Century 2 speed motor stuttering when starting on high speed

[kmerkel]

I'm waiting to hear back from Inyo on this, but I figured I'd post here too to increase the brain trust.

The pump in question. Just installed it last night, along with a new mechanical seal and the correct 3/4hp impeller.

Low speed works normally, but high speed stutters/chatters/hesitates for a few seconds on spin up before it "catches" and takes off like it should. It's wired correctly, and I don't think it's a power delivery issue since this is actually a downsize from a 1hp that was running fine.

It seems like the governor isn't properly handing off from the start to run circuits. I'm guessing this isn't normal and won't just resolve itself, unless there is a break-in period or procedure that I'm not aware of. Is there anything to check or adjust that won't void the warranty?

Here's a short video. Sorry about the abrupt cutoff, this was the first time it actually took off and that caught me off-guard.

 

[ajw22]

Have you heard back from Inyopools?

@JamesW does this motor have a centrifugal switch?

 

[kmerkel]

No response back from Inyo yet.

The motor does have some kind of centrifugal switch, but no capacitor that I'm aware of. Would it help to get a video of the contacts as it's starting?

 

[ajw22]

Post a pic of the data plate on the motor. I am curious if the motor has a cooling fan in the rear. Definitely sounds like something is loose and rattling around in the back.

 

[kmerkel]

Data plate:



I also took a another video which I'll share once it's available.

 

[JamesW]

Sounds like something loose in the impeller area. I would check that.

 

[JamesW]

The motor type is SPM.

Type: This is a code for the electrical design of the motor. For example, A. O. Smith uses “CX” to identify its PSC switchless design. Other codes are “CS” for capacitor start; “SP” for split phase and “UAK” for capacitor start/capacitor run.

Split Phase. This type of single-phase motor is used extensively in spa and jetted tubs and above ground pool applications.

Some are used on pumps on the lower end of the in ground pool market. This design has a start winding and a start switch, but no capacitors.

 

[kmerkel]

Video of what's happening on the back end.

 

[JamesW]

Looks like a defective motor. You can see sparks. Have you verified the wiring and voltage?

 

[kmerkel]

I haven't physically checked voltage, but I'm under the presumption it's fine since the old motor had no issues. Couldn't hurt to verify, though.

 

[JamesW]

If you downsized the motor without downsizing the impeller, you are overloading the motor.

 

[kmerkel]

The impeller was downsized with the motor, so I'm good there.

 

[JamesW]

Check the input voltage and make sure that the wiring is correct.

 

[kmerkel]

At first I thought I wired it wrong, too, but it all checks out.

Voltage is good, over 110V when it's chattering and right at 110V once it's actually up to speed on high. Just for sake of argument, I doubled up the conductors from the breaker panel with a spare wire to rule out brief voltage drops that my meter couldn't detect, but that didn't make a difference.

 

[RDspaguy]

And it runs fine in low speed?
Did the new pump come with the cord attached, or did you install it? Can you post a pic of the wiring at the pump?
If you didn't wire it wrong, get a new one. That one is defective.

 

[kmerkel]

Yep, low speed works perfectly.

The switch came separately with the new motor, and the cord was reused from the old motor. The hot is connected to the open spade on the switch, I just had it pulled off to get a better angle.

 

[mas985]

Sounds like a governor issue to me. Probably a spring popped off. Since it is new, I would get a warranty claim.

 

[RDspaguy]

Wiring looks good. Bring it back and get a new one.

 

[kmerkel]

Agreed, thanks for the input. I'm still waiting to hear back from Inyo; at this point I'm not expecting anything until Monday at the earliest.

 

[kmerkel]

Update: it took about a week and two support cases but they approved a replacement motor under warranty. I'll probably take the defective one apart as a postmortem to see if I can figure out what happened.

Slightly off-topic question, is the mechanical seal single use only? Should I replace it again with the next pump, or is it OK to reuse since it's basically brand new? Also, do they take time to seat in? It looks like there is some seepage from the new seal even though I thought I did the installation perfectly.

Thanks again for everyone's help!