Problems after pump motor swap

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nscroggs said:
Reviving this thread again. I had a couple of ideas but none of them turned fruitful. I returned the Amazon motors and bought a new pump from InyoPools (same 3/4HP motor with 1.27 SF, for a total HP of 0.97). It did the same thing - shut off on its own after 10-15 minutes when the motor gets hot. I thought maybe it could be an issue with the wiring from the timer to the motor as it was super old and the carflex was cracked in multiple places. That also didn't solve anything outside of the comfort of knowing the wiring is new and prettier now. I'm pretty sure I've ruled out pump motor issues at this point since this would be the 4th motor I've put on it (2 from Amazon, returned those two, bought one from Inyo it did the same thing so exchanged it (again through Inyo) for a new one that also did the same thing. I suppose it's not completely out of the realm of possibility that both motors from Inyo are bad though...

I bought an amp probe and found that the motor is drawing 15-16 amps under load, whereas the label has the amperage at 13.4 (I also just realized the label says "max load 6.7/13.4", which I believe tells me that the issue is the amperage draw is too high, causing the motor to overheat and go into thermal overload protection (tell me if I'm wrong - just thinking out loud). I also decoupled the seal plate and ran the motor just long enough to get an amperage reading and it runs at 7-8 amps under no load. Once recoupled, as the pump primes and pressure builds, it steadily climbs back to 15-16 amps.

In the same vein of making old things new and solving simple things, I also went ahead and replaced the 20 amp breaker on the outside panel and the 30 amp breaker on the main panel in garage. Again, neither of which solved the issue but at least they're new and have been ruled out.

Thinking there may be a blockage in a line and trying to cover all of my bases, I got one of those clog removal bladders that go on the end of the garden hose and back flushed the skimmer, bottom drain, and vacuum lines, each individually - all of which "came back" clean - as in, no junk came out and I could feel the water coming back up the line (with the exception of the bottom drain because the pool is currently cloudy and cold and I can't see it from the top. The two jets also blow clean except the furthest jet still has small air bubbles when the motor is running (like fizz from a coke can, not large gulps of air).

I replaced seals on the pump basket lid, filter lid (Sta-Rite PTM70 cartridge filter), and the air bleed screw on top of the filter. Pinch-A-Penny recommended not messing with the bottom seal but I'm tempted to replace it anyways.

In replacing the seals, I did find a pinhole leak on the top of what they are calling the tank body (the other piece that the seal plate mates up with). I haven't plugged that and I'm thinking some JB Weld will do the trick there. Other than that, I don't see any drips or moisture anywhere else and don't hear any hissing, but it's also right at the pump so that could be masking it.

Is there anything else I should be checking?
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What impeller are you using? That motor you bought and replaced is designed for a 1/2 horsepower (.95 total horsepower) impeller load. A blocked line will not increase the amp draw of a motor. Since the pump won't be moving any water the load is less. You can't use that motor on a pump that has a 3/4hp (1.25 total horsepower) impeller in it.
 
racingiron said:
Are you still using the new impeller? Your motor is 3/4 "up-rated" which matches the original impeller. That new impeller might be putting too much load on the motor.
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I do still have the new impeller on there, but it's 3/4FR or 1 up-rated. I was under the impression that as long as the motor was equal to or greater than the impeller, it should be compatible. I still have the old one and it's a little worn but not cracked or broken, so I'll swap those out tonight and see if that makes it better. It's definitely worth a shot!

I also read somewhere that 1½" piping is the "old style" and is what I have, so maybe the new impeller is trying to jam more water through than it should considering the smaller piping?
 
nscroggs said:
I also read somewhere that 1½" piping is the "old style" and is what I have, so maybe the new impeller is trying to jam more water through than it should considering the smaller piping?
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I have a 1.6hp motor and it works just fine with 1.5” piping. Smaller motor would have an easier time.
 
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nscroggs said:
I do still have the new impeller on there, but it's 3/4FR or 1 up-rated. I was under the impression that as long as the motor was equal to or greater than the impeller, it should be compatible. I still have the old one and it's a little worn but not cracked or broken, so I'll swap those out tonight and see if that makes it better. It's definitely worth a shot!

I also read somewhere that 1½" piping is the "old style" and is what I have, so maybe the new impeller is trying to jam more water through than it should considering the smaller piping?
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That impeller, and the old one if it is the same, are 3/4hp, 1.25total horsepower impellers and require a motor of the same rating. Your are correct, if the motor is equal to or greater than the rating of the impeller it works. Your new motor is not equal to the rating of 1.25 total horsepower at the .95 total horsepower it is rated (.75hp X 1.27 service factor). That motor is a full-rated .5 horsepower motor, too small.
It will overheat and shut down, eventually quite literally burning up as the wiring inside gets destroyed by trying to run too many amps through it.
 
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1poolman1 said:
What impeller are you using? That motor you bought and replaced is designed for a 1/2 horsepower (.95 total horsepower) impeller load. A blocked line will not increase the amp draw of a motor. Since the pump won't be moving any water the load is less. You can't use that motor on a pump that has a 3/4hp (1.25 total horsepower) impeller in it.
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I have the C105-138PEB, which is the 3/4HP impeller (also got the matching diffuser). Where does the 1.25 total horsepower come from if it's 3/4FR or 1HP up-rated? Not second guessing you, just learning :). I guess 1HP up-rated it still technically more than the 0.95 total horsepower on the motor, so it makes sense thinking about it that way.
 
1poolman1 said:
That impeller, and the old one if it is the same, are 3/4hp, 1.25total horsepower impellers and require a motor of the same rating. Your are correct, if the motor is equal to or greater than the rating of the impeller it works. Your new motor is not equal to the rating of 1.25 total horsepower at the .95 total horsepower it is rated (.75hp X 1.27 service factor). That motor is a full-rated .5 horsepower motor, too small.
It will overheat and shut down, eventually quite literally burning up as the wiring inside gets destroyed by trying to run too many amps through it.
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Ahh ok. That makes sense. The original impeller was the C105-92PS which is 1/2FR - 3/4UR. I still have the original so I'll swap that one back in and see how that turns out. I'll report back!

Btw, you guys are awesome and super helpful. It's nice to find a forum with people that want to help people learn without making others feel dumb, even if the answer to a 3-month problem is as simple as putting the original impeller back on :)
 
nscroggs said:
Ahh ok. That makes sense. The original impeller was the C105-92PS which is 1/2FR - 3/4UR. I still have the original so I'll swap that one back in and see how that turns out. I'll report back!

Btw, you guys are awesome and super helpful. It's nice to find a forum with people that want to help people learn without making others feel dumb, even if the answer to a 3-month problem is as simple as putting the original impeller back on :)
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Old impeller is the proper one to use with that new motor. And it is good to see a .5hp pump in use. Don't worry about the size of your plumbing, it is just right.
And, those old Sta-Rite pumps are probably my favorites.
 
nscroggs said:
Ahh ok. That makes sense. The original impeller was the C105-92PS which is 1/2FR - 3/4UR. I still have the original so I'll swap that one back in and see how that turns out. I'll report back!

Btw, you guys are awesome and super helpful. It's nice to find a forum with people that want to help people learn without making others feel dumb, even if the answer to a 3-month problem is as simple as putting the original impeller back on :)
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Looking at the original diffuser, the copper ring in the middle is mostly deteriorated. Admittedly, I don't fully understand the science behind the diffuser but I can see that they are rated along with the impeller and motor. Is it safe to assume that I can't use the new diffuser (C1-200PA) with the original impeller since they have slightly different ratings? Or are the ratings close enough that I can use the new one until the correct replacement comes in?
 
nscroggs said:
Looking at the original diffuser, the copper ring in the middle is mostly deteriorated. Admittedly, I don't fully understand the science behind the diffuser but I can see that they are rated along with the impeller and motor. Is it safe to assume that I can't use the new diffuser (C1-200PA) with the original impeller since they have slightly different ratings? Or are the ratings close enough that I can use the new one until the correct replacement comes in?
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Don't worry about that ring too much. The diffuser you list is too large in diameter around the impeller to do what it is supposed to do.
The diffuser does two things. It does "diffuse" the pressure in the tank so that the water exits properly, but it also, because of the tight clearance around the front of the impeller, allows the pump to prime, it keeps the pressure in the tanks from forcing water out around the impeller and into the basket.
If you can get the proper diffuser, do so. It improves the pump performance a bit. It should be a C1-216P.
 
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1poolman1 said:
Don't worry about that ring too much. The diffuser you list is too large in diameter around the impeller to do what it is supposed to do.
The diffuser does two things. It does "diffuse" the pressure in the tank so that the water exits properly, but it also, because of the tight clearance around the front of the impeller, allows the pump to prime, it keeps the pressure in the tanks from forcing water out around the impeller and into the basket.
If you can get the proper diffuser, do so. It improves the pump performance a bit. It should be a C1-216P.
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I went ahead and put the original impeller and diffuser back on - the filter pressure dropped back to around 9PSI, amps dropped to 11-12, and it's been running for a solid 3 hours without turning off. The motor is hot to the touch but not nearly what it was. I can at least keep my hand on it now. I ordered a replacement ½ HP impeller and diffuser (just so it's all new) but that part of the problem seems to be solved. The water is super cloudy as I've been trying to keep the algae at bay while this gets fixed, so I'm going to let it run all night and check it in the morning!
 
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nscroggs said:
I went ahead and put the original impeller and diffuser back on - the filter pressure dropped back to around 9PSI, amps dropped to 11-12, and it's been running for a solid 3 hours without turning off. The motor is hot to the touch but not nearly what it was. I can at least keep my hand on it now. I ordered a replacement ½ HP impeller and diffuser (just so it's all new) but that part of the problem seems to be solved. The water is super cloudy as I've been trying to keep the algae at bay while this gets fixed, so I'm going to let it run all night and check it in the morning!
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After running all night, the pump is still running and the motor is cool! Thank you everyone for your support, willingness to share your knowledge and expertise, and your ideas! Now it's time to SLAM the heck out of this thing so the kids can finally go swimming again :)
 
nscroggs said:
I went ahead and put the original impeller and diffuser back on - the filter pressure dropped back to around 9PSI, amps dropped to 11-12, and it's been running for a solid 3 hours without turning off. The motor is hot to the touch but not nearly what it was. I can at least keep my hand on it now. I ordered a replacement ½ HP impeller and diffuser (just so it's all new) but that part of the problem seems to be solved. The water is super cloudy as I've been trying to keep the algae at bay while this gets fixed, so I'm going to let it run all night and check it in the morning!
Click to expand...
In normal use, a single-speed pool pump will be too hot to touch, around 140 degrees with no problem. If the motor is in the Sun the case will be hotter, but still without issues.
 
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