I seem to have the same problem, did you manage to find a solution that could help me. I have changed the capacitor but have the same problem. Thank you for any help you can pass on to me.

Regards

Stuart