Trouble getting seal plate back into Northstar Pump

joelq

0
Mar 29, 2007
54
Hi all -

I am replacing my Hayward pump motor with a V-Green EVO variable speed motor. I got this from inyopools and they sent new o-rings along with the motor.

I've gotten everything re-assembled to the point where I have to insert the diffuser+impeller back in and the seal plate flush with the pump body. See attached pic. I'm unable to get enough force to get the assembly back in there. The new o-ring just makes too tight of a fit. I've lubed everything, and even warmed the o-ring in hot tap water. Anyone have any tips?

Thanks!
 

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Hi Joel. Be sure to check the installation of the shaft seal- maybe a relic of the old one is stuck on the impeller and making it a little too long? They can seem to meld into the impeller a little and appear to be part of the structure, but a little shove can help remove it (attach images of the shaft seal installation if you can).
 
I have a Northstar and I know exactly what you are talking about. The seal plate is extremely difficult to seat proper. What I have done in the past that seems to work well is to fully lube the large o-ring and then when you get to the position in the photo, start to gently rock the motor back and forth to move the two pieces together. Also, I found that it is easier to put the inlet downwards on a board with the motor straight up so I could put my weight into pushing it down.
 
Man, what a pain it was, but I finally got it in. I ended up doing exactly what @mas985 suggested and propped-up the filter on its inlet end (motor back-end up) and sat on it, rocking side-to-side. That popped-it in partially, then I used a combination of ratchet straps and blocks of 2x4 to get the rest of the plate in.

I sure hope I don't find any leaks because I don't want have to do that again.

@DavidArmenB - yes, the o-ring was the right size. I had also tried re-installing the seal plate with the old o-ring and encountered the same resistance.

@InyoRich - I did notice the new motor had a collar that stuck out further than the original motor, preventing the motor mounting plate to sit flush. I got some stainless steel washers (maybe 1/16" thick?) to act as spacers. At the end of the day, though, I'm not sure this was significant enough to have caused my difficulties.

A couple follow-up questions:

1. Are the washers OK? I hope so, as I don't want to have to undo the motor again, Haha.

2. Do my bonding wires look mounted correctly (see attached pic)? They're pretty securely held by the screw, so I think they're ok, and there's continuity pre- and post- the motor.
 

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Hi Joel, the new motor shouldn't need the spacers/washers - I haven't heard of any issues with the variable-speed motors having a longer collar on them, since it is a standard mounting flange. I'm guessing it won't make a difference as long as the impeller spins freely.

It is not recommended to use the bonding lug as a splice point, so head to your local hardware store and purchase a copper split bolt like this one to join the bonding wires together. This will be much safer in the long run. 1702310335428.png
 
Hi Joel, the new motor shouldn't need the spacers/washers - I haven't heard of any issues with the variable-speed motors having a longer collar on them, since it is a standard mounting flange. I'm guessing it won't make a difference as long as the impeller spins freely.

It is not recommended to use the bonding lug as a splice point, so head to your local hardware store and purchase a copper split bolt like this one to join the bonding wires together. This will be much safer in the long run. View attachment 544190


Ahh, excellent. I'll do that ASAP! Thanks, @InyoRich!

Understood about the washers/spacers. I'm sure you're right, but check the attached photo I took comparing the two. The new motor definitely sticks out more, and though there's a large enough hole in the motor mounting plate, it affects everything downstream on the shaft. But either way, if the washers are ok, I'm cool leaving it as is!

Thanks, again!!


PXL_20231209_214259686.MP-small.jpg
 
Very interesting - thank you for that picture! What is the model # of the old motor (is the label legible)?
Amazingly, the motor label is pretty well intact. Here you go!

Btw - I hope you don't mind me DM-ing you some follow-up questions. Mostly schedule configuration, etc. Just let me know if you prefer I keep it to the web site support channels.

PXL_20231211_201848072.jpg
 
Either/or is fine by me - I'll guarantee that I am far from the smartest person on this forum!

I'm disappointed that the new motor has that additional little snout and doesn't quite fit onto the original motor mounting plate. We will certainly check to see if we should continue to recommend that motor as a replacement for the OEM style.
 

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Ahh, excellent. I'll do that ASAP! Thanks, @InyoRich!

Understood about the washers/spacers. I'm sure you're right, but check the attached photo I took comparing the two. The new motor definitely sticks out more, and though there's a large enough hole in the motor mounting plate, it affects everything downstream on the shaft. But either way, if the washers are ok, I'm cool leaving it as is!

Thanks, again!!


View attachment 544199
Using washers changes the position of the impeller in the pump. It will likely increase the pressure the seal parts have against one another. Also, the position of the impeller in the diffuser will be different.
 
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I did notice the new motor had a collar that stuck out further than the original motor, preventing the motor mounting plate to sit flush.
The center hole is 2" in diameter, what is the diameter of the protrusion?
I got some stainless steel washers (maybe 1/16" thick?) to act as spacers.
That should not be done and it should not be necessary.
Are the washers OK? I hope so, as I don't want to have to undo the motor again, Haha.


1702339240039.png





1702339546908.png
 
The new motor definitely sticks out more, and though there's a large enough hole in the motor mounting plate, it affects everything downstream on the shaft. But either way, if the washers are ok, I'm cool leaving it as is!
I don't think that the new motor would have a longer shaft than the older motor.

Check with the manufacturer.


 
Amazingly, the motor label is pretty well intact. Here you go!

Btw - I hope you don't mind me DM-ing you some follow-up questions. Mostly schedule configuration, etc. Just let me know if you prefer I keep it to the web site support channels.

View attachment 544205
Your old motor has a total horsepower rating of 2.4. The new has a total horsepower rating of 2.25. It may not last with the existing impeller in that obsolete NorthStar pump. Yes, that .15THP can make a difference. If you keep it, try to not run it at 3450RPM for any length of time. NorthStar motors were made specifically for that pump as they have a higher service factor. In pool motors, not all 2hp are created equal (nor any other horsepower).
 
Greetings! From the pictures Joelq sent us, it appears that everything was installed correctly so I'm not 100% sure why the washers were needed, other than the snout interfering with something. Our bottom line for him is that there are a couple of other motor options that don't have the bump-out by the shaft, so we have changed our recommended motors for those pumps on our website. I sent him a couple of different options and noted on his order the issues he had as well as the fact that we recommended it for the NorthStar, so we are happy to take care of him in the future if anything happens and he decides to stick with the motor he has.

The motor shaft length from the mounting face is the same on both motors (the old one and the new VS one), so the addition of the washers is troubling since it changes the position of the impeller. Since many of the parts for this pump are difficult/impossible to find, we have cautioned him that a new motor is probably the only option.

Our current variable-speed recommendation for Joelq is either the 2.7HP Nidec motor or the 2.7HP A.O. Smith (Century) motor so that will address any concerns with the horsepower. We are happy to send him whatever he prefers to make sure he gets everything working perfectly.
 
The new motor definitely sticks out more, and though there's a large enough hole in the motor mounting plate, it affects everything downstream on the shaft. But either way, if the washers are ok, I'm cool leaving it as is!

the snout interfering with something.
The snout part fits through the hole, so the motor should fit.

Maybe the installation was done incorrectly.

As long as the shaft sticks through the motor mounting plate the same distance, there should not be a problem.

Maybe the OP can provide a better, more detailed explanation of why they felt that the washers were necessary.

Maybe check with the manufacturer to see what they say.
 
The snout part fits through the hole, so the motor should fit.

Maybe the installation was done incorrectly.

As long as the shaft sticks through the motor mounting plate the same distance, there should not be a problem.

Maybe the OP can provide a better, more detailed explanation of why they felt that the washers were necessary.

Maybe check with the manufacturer to see what they say.
Looking at the mounting plate, the "snout" should go through. However, the sealplate, a separate item, may be hitting that part of the motor as it is installed and not allow the pump to fit together properly. The use of washers moves everything back a small amount, which will likely cause issues as that moves the impeller as well, which will, at the very least, cause the seal to be very tight.
 
Looking at the mounting plate, the "snout" should go through. However, the sealplate, a separate item, may be hitting that part of the motor as it is installed and not allow the pump to fit together properly. The use of washers moves everything back a small amount, which will likely cause issues as that moves the impeller as well, which will, at the very least, cause the seal to be very tight.
You're spot-on @1poolman1 - the snout fits through the opening just fine, but it's the other pieces that eventually cause the seal plate to not fit flush against the motor mounting plate.
 

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