Furnace motor humming 1

[fmehrtens]

I thought maybe someone would know this right off the bat.
Occasionally My furnace motor will not start and it will humm. Eventually it will start up after a few minutes. Is this the motor or the capacitor?? My reasoning tells me it's the motor, but maybe I could be in luck and try a new capacitor first.

Thank You

 

[DanDel]

You may also have a worn bearing in the motor or the pump and/or fan that is being driven.

 

[xnuke]

It hums because it forgot the lyrics.

(Sorry, I couldn't resist.)

xnuke

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[electricpete]

I have seen the exact same thing when my air conditioner fan capacitor died. Sometimes you can tell just by looking at the cap... if it's all bulged out, it's toast.

 

[electricpete]

 

[fmehrtens]

Thanks for the replys.. And the lyric thing was good. I just yanked it out for the specs, and went searching for a new one on the internet. The motor and capacitor come together and the cost is not bad. I'll go from a 1/3hp to a 1/2hp. The new motor I am buying is better quality so the amperage is almost the same. I will also have the squirrel cage balanced this time.

Thank you

 

[jbartos]

Suggestion: By buying the three-phase squirrel-cage motor the problem may still be there, and it may persists. Namely, if there is a power supply quality problem, e.g. the higher harmonic content in the power supply, the new motor will eventually start humming soon too. Normally, a good quality motor, either one should work fine for long time. Else, there would be the three-phase power distribution, and no single-phase three-wire power distribution.

 

[BONDIE]

CHECK THE CONTACTS IN THE HIGH/LOW LIMIT SWITCH...THEY COULD BE TOASTED , THUS SUPPLYING LOW VOLTAGE TO MOTOR.

 

[Laplacian]

We have an induced draft furnace fan that when shut down hot will sieze up if not rolled by hand. The shaft warps due to the 1500'C air and causes the 150HP fan motor to trip on overload. The motor shaft has to be broken lose manually before it will start successfully.

Were you talking about a cracking furnace or home heating furnace?

 

[jbartos]

Questions to electricpete (Electrical) Sep 22, 2003
Please, what is the picture below depicting? Where is the eng-tips beef?
<img src=

http://www.mclelland3850.freeserve.co.uk/assets/images/pics.h1.jpg

/></TD></TR><TR><TD ALIGN=&quot;Right&quot;>

 

[panelman]

i disagree that perfect toast needs a grill....our toaster works fine for two or 4 slices at a time

the Sesame Chicken Toasts looked good as well

 

[Mendit]

Many furnace motors have a start winding and a run winding, some times they will not start when the start winding switch does not function properly. This symptom is also accomanied by rotor bumping and banging as the motor starts.

 

[imok2]

Ck the supply voltage to the motor it should be within plus or minus 10% if ok it's probably the capicator

 

[jbartos]

Suggestion: It may be a good idea to pay attention to the harmonic content or power supply quality to the motor. My heater fan is terribly vibrating when plugged in one receptacle and running quietly when plugged into a different receptacle. I think that the phase to neutral voltage in the culprit receptacle is contaminated with harmonics or interharmonics.