Pump noise

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H

habajaba

0
LifeTime Supporter
Jun 11, 2007
27
Bradenton, FL
So the pool pump on our new house is making this weird sound. I'm familiar with the bearing squeal, but this is more of a glug glug glug. Kinda like if my pump had a racing cam in it ;-). The previous owner said it was due to it being 2hp and having to pump to the roof for the solar heat. I didn't fully buy that, so I asked the pool company that installed it to come out. The pool company says it's a bad capacitor on the motor and want to replace the motor for $300. I thought I'd try and get my friends at TFP to lend me a hand in figuring out exactly what's wrong. I'm thinking a capacitor would be an easy fix and certainly less than $300. But don't want to go through the hassle if that's not a proper diagnosis. The pump works fine, but the constant noise is annoying. And once someone builds a house next door, they will have our heads if we leave it like this. I can hear it indoors on the 2nd floor with everything closed.

I put a video of it up at http://www.youtube.com/watch?v=E3oGv7Qk4cY.

Thanks in advance!
 
Really? $300 to replace a cap?
If you can get the details off the motor nameplate, the capacitor will be easy. Most likely, you can read the cap specs off the cap directly.
I am wondering if it could just be pump starvation though.
 
Ohm_Boy said:
Really? $300 to replace a cap?
If you can get the details off the motor nameplate, the capacitor will be easy. Most likely, you can read the cap specs off the cap directly.
I am wondering if it could just be pump starvation though.
Click to expand...


If you do decide to replace the capacitor, be careful. Remember, a capacitor's function is to store energy so it can have high voltage on the terminals even if the power is off. Large capacitors are typically stored with the terminals connected because they can soak to dangerous voltages even when not connected to a power source.
 
Ohm_Boy said:
Really? $300 to replace a cap?
If you can get the details off the motor nameplate, the capacitor will be easy. Most likely, you can read the cap specs off the cap directly.
I am wondering if it could just be pump starvation though.
Click to expand...

They said they don't do motor repair and it's $300 for a new motor. But then she mentioned that it was the cap. I have worked with caps in car stereos and understand some basic electrical stuff. So I figured it might be worth a shot to repair. I'm not sure where the cap is located and figured I shouldn't go taking anything apart until I had the part in hand. I attached a photo of the motor specs.

How could I test for starvation? Partially close the outlet valves to slow the flow?

I kinda figured there shouldn't be anything wrong with the setup, as it's a 3 year old house and everything was installed professionally. But, anything is possible, right?
 

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svenpup said:
If you do decide to replace the capacitor, be careful. Remember, a capacitor's function is to store energy so it can have high voltage on the terminals even if the power is off. Large capacitors are typically stored with the terminals connected because they can soak to dangerous voltages even when not connected to a power source.
Click to expand...

Thanks, you're right. That's a great disclaimer. Capacitors can be very dangerous and not something that inexperienced folks should play with.
 
That noise almost sounds mechanical to me, as opposed to an electrical issue, but the capacitor should be pretty easy to rule out. I expected to see a run cap value on the motor nameplate, but alas, no. No matter. For one thing, there will be a part number, or a mfd and voltage rating on the cap itself. If there is no legible info on the cap, AO Smith should be able to provide the proper value based upon the motor info. Failing that, you can try around a 30uF 370volt run cap as a test.

Technically, in an operating circuit, a run capacitor shouldn't be able to store any charge. It should all dissipate virtually immediately after shutoff, so there should be little shock hazard involved once the power is shut off/locked out.

Have you tried to spin the motor by hand with the power off to see if there is any obstruction?
 

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Ohm_Boy is correct. Most larger motors have a start cap and or a run cap. The start cap will engage/fire until the start switch is open. Then if a run cap is used it will then engaged. Most of the time a run cap has a very low MFD rating and its used just to take some of the load off of the motor to make it more efficient. In a lot of cases you could have a run cap fail and you wouldn't really notice except if you were checking the amp/watt draw or noticed your electric bill increase slightly.

Now if the start switch is trying to engage and disengage while it was running, it would cause the motor to run on it's start windings and run windings which could make it speed up and slow down or sound like it is under a heavy load on and off. Normally the motor wouldn't last to long if that was the case. Either it would trip the overload or you would smell something overheating. Hope that makes sense.

Tim
 
Ew, ew, ew...I can help! :-D I really wish I didn't have this much knowledge on this, but alas....that hump on your motor has the capacitor in it. Turn off the power (I know...DUH!), unscrew the plate covering and unplug the capacitor. It has a label with all needed info. I took this info and ordered another off the internet. It was around $35. A lot less expensive that replacing the pump! That way, if it's not the capacitor you're not out of a whole lot of money! Another problem with noises I have had in the past is due to the impeller being full of (pine needles in my instance) debris. Have you opened up the pump and checked the impeller??

Well, just my 2 cents....I'm going back to lurking now! :lol:
 
Sorry I'm so late to this thread.

I finally watched the video and that sounds like a mechanical thump. Have you taken the wet end apart to see if there's something in the impeller as midtngal suggested? That's where I'd start.
 
Wow. Thanks everyone! Looks like I'm going to learn how to take apart the pump. Then, I'll check the cap next. Not only have I never done this, but I'm still completely unfamiliar with this specific pool and equipment. Everything at the old place was Hayward. Guess there's no better way to learn, eh? Wish the past owner had left me the manuals like I did with my old house. Oh well, off to the Pentair website! I'll report back with my findings.
 
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