Replacing motor with two-speed motor

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B

bignick

0
May 23, 2008
83
Northern California
My pump (Sta-Rite Max-E-Pro P6E6E-206L, 1hp, 1.65sf) has been getting noisy the past year, so I thought now would be a good time to upgrade to a two-speed pump. The pump is only 6 years old and since I don't want to mess with the plumping, I want to just replace the motor. My Aqualogic controller appears to be compatible with two-speed pumps and will switch to high speed when the solar kicks on.

Option #1: Reading the manual, Sta-Rite makes a two-speed pump in the same family. The only difference is the motor, impeller and diffuser. sO I could create the same pump by purchasing the same motor (Century UQS1152R, 1.5hp, 1.1sf), impeller and diffuser. Why is the impeller different? Does it have to do with it being up-rated vs full rated? What if I only changed the motor?

Option #2: Century has a newer pump (B2982, 1hp, 1.65sf) which has even lower power consumption. The only caveat is that it is a 56Y pump, but I think I can use the base for the 3hp pump which is also 56Y. If I go this route, can I leave the impeller/diffuser as-is?

I'll probably have more questions when it comes to actually replacing the pump, but I have one question. In the manual, it talks about installing the ceramic seat into the seal plate. Is the ceramic seat part of the shaft seal kit? I've seen pictures online; is that the piece with the spring? I'm sure it will make sense once I open it up, but I'm just curious for now.

Thanks for any and all input.
 
If you look at the HP * SF in option 1 you will see that your old and the new are the same (1.65). You are right one is full-rated and the other is up-rated, but they are equivalent. You should not need to replace the diffuser or the impeller with that motor.

To control the 2-speed motor, you will need to use one of the AUX high-voltage relays in addition to the pump relay. Do you have a free one?
 
Crud! I read about the wiring, but forgot about it. I'm at work, so I can't check, but I think my relays are already taken (filter, waterfall pump, cleaner pump, lights). Options? I could put the lights on a separate switch, but I like being able to operate the lights via the remote. Can I add a switch to select low/high speed but still let the controller control on/off? This is a great compromise because I can just run on high speed in the summer (for the solar) and run on low in the winter. This will still save me money because I get killed during the 2-3 week cold snap when the pumps all turn on for 9-12 hours a night because of freeze protection. What type of switch do I need? Does it need to be horsepower rated?
 
If you want to keep the lights on the remote (I have a switch by the house, so do not plan to have my light relayed used for lights ... and I do not plan to pay for a remote), then you can use a manual switch to select the speed. My Superflo came with a toggle switch installed on the back of the motor.

I am not 100% sure what the requirements on the switch would be, just needs to be SPDT. I know there were some threads in the forums that discuss the switches. Try a search and let us know if you do not find anything.

The only issue could be if the controller called for solar, while you had the speed set for low. The controller would not be able to automatically switch to high ... and it will not be able to automatically run on high for priming purposes (although you should not lose prime anyway).
 
Thanks, Jason. I found a thread indicating that both hot lines should be switched for safety and a diagram showing how to wire in a DPDT switch. Living in Northen California, I don't close for the winter, but I do have a routine where I disable the controller for solar and open the drain valves on the solar panels. At that time, I would just flip the switch to low speed.
 
good deal :goodjob:

yeah, the DPDT would be a little safer. The switch that is mounted on my motor is just a SPDT, but you should not be going in there without the breaker off anyway.

EDIT: Wait. That can't be right.

EDIT2: I think you want to use a DPDT switch to on/off, but the speed selection is not wired that way. There is one "line" terminal that needs power for either speed and then the "low" and "high" terminals that get power to decide what speed the pump runs. So, I do not see how both sides of a DPDT would even be needed.
 
You're right. The thread I was reading was using a DPDT Center Off switch. With an 'off' position, you would want to switch both hot lines, but since I don't need an 'off' position, I think I can use a SPDT switch.

Just out of curiosity, I'm going to call Sta-Rite or Century and see if I can find out why there are two different impeller part numbers between the single and two speed pumps.
 
Be careful. On the motor if you just use the switch for low to high, and only time the low/hi line (to switch on/off) there is still a common that will have 120v going to it, and all through the motor until the breaker is off. This is mentioned above, but I thought it was worth repeating.

By no means is it an unsurmountable task.

On the one I just installed I had a DPDT timer for on/off, and a SPDT timer for Hi/Low. I ran a hot tap to the SPDT timer to run the timer motor, but the particular one used did not use the timer electricity to go to each pole. This allowed the timer to work, and still have a "full off" when the on/off timer says off.






I still flip the breaker. ;-)
 
Here's an update and a problem...

I just replaced my motor with a Century B2982 2-speed motor. I didn't have a spare relay in my Aqualogic controller, so I added a SPDT on/on rocker switch (it's actually a DPDT, but I'm only using one side). Low speed works fine, but when I try to start on high speed, the motor buzzes for 2-4 seconds and then shuts off. It sounds like it's trying to start sort of like a low battery trying to start a car. After a few more seconds, you can hear a click which I assume is the thermal overload protection resetting itself. I did get it to start on high speed once to get the pump fully primed, but that's it. I haven't tried switching speeds while the pump was running because I didn't know if that was okay. If it's okay, I can try switching from low to high as its running and see what happens. Another thing I could try is removing the switch and connecting only the high speed line. The switch I bought is rated 20A/208V, 2hp.

Anything else I can try? Because low speed works, I'm assuming the wiring and start capacitor is okay (?).
 

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To me it sounds like the wiring must not be right (although odd that it worked once). When wired correctly, there is no problem with switching speeds while the pump is running ... my controller does it all the time.

Add some pictures / wiring diagrams of the wire paths / connections.
 
It sounds like you have the high speed wired wrong.
Can you tell us how it's wired?

One leg of the power should be wired to the COM terminal in the motor and the other power leg should be hooked to the center post on the switch.
Then the low speed wire should go from one of the remaining posts on the swith to the LOW terminal in the motor and the high speed wire goes from the other post on the switch to the HI terminal in the motor.
 
Update:

I emailed the techs at the motor manufacturer. He thought it might be the start capacitor. I checked and rechecked the wiring. While the pump is running on low speed, I can flip the switch and it runs very smoothly and quietly at high speed. I'm going to pick up a replacement cap and hope it works.
 
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