What is the most quiet return pumps?

BlueAbyss · #1 05-23-2009, 09:13 AM

Quote:

Originally Posted by sphelps

I would assume the quiet ones are also synchronous. Correct me if I'm wrong but I believe this simply means the frequency of the AC motor is consistent and therefore always turns at the same speed. This would likely be consistent with any magnetically driven pump. I'm fairly confident that these two pumps are identical, meaning the same motor and impeller.

I think synchronous refers to the rotor (impeller) rotating at the same speed as the rotating magnetic field in the coils, which I assume is where the electronics come in.

It's good to know that this pump is not quiet. It is efficient though...

banditpowdercoat · #2 05-23-2009, 12:10 PM

IN truth, All Mag drive style pumps are Synchronus. Meaning they have a Fixed magnetic field on the rotor. Most motors, (external pump style motors, AKA Squirrel cage) the electricity has to induce a magnetic field in the rotor. This will result in "slip" between the speed of the Electricity in the stator and the rotor. Synchronus motors use some form of magnet, be it permanent or electromaglet for the rotor, so the slip is not seen.

What I think they are talking about for submersable pumps is the direction. On a single phase motor(common house hold electricity is single phase) If there is not some sort of starting device. Be it a start winding, a start capacitir, whatever. The rotor will just occilate and not acctually turn. Thats why the smaller MAG pumps, the impeller is "Loose" on the rotor. The rotor will jiggle back and forth, CW, CCW untill it gets momentum enough to spin around, then when spinning, the electricity keeps it going. With the directional style impellers/housings, the motor needs to allways spin in one direction. this, the need for a start winding.

I can get into ALOT more detail if needed, but I got to go to work now

sphelps · #3 05-23-2009, 02:59 PM

Thanks for the info bandit.

So for external pumps there are a few options for high flow and low noise. But are there any other submersible pumps other than RD that can push over 2000gph quietly?