Backwash procedure for pool with 2 filters

[JPMorgan]

The concern I have is what does that actually mean? Is it hydraulically inefficient because it should be 4”, 6”, 8” in diameter?….. or because it has too many restrictive fittings….or because anything? They have not defined the actual root cause, which leaves you with a potential fix that could mean re-plumbing everything depending on the knowledge/expertise of the diagnostician

Bsaed on all the feedback here, problems with the pump are my primary focus and the first thing that I will have them check. With respect to the plumbing, here is the full description of what the PC said about the "hydraulically inefficient" plumbing... "The plumbing configuration is not hydraulicly efficient as the system is bushed down from 3” to 2” pipe before the system splits off the two filters."

I think this is the section of the plumbing they are referring to. Does that make sense.... or is this not likely to be a source of the problem that needs to be ruled out?

 

[JamesW]

Are you saying when a PC sells you this type of pump, they can't install it and have to bring in a Commercial Electrician to do that?

We are doing diagnostics, not a new installation.

Also, most pool service people are not familiar with three phase power and they should have a qualified electrician provide power.

If your pool people are so qualified, then why are you having all of these problems?

Their job is to make things work correctly and they are not able to do that, which is why you are having to try to fix it yourself.

If they knew what they were doing, then everything would be working correctly.

 

[mas985]

Bsaed on all the feedback here, problems with the pump are my primary focus and the first thing that I will have them check. With respect to the plumbing, here is the full description of what the PC said about the "hydraulically inefficient" plumbing... "The plumbing configuration is not hydraulicly efficient as the system is bushed down from 3” to 2” pipe before the system splits off the two filters."

I think this is the section of the plumbing they are referring to. Does that make sense.... or is this not likely to be a source of the problem that needs to be ruled out?

View attachment 649281

I think we covered already. A 2" to 3" bushing has about the same head loss as a 45 bend so not much at all. That is not the problem.

 

[JPMorgan]

Can you show a video of the operation with the rotation being verified?

See video below. The shaft is definitely rotating counter-clockwise viewed from the wet end of the pump. (See pics below.) What does this tell me?

Shaft spinning counter-clockwise from this view...


Video taken from the left side of motor. Shaft spins toward me.

 

[Lake Placid]

From my understanding from your pics, it’s rotating correctly.

 

[JPMorgan]

Their job is to make things work correctly and they are not able to do that, which is why you are having to try to fix it yourself.

If they knew what they were doing, then everything would be working correctly.

Just to clarify.... I'm not going to be fixing this. I'm just trying to pinpoint where the problem most likely lies in order to avoid the HOA spending money on things that are unnecessary, i.e., filters, multi-port valves, re-plumbing, etc. No one here understands anything about pools (and my knowledge about these "hydraulic" issues is very limited), so we are "at risk" of bad advice from the PC. The comments here point to the pump or the flow meter being the issue.... most likely the pump. In the proposal we received from the pool company that did the installation of the new Controller last year, they didn't mention either the flow meter or the pump as the issue. At this point, I'm thinking you would probably recommend working with another pool company to address the flow rate issue, since their diagnosis and proposed "fixes" seems off base. We are meeting with them on June 3rd to review and discuss their proposal and I will be bringing the information I have received here to that meeting. We'll see how it goes...

 

[mas985]

It should not take you much time or effort to remove the motor from the wet end. You don't need to be from a PC to do this as many on this forum do not work in the industry and do it all the time. Just remove those silver bolts that hold motor onto the wet end.

 

[JamesW]

As long as it matches the arrow on the pump housing, it is ok.

You can use a contact or non-contact tachometer to check the RPM.

If you have the right rotation and the right RPM and the right parts, the pump should match the pump performance curve.

 

[JPMorgan]

View attachment 649364

From my understanding from your pics, it’s rotating correctly.

Yes.... I agree. It is rotating clockwsise when viewed from the motor-end of the pump. James W..... does that eliminate the electrical issues you noted in your previous post or could there still be problems there?

 

[mas985]

 

[JPMorgan]

As long as it matches the arrow on the pump housing, it is ok.

I will double check that.... 99.9% sure it is rotating correctly.

 

[JPMorgan]

It should not take you much time or effort to remove the motor from the wet end. You don't need to be from a PC to do this as many on this forum do not work in the industry and do it all the time. Just remove those silver bolts that hold motor onto the wet end.

I think I will let the pool company handle this, but I will be present when they take it apart so they can show me the internal parts. I hope that impeller is stamped with the part #. Otherwise, how would I know if it is the correct one?

 

[JamesW]

 

[JamesW]

 

[JamesW]

James W..... does that eliminate the electrical issues you noted in your previous post or could there still be problems there?

Still need to verify RPM.

 

[mas985]

In order for a change in RPM to account for the lower flow rate, the slip of the motor would need to go from 4% to 35%. This would require a significant load change, which could happen, but the consequence of the higher current would be either a trip of the thermal limiter or the breaker. So I don't see how this could account for the flow rate change.

 

[JamesW]

It's a three phase motor, so it might be a problem in the motor.

I would want to verify to eliminate it as an issue.

Not that hard to check.

 

[JamesW]

I hope that impeller is stamped with the part #. Otherwise, how would I know if it is the correct one?

Get the exact dimensions of the parts for comparison and measure with a caliper.

 

[JPMorgan]

A questioin was asked earlier about the size of the pipe coming from the pool into the pump. When I measurethe diameter I get 3 1/2". I don't see anything stamped on that section of pipe (becasue the sections are quite small), but on the pipe coming out of the pump it is stamped 3".... but to me that pipe also measures 3 1/2".

 

[mas985]

A questioin was asked earlier about the size of the pipe coming from the pool into the pump. When I measurethe diameter I get 3 1/2". I don't see anything stamped on that section of pipe (becasue the sections are quite small), but on the pipe coming out of the pump it is stamped 3".... but to me that pipe also measures 3 1/2".

View attachment 649388

Inner diameter is 3"