Pain in the butt MPRA6E-147L.

[Rigwald]

Hello Everyone!

I have a Sta Rite MPRA6E-147L 1HP pump on our inground pool. It is about 12 years old and has been giving me issues for the past 5 years or so. Every spring, I have to open it up and physically spin the impeller, because it seizes up during the Minnesota winter (all water drained, etc...). It has gone through a couple capacitors in the past 2 years. This spring I opened it up and spun the impeller, but when I put it back together, it won't spin. I noticed that the impeller itself doesn't seem to sit center in the hole of the diffuser. I found orange, crusty build up on the inside of the diffuser hole and I tried to sand some of it out of there.

I am thinking that it might just be time to retire the thing, bit the bullet, and buy a new pump, unless I hear otherwise from the wise people here. If I should replace, what would be an appropriate replacement? We do run a salt system and we have an booster pump for the cleaner (same age as the Sta Rite and has started to cause issues as well - I believe I replaced a capacitor last year as it began to hum and not start). The pool doesn't get a lot of use and only a couple days a year has a full load of party guests. Everything set up there is 110 (Heater, booster pump, regular pump, chlorine generator). There are no timers or anything. (Pump is normally turned on constantly.) I am not an electrician, but I am not sure there is any extra "flow" out there (for example for 220 instead of 110). I had my father, who does electrical stuff from time to time, look at it once for adding an outlet out there. He had indicated that we probably wouldn't be able to.

Your thoughts and suggestions would be greatly appreciated!

 

[karmabiker]

Welcome to tfp!

Are there any water features, spa or automatic cleaners?

You may be able to get away with a lower hp or 2 speed...

 

[Rigwald]

No water features. We have a slide, that we adjust some of the returns to get the water pressure high enough. We have a Polaris 360 cleaner. When it is in use, we turn on the booster pump.

Using Hayward's savings calculator, it said we would save between $280 and $300 a season with a variable speed pump. After reading some posts here and looking at pumps, I had the following thoughts/concerns:

1) Since we don't have a timer/management system, people have suggested that the difference in price between a 2 speed and a variable speed may be warranted, since a timing system would need to be added.

2) All of the variable speed pumps that I have seen online seem to be 220-240 volt, which would be difficult to do with our current electrical set-up. Each item (heater, pump, booster pump, and chlorine generator) are on their own breaker in a panel on the far end of the pool from the house. The power is buried and runs under the pool deck. The following two possible "workarounds" came to mind, but I am not sure how viable they are:

a) Replace current 110 pump with 220 pump, but know that whenever running the booster pump for the cleaner, I would have to turn off the heater's circuit breaker.

b) Replace the main and booster pump with a higher HP variable speed pump. Set the pump higher when using the cleaner (and closing off some of the returns to force more pressure to the cleaner if needed).

We normally have let the pump run constantly. We didn't know any better and wanted to make sure chlorine generation/circulation happened effectively. Reading here, I found out that wasn't necessary, so we could get some hefty savings this year.

Thanks for your time and insight!

 

[karmabiker]

What's the service factor on that motor?

I may have found a 3/4 hp updated 1.65 sf that will work that is 115v.

 

[karmabiker]

http://www.poolsupplyworld.com/Cent...l-and-Spa-Pump-Motor-13042A-115V/SQL1072R.htm

Then add a 3 way switch to select high or low.

 

[Rigwald]

The 3/4 HP booster is SF 1.5. The 1 HP main pump is 1.25. (I just read the numbers off the pumps. I really don't know what they mean.)

Is it feasible to replace both pumps with a new variable speed pump of a higher HP and adjust the speed when using the cleaner?

 

[karmabiker]

Ok that means the main pump and the one I suggested could be directly swapped out.

To get "real" hp multiply the advertised hp by the service factor.

Current motor is 1.25
One I linked is 1.24


I suppose you could just get one monster ... I think that might take some plumping work that is beyond my knowledgebase.

 

[Rigwald]

http://www.poolsupplyworld.com/Cent...l-and-Spa-Pump-Motor-13042A-115V/SQL1072R.htm

Then add a 3 way switch to select high or low.

Since the main issue with the current pump is the fact that the impeller is not sitting in the middle of the diffuser hole (and being restricted as a result), shouldn't more than the motor be replaced?

 

[JasonLion]

Yes, since your Polaris is designed to be run by a regular pump you can get a variable speed and adjust the speed up a little when you want to run the Polaris. Cleaners that are designed to work with a typical booster pump, like the 280/380, won't work that way. But yours is fine.

 

[Rigwald]

Considering the way the plumbing is right now, I wouldn't expect it to have to change much at all. My thought would be to simply bring the line that currently runs into the booster pump directly to the cleaner return, which is right next to all the other returns. All the returns come off the main line after the heater and chlorine generator.

 

[Rigwald]

Yes, since your Polaris is designed to be run by a regular pump you can get a variable speed and adjust the speed up a little when you want to run the Polaris. Cleaners that are designed to work with a typical booster pump, like the 280/380, won't work that way. But yours is fine.

Upon closer look at our paperwork, it is actually the Polaris 280.

 

[JasonLion]

Then it won't work. The 280 requires a very high pressure feed, which none of the VS pumps can produce.

 

[Rigwald]

Then it won't work. The 280 requires a very high pressure feed, which none of the VS pumps can produce.

Then if I get a VS pump (at 220), then I just won't be able to run either the heater or the chlorine generator at the same time as the cleaner.

Am I correct in figuring that the added cost of a VS pump vs a 2 speed is offset by the cost and hassle of trying to add a timer system?

 

[karmabiker]

From an electrical standpoint I'm not sure how you would safely make that happen without running a new circuit.

Vs or 2 speed you will need something to control the motor wether is is integrated like the 2 green (2 speed), v green ( vs ) or a vs or 2 speed motor that uses external automation.

 

[Rigwald]

From an electrical standpoint I'm not sure how you would safely make that happen without running a new circuit..

In the external panel by the heater, there are currently 4 110 circuit breakers: 1 for the main pump, 1 for the booster, 1 for the chlorine generator, and 1 for the heater. That is the means for turning each item off and on. If I swap out the 110 for the main pump and replace with a double breaker (220) for a new pump, that would still equal the same draw when the booster off (2 x 110 + 1 x 220) as the current setup draws when all 4 are powered (4x110). (Unless the math doesn't work correctly with electricity.)

 

[karmabiker]

Which 2 110 devices are going to stay hooked up? Or is there space for a 5th circuit breaker?

 

[Rigwald]

I believe there is space for the circuit breaker:



I'd certainly be open to a 2 speed pump, if it had an integrated timer and control mechanism. I believe I need to replace the entire unit, not just the motor.

 

[karmabiker]

I'm more knowledgable on the motor side not so much the pump side.

I'll have to let someone else pipe in on pump selection with integrated timers.

 

[Rigwald]

I'm more knowledgable on the motor side not so much the pump side.

I'll have to let someone else pipe in on pump selection with integrated timers.

Thank you for your help so far!

 

[bignick]

To get 220V, you need to use a 2-pole breaker which would connect to the Phase-A and B bus bars in your panel. If you only have single phase power to your pool panel, you won't be able to get 220V. If the wires are in conduit, you may be able to run all new wires, using the existing wires as a pull cord. I would remove the dead front on the panel and see how many wires are feeding the panel. Of course, take necessary precautions.