Hayward 2 speed pumps
- Thread starter cj133
- Start date
Hi James,
I had come across that, but I interpreted it as being the recommended flow for a pipe size rather than the skimmer.
- Oct 25, 2015
- 5,854
- Pool Size
- 28000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
I think you might be mixing up 2-speed and variable speed motors. Two speed motors are induction motors which inherently consume more power but they can still result in power savings if you're able to run the lower speed a significant amount of time. Variable speed motors are permanent magnet motors. These can reduce power dramatically because you have essentially infinite speed choice and they are more efficient since they don't have to create the magnetic field. Even though they are way more expensive the added cost is usually paid out in a year or less. Here's a great report that explains in more detail.
I hope this is helpful.
Chris
Hi Chris,
No, I'm not mixing them up.
My assumption based on what I've read is that it's not the motor saving energy but rather the pump. I guess because the pressure of the entire system drops substantially.
- May 3, 2007
- 18,169
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
@cj133, your are correct in that a two speed motor pump will reduce energy use by ~75% on low speed. A VS pump would save even more at the same flow rate.
Just throwing this out there out of curiosity.
What's more efficient.
A single speed pump connected to oversized piping and an oversized filter
Or a 2 speed pump running in low speed, connected to the same filter and piping as above moving the same volume of water?
I'm assuming the first scenario would be more efficient overall.
What's more efficient.
A single speed pump connected to oversized piping and an oversized filter
Or a 2 speed pump running in low speed, connected to the same filter and piping as above moving the same volume of water?
I'm assuming the first scenario would be more efficient overall.
- May 3, 2007
- 18,169
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
That is not really a possible scenario because there is no two speed pump (residential pool pump) that will produce the same flow rate as a single speed on low speed. But theoretically if there were, then the single speed would be more efficient because a two speed's low speed winding is about 50% less efficient than a primary winding.
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Hi Mark,
Are you sure about that number?
I believe this is the type of motors these pumps use :
Dahlander pole changing motor - Wikipedia
- May 3, 2007
- 18,169
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Yes positive about the number and the motor design. For a residential pool pump motors there is separate winding for low speed that uses finer wire which has more I2R losses and efficiency drops by ~50%.
The Dahlander is a 3-phase motor design.
The Dahlander is a 3-phase motor design.
Hi Mark,
Interesting.
Are they still considered Dahlander motors? Or is it an entirely different design?
- May 3, 2007
- 18,169
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
They are not a Dahlander design.Two speed and single speed pump motors are single phase induction motors. Single speed motors have a primary 2-pole winding and a secondary 2-pole starter winding, 90 degrees out of phase which is why a capacitor is required for the starter winding. Two speed motors have the same windings as a single speed but on top of those windings is a 4-pole winding for the lower speed. They have to pack it all in the same motor profile so smaller gauge wire is used for the low speed winding which is why the efficiency suffers.
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Mark,
Thank you for taking the time to respond to my questions. I know this isn't normal "pool talk" but I was curious about these the moment I found out they existed. I didn't know there were motors that could switch between 2 and 4 poles. I can certainly see how variable speed pumps surpass the 2 speed ones now.
I need to figure out what I'm doing with main drains as well as single vs multiple returns.
The good news is, I have plenty of time to figure things out. The bad news is I'm sure even after I make up my mind as soon as it's all installed I'll wish I had done it differently.
- Oct 25, 2015
- 5,854
- Pool Size
- 28000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
OK, that's great. Also keep in mind that not every pool can use the low speed because it won't create enough head at the low speed. That's the case for my home with a solar heater. So the only way for me to benefit is a VS pump.
Chris
- Oct 25, 2015
- 5,854
- Pool Size
- 28000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
Mark,
I read your post called Hydraulics 101 a while back. It's one of the best summaries of hydraulics I've read and excellent resource for all of us. Thanks so much for taking the time to do it.
Chris
Totally off topic, but does anyone know what the story with the Intex sand filter setups is?
As in, do they actually flow as much as they claim? I don't see how those tiny filters can pass that amount of volume without severe head pressure.
As in, do they actually flow as much as they claim? I don't see how those tiny filters can pass that amount of volume without severe head pressure.
- May 3, 2007
- 18,169
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I didn't think the rating for the Intex filters was all that high. The largest I have seen is 3000 GPH which is only 50 GPM. But the true performance is lower than that when you add the lines and skimmers and returns. Probably closer to 40 GPM.
Sorry for the late reply.
50gpm is a lot for such a tiny filter considering Hayward says their 250lb filter which is much larger is only good for 54.
The size and cost difference is enormous.
@JamesW Do you have any thoughts?
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- May 3, 2007
- 18,169
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I believe the rating you are looking at is for public pools and is not where the filter would get damage or anything like that. Sand filters are very robust and can handle being over driven by quite a bit.
Also, the 3000 GPH filter is a 1.4 sq-ft filter which normally would have a rating of around 35 GPM (@ 25 GPM/sq-ft) and that is where the flow rate would probably end up for that pump in a typical installation so I don't think they are really over driving the filter much if that is your concern.
Also, the 3000 GPH filter is a 1.4 sq-ft filter which normally would have a rating of around 35 GPM (@ 25 GPM/sq-ft) and that is where the flow rate would probably end up for that pump in a typical installation so I don't think they are really over driving the filter much if that is your concern.
Ok, So what is the reasoning behind using a 2 speed pump and running it in low because that's enough for the pool rather than buying a single speed smaller pump?
133,
A 2-speed pump gives you the option to run at high speed if needed to run a vacuum, or pool cleaner, or a waterfall, etc..
The other thing is noise... a 2-speed pump on low is much more quiet than when on high..
Thanks,
Jim R.
A 2-speed pump gives you the option to run at high speed if needed to run a vacuum, or pool cleaner, or a waterfall, etc..
The other thing is noise... a 2-speed pump on low is much more quiet than when on high..
Thanks,
Jim R.
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