Pool Motor hums but won't start - please help!

bzbee

Active member
Aug 30, 2019
26
North TX
Hi All,

I am new here, and this is my first post. Last month we bought a house with a small pool (about 15,000 gallons by my estimate). The pool has a Hayward SP3015X20AZ Super II Inground Pool Pump driven by a US Motors EB130 2HP Motor. I thought motor ran loud & rough, but the pool guy said it was normal (and both my neighbors motors also sounded similar). I've been mainitaining the pool myself with the advice & tips here at TFP (Thank you!), and the pool looks real nice, clean & blue.

The motor is set to run from 10AM to 6PM everyday. Last week, I was home during the day and noticed that the motor was randomly stopping abruptly and restarting after a few minutes. I thought it was over heating because it was very hot here in Dallas. It ran ok during the weekend so I didn't look into it further.

Well, on Monday it stopped working for good. I hear a humming noise from the motor but it won't turn. I did my research and here is what I have tried so far:

a) Checked the voltage at the motor with a multimeter - getting steady 220V.
b) Checked the pumps impeller for any debris - none found and it turns freely.
c) Checked the motor shaft at the back and it could be turned freely with my fingers.
d) The motor has only one capacitor (35MFD, 370VAC) and it looked ok. I pulled it anyway and tested it with a multimeter which read less than 1MFD. So I assumed the capacitor was the problem and got a replacement from Amazon with the same specs. Tested it and it reads 35.5 MFD on my multimeter. So installed it and thought the problem was solved. Nope, motor still won't start, only hums.
e) With the power on, rapped on the motor casing with a rubber mallet, tapped lightly on the motor shaft - nothing happened.
f) With the power on, gave a few quick spins to the motor shaft with a screw driver, tried both clockwise & anti-clockwise - no dice.
f) The only thing I didn't check was the centrifugal switch. So, I decided to look at that and started opening the real well cover. It had four bolts, got three off and, wouldn't you know it, the fourth one rounded off on me :mad: - I gave up after struggling with it for 10 mins and only managed to round it further.

What are my options at this point? Did I miss anything?
- I could get a bolt extractor set and remove that rounded bolt, but what would I find inside that could be an easy & cheap fix?
- The motor board or winding could be damaged, needing repair or replacement that is beyond my capabilities.
- I could spend the $$ and have a professional look at it, but I doubt they would suggest anything other than replacing the motor or the entire pump.
- I was thinking about getting an energy effcient dual speed or variable speed motor, so maybe use this breakdown as an opportunity to upgrade the motor?

The pool is still blue but has started showing some signs of stagnation. How do I maintain it while the pump is down?
With the long weekend coming up, time is not on my side. I would like to get it fixed atleast by next weekend.

All suggestions/advice welcome.
Thank you.
 
Welcome to TFP.

Usually if the centrifugal switch fails the motor will start then blow the capacitor in a few seconds when it does not disengage the capacitor. Unless the switch failed and is not connecting the capacitor into the start circuit. So it could be your problem.

Post a pic of the motor data plate.

@JamesW @Jimrahbe thoughts?
 
bz,

I personally think you are just looking for an excuse to buy a Pentair 3 HP IntelliFlo VS pump... :) What most consider the "Gold Standard" of pool pumps.

I run mine 24/7, most of the time at 1200 RPM, and my electrical cost is less than $20 bucks a month.

While the cost is nice, I like how quiet it is... when I first got it, I had to actually touch it to make sure it was still running..

You could then start asking your neighbor's why their pumps are so loud...

Thanks,

Jim R.
 
Usually if the centrifugal switch fails the motor will start then blow the capacitor in a few seconds when it does not disengage the capacitor. Unless the switch failed and is not connecting the capacitor into the start circuit. So it could be your problem.

Post a pic of the motor data plate.
Thanks for the reply. Here is pic of the lable on the motor:

Pool-Motor-Labelx.jpg

The centrifugal switch is the only item I couldn't check, and it is bothering me. Maybe I should go get that bolt extractor set from Harbor Freight and open the back. Atleast that'd confirm if the centrifugal switch is the problem or not.

Someone on CL is selling at Century Centurion USN1202 motor for $50. I am wondering if it would fit the pump. The cross reference table from US Motors shows as UST1202 as the compatible model, but I've been looking at the specs and the only difference seems to be the dimensions.

I personally think you are just looking for an excuse to buy a Pentair 3 HP IntelliFlo VS pump... :) What most consider the "Gold Standard" of pool pumps.

I run mine 24/7, most of the time at 1200 RPM, and my electrical cost is less than $20 bucks a month.
Any excuse to get the latest & greatest ;)

The serial number on my pump starts with 21110601 - so it was manufactured in Jan 2006, 13 years old. Maybe it is time to replace the whole thing.... but that Pentair looks awfully expensive, a I think it might be overkill for my small pool. Any other recommended options? Will decide on repair replace this weekend.
 
The motor was made in April 2012. So, about 7 years old.

What is the exact voltage that you're measuring line-to-line?

The motor is a permanent split capacitor motor. It uses a "Run" capacitor. A "Run" capacitor stays in the circuit. So, there's no centrifugal switch.

Remove the power wires from L1 and L2.
Remove the capacitor.
To safely discharge a capacitor, use a 15k ohm, 2 watt resistor.
Test ohms from L1 to each of the wires that go to the capacitor.
Test ohms from L2 to each of the wires that go to the capacitor.
Test ohms from L1 to L2.


664848-3-1.png


The main winding and the start winding are in parallel. With the capacitor removed, L1 to L2 is the main winding. L1 to A is the start winding. L2 to B is zero ohms. L1 to B is the main winding. L2 to A is the main and start winding added together.

Also, check each line to ground to make sure that the windings are not shorted to ground. The reading should be O.L open line.
 
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Ok, if any of the readings is high or Open Line, then the motor is probably bad.

The motor is an energy waster. So, you would be better off going to a variable speed pump.

There might be a rebate available from the local utility to switch to a variable speed pump.

If you want to replace just the motor, you can probably go to a much smaller motor and impeller unless there's a reason that you need such a big pump.
 
What is the exact voltage that you're measuring line-to-line?
Between L1 & L2 - 218V
Didn't measure L1 & L2 individually, but I am sure power supply is good as there is a booster pump next to it for the pool cleaner and it turns on fine.

The motor is a permanent split capacitor motor. It uses a "Run" capacitor. A "Run" capacitor stays in the circuit. So, there's no centrifugal switch.

Remove the power wires from L1 and L2.
Remove the capacitor.
To safely discharge a capacitor, use a 15k ohm, 2 watt resistor.
Test ohms from L1 to each of the wires that go to the capacitor.
Test ohms from L2 to each of the wires that go to the capacitor.
Test ohms from L1 to L2.
.......
Also, check each line to ground to make sure that the windings are not shorted to ground. The reading should be O.L open line.
Good to know there is no centrifugal switch, so it must be the windings then. Here are the readings:

L1 to C1 = 1.5 Ω (varying between 1.4 & 1.7)
L1 to C2 = Starts at around 9 MΩ and creeps up slowly, went up to 13 MΩ in about 10-15 secs and I stopped.
(I also measured the capacitance between L1 & C2 and it read 1.5 nF, if that matters).

L2 to C1 = Open
L2 to C2 = 0.2 Ω (varying between 0.0 & 0.4)

G to L1 = Starts at around 8 MΩ and creeps up slowly, went up to 11 MΩ before I stopped reading.
G to L2 = Open

Ok, if any of the readings is high or Open Line, then the motor is probably bad.

The motor is an energy waster. So, you would be better off going to a variable speed pump.

There might be a rebate available from the local utility to switch to a variable speed pump.

If you want to replace just the motor, you can probably go to a much smaller motor and impeller unless there's a reason that you need such a big pump.
So, I'm guessing my motor is shot?

I am considering getting a VSP like everyone is recommending.... just that it is an unplanned expense.
Couldn't find any rebates for pool pumps from Oncor (our electricity provider). But I will drop by a local pool store and enquire, they would know for sure.

I too thought the motor & pump are a bit oversized for the pool (we just bought the house). The pool is 14 x 35, with 425 sq ft area, 3 ft depth at one end, 5 ft in the middle and 4 ft at the other end. So has just under 15000 gallons by my calculation. There are two skimmers, 5 return jets and two small water falls. Filter is a Hayward SwimClear Cartridge Filter (4 cartridges). The pump location is on a slight slope & it seems like the pump inlet is at the same level as the pool water level.

I didn't meaure the feet of head as I don't know the layout of the pipes (2-in PVC). And can't do the measuring with guages now as the motor is dead.

What size pump would be ideal for this? How do I go about figuring it out?
If you have enough information, please recommend a couple of pumps I should consider.

Thanks.
 
What is the ohm reading between L1 and L2?

The voltage is too low, especially with no load.

I would check the voltage at the breaker and the incoming main line.

I would also load test the line by putting a 10 amp load on the line and watching the voltage to see how much it drops.

I would use a stove element. It's a simple resistive load. You can use whatever you have available.

Note: Don't do anything that you are not sure that you can do safely.
 
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What is the ohm reading between L1 and L2?
The voltage is too low, especially with no load.
I would check the voltage at the breaker and the incoming main line.
I would also load test the line by putting a 10 amp load on the line and watching the voltage to see how much it drops.
I would use a stove element. It's a simple resistive load. You can use whatever you have available.
Note: Don't do anything that you are not sure that you can do safely.
Sorry, forgot to post - No ohm reading between L1 and L2 - reads O.F (Open or Out of Range).

The 218V reading was with load (wires still connected to the motor). I measured now with the wires disconnected and it reads 243V.

I don't have a stove element or anything similar to do the load test. Plus, I am nervous handling the exposed electrical wire in the yard - rather not do anything with the power supply on.

Re USN1202 vs UST1202. Both will bolt onto the pump. Depending upon whether the mounting bracket has an adapter you can add or remove to match the diameter of the motor determines it’ll fit. It’s part 23 on the diagram. It has a piece that can be added / removed to adopt to the motor.

Thanks for the llink to the diagram. I checked, the motor is sitting directly on the mounting bracket (part 23) - no adapter in between.
The current EB130 motor is 6.5" dia while the USN1202 is 6-5/8" dia, so I am thinking it might fit?
 
Ok, I would say that the main winding has failed.

The no-load voltage is good. So, you shouldn't have a problem.

If you want to replace the motor, I would suggest replacing the impeller and going to a smaller motor unless you need the flow for some reason.

I think that you could probably go to a 1.0 hp total hp motor.

If you want a new pump, I would suggest the Intelliflo VS or Superflo VS depending on the amount of flow you want.

To go to a 1.0 hp total hp motor, you would need the following:

SPX3000BN.....Diffuser
SPX3005R........Wear ring
SPX3007C........Impeller
SPX1600R........Diffuser gasket
SPX3000T........Housing gasket
SPX1600Z2......Seal.
 
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Ok, I would say that the main winding has failed.
The no-load voltage is good. So, you shouldn't have a problem.

If you want to replace the motor, I would suggest replacing the impeller and going to a smaller motor unless you need the flow for some reason.
I think that you could probably go to a 1.0 hp total hp motor.

If you want a new pump, I would suggest the Intelliflo or Superflo depending on the amount of flow you want.
What is the model number of the current pump?
Thanks for confirming that the motor is dead. I will replace it.

The pump is Hayward SP3015X20AZ Super II Inground Pool Pump. Serial no. starts with 21110601 (so, manufactured in Jan 2006?). Might as well replace the pump along with the motor.

Would the SuperFlo VS with 1.5 hp be a good fit for my pool? I am not sure how much flow I need. I just want the pool circulating & filtering properly. I vacuum maybe twice a month, and need some flow for that?

Also, I have 2-in pipes and the SuperFlo VS seems to have 1.5-in ports. Would there be any issues if I use reducers to connect?
 
The Superflo VS should be good for you. The unions take a 2" coupling to the outside. So, that matches your plumbing.
Thanks, looks like I will be going with the Superflo VS.

Just got back from Leslie's pool supply. They have it for $970 + taxes and $99 for installation only if I put in the order today (8/31). They say the $99 installation offer expires today, and it is $250 from tomorrow.

I asked about price matching the sub $700 prices I found online and they refused. Said Pentair does not offer any warranty for online purchases, and that the pump has to be installed by a professional to get the 2-year warranty. Is that correct?

I was thinking about buying it online and installing it myself. But if Pentair doesn't offer warranty to owner-installed pumps then I am not sure if I should risk it.
 
Thanks for the llink to the diagram. I checked, the motor is sitting directly on the mounting bracket (part 23) - no adapter in between.
The current EB130 motor is 6.5" dia while the USN1202 is 6-5/8" dia, so I am thinking it might fit?

According to Regal Beloit ( the company that owns Century ) the USN1202 is 6.42” diameter. My guess is they’re the same diameter.

Other than cost, the dual speed and variable speed motors are better.
 

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