March Pump Controllers

[Archie]

Gday everyone,
A quick enquiry today what do most people use to control the flow on their march pump. A 240v Dimmer Switch or something different.

Cheers
Archie

 

[razz]

Something different Archie, a valve on the outlet.

 

[Archie]

oh yeah good idea haha i thought it may destroy the pump but i guess if it can handle back pressure it wont matter will it

 

[mika]

Do a search, this has come up a few times recently. As they're a centrifugal pump, throttling the outlet is fine.

 

[Archie]

has anyone used a pond pump for there system before

 

[goatherder]

I'm not sure it's to do with it being a centrifugal pump - it's to do with the pump head being magnetically coupled to the motor. When the outlet is throttled the magnets decouple and the motor can still turn and not burn out.

As for pond pumps, there aren't too many HBers using them to move hot liquids around. I think the main problem is keeping the motor cool enough. I use a pond pump for circulating ice water through my chiller. For hot liquids I use a march pump.

 

[mika]

Centrifugal shaft driven pumps can be throttled as well. Only danger with big horsepower pumps is that the impellor sits there spinning and all that energy has to go somewhere. So the water heats up, some bypass back to the inlet to keep them cool, but left unchecked they'll melt the impellor or seals out of the pump.
No such dramas for our application, throttle away.