Replacement motor smells of smoke, less than 30 days after original smoked. WTH?

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Original motor specs, a USQ1102: USQ1102 - Buy AO Smith Pool Filter motor - $135.00

New motor is a SQS-1072: http://www.lockewell.com/pdf/aosmith/aosmith_sql_sqs_uqs.pdf

FWIW, the photos in that picture don't match up. My motor has a capacitor mounted to the top, but in that PDF, it doesn't show that.

What would/do I need to check with the capacitor? Considering that I have a new motor on the way (arriving on Friday), should I even bother checking it?

It's hard to tell what's going on with the wiring because I think something is shorting out inside the motor. I removed the low speed wire from the terminal on the timer, but the wire is still energized (something is feeding back voltage from the motor to the timer - there should be NO voltage present on that wire!)
 
mgarf33 said:
With that kind of current, it sound like you have 120v supply voltage.
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Definitely 240V. Just verified that the main lugs of the house panel feed a sub-panel in the basement, and the wires to the pool run out from there. It's most definitely 240V (238 at the pad.)

FWIW, I know that's a horrible way to connect a sub-panel. The electrical panel in my house is ancient and nowhere near code.
 
MitchRyan912 said:
It's hard to tell what's going on with the wiring because I think something is shorting out inside the motor. I removed the low speed wire from the terminal on the timer, but the wire is still energized (something is feeding back voltage from the motor to the timer - there should be NO voltage present on that wire!)
Click to expand...

There will be voltage on that wire as it is connected to the stator inside the motor at a different point on the windings. That is basically how multi speed motors work. There is different taps along the winding to make it longer (faster) or shorter(slower)
 

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I took the pump out of the system and disassembled it all to inspect the parts. It looks like the motor spindle is fine (maybe?) but the seal thing on the impeller looks a bit crooked. I see what might be a bit of damage to a few other parts that I never noticed before, like as if something snuck through the basket and into the pressure side of the pump.

Anything else I ought to be looking for while I still have the motor? I'm about to hook the original motor up to just the power, to see what kind of amp draw it's using (for comparison.)
 

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Old motor pulls this much before shutting down, dang near immediately after starting, making a horrendous noise in the process:

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That's not good. 45A??? Note: the motor wasn't hooked up to anything, it was just the bare motor.
 
Nice, glad to see you bought a Fluke. Some will say they're over priced, but I think they're worth the investment.

Yeah, it definitely looks like you have a bad case of binding issues. Someone may want to correct me, but that looks like classic signs of cavitation damage. Basically you're having mini water implosions inside the pump, tearing it apart from the inside.
This means you need to have a serious look at your plumbing, and you'll probably need to replace some of the wet end parts that are damaged.

As for the motor drawing high amps, well, looks like it's a good thing you're replacing that as well. Probably over heating the bearings.
When the motor doesn't spin fast enough the total impedance is lower. This means higher amps, until speed increases which increases inductive reactance.
High amps are also a sign your aux winding or run cap is failed as well.

A good way to check the speed is to download a tachometer app on your cell phone. It uses the camera flash as a timing strobe light.
Draw a vertical line on the motor shaft and check the rpms. The cell phone app may not be super accurate, but it will get you close. Probably not going to make a difference in changing the motor, but it's always interesting to check.
 
I just borrowed the Fluke from my FIL's work. I'd definitely love to own one of these, but a 325 is too much $$$ for me.

Is this cavitation damage enough to render this wet end useless? If so, I've got a darn nice 2-speed motor, but no usable wet end, and I'm not sure I want to risk blowing up another motor if the damage could prevent the motor/pump from working.

Should I be looking at getting a new single speed pump w/ motor that I could upgrade it with the 2-speed motor I have? It looks like it'd cost me about a couple hundred bucks to replace the parts that might be damaged, and it seems like that money would be better spent on something that definitely works.

I'm going to redo the plumbing to prevent the pump from having to work so hard to pump water up so high. That seems like a given, to help the pump get to prime like it should (I hope.)
 
mgarf33 said:
Before connecting that new motor, I would definitely check over all of the wiring, especially making sure the timer is not applying power to both speeds at the same time.
Click to expand...
This could be the problem. I hooked up the motor solely to the high speed lead from the timer (the lo speed lead was NOT connected to the motor) and got a amp load of 2.5A. I then tested the voltage from the hot lead (black wire in the timer box) and got 237V. So far so good.

I decided to check the voltage output on the lo speed terminal in the timer (while it was set to the high speed position) and it was reading 12V. I turned it to lo speed and it read 237V on the low terminal, and 0V at the high speed terminal.

Could this 12V to the low tap while it's getting 237V on the high tap be enough to screw things up???
 
Keep in mind, the low speed is a higher resistance winding than the high speed, and your meter is also high resistance.

Unfortunately, you don't have a LoZ function on the 325 meter which is a low impedance function.
This helps eliminate ghost voltage readings. Ghost voltage is basically a potential voltage with no current behind it. I would check the current on the same wire that's showing 12V. If there is nothing, it's likely just ghost voltage due to the high impedance meter, which means the 12v is nothing to worry about.

Here's an example.

Trip your gfci outlet in your bath room. Set your meter to volts. Place one lead on the hot 120v (which is dead due to the trip), and the other lead to your thumb.
What do you read???

Well, your meter shows voltage, or a potential difference, but you're not getting electrocuted, so there's actually no current flowing.
If you had a Fluke 117 with LoZ, you would see there is 0 volts from hot to your thumb when the switch is tripped.
This is because a standard meter has high impedance, known as Z.
 
Here's the thing though: there was NO LOAD on the low speed terminal in the timer. The wire for low wasn't connected to anything on the motor. The only wire connected from the timer to the motor was the black wire for high speed.

When I flipped the hi/low switch on the timer to low, the readings were 237V low & 0 high. Flipping the switch back to high, it was 237V high & 12V low.
 
Ok, gotcha. Sorry, my mind went off on a tangent.

Well, you could run a low voltage load, like a light or resistor from the low side output in series to wired ground, and see if it draws current, when high speed is energized.
Heck, you could even short it straight to ground and see if it trips the GFCI.

If it does, then I guess you found your issue. The contacts are partially welded causing both speeds to be energized simultaneously.

If not, it's just ghost voltage.
 

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