B&G Circulating Pump

Jay_18

I had found an altered B&G pump coupler and the 3 phase motor running in the opposite direction of the arrow stamped on the volute. A new coupler was installed and the motor is now running correctly. My question is this, how much flow in percenage is lost in having the pump run in the wrong direction?

Empire_2

B&G

In my opinion you lose all your pumping because the impeller is designed to turn in only one direction. Also, if the motor was running in the wrong direction how did changing the coupler correct this problem?

Tom Blackwell

It depends on the design of the impeller; the angle of the internal runners. Low head pumps like the B&G will typically pump 40% or so running in reverse. Have seen air handlers running backwards that had been that way for 10 years. Have also run across large B&G pumps with the impeller installed backwards on the shaft-very noisy.

Kal Row

backcurve works and is quieter...

a centrifugal pump works by pushing the fluid around in a circle until the centrifugal force spins it out creating pressure differential

Impellor or fan blades that are “backcurved” ie with the outer edge behind the rotation, don’t cup as much fluid and loose flow and head ( I think it’s 1/3rd flow and 1/2 head don’t hold me to those numbers – it’s many years since I studied flow theory) , but operate much quieter, especially in a cavitating environment – because the fluid expansion follows the vane space enlargement – and the inside edge of the vanes, angle into the fluid aerodynamicaly

For air handlers where noise is a real issue, it’s very popular

you don’t loose as much flow as you might think, since the outer vane area is larger, the fluid in that has more mass and thus greater centrifugal force

I have seen designs where forward is bad because of bounce back in the discharge area

oil-2-4-6-gas

was this pump a 60 series b&g on a Laars,Raypak unit---they have special impellars -specific to them ----

jim lockard

Why

Why was the motor running backwards and what action caused it to run forward in the direction of the arrow? Thanks J.Lockard

Jay_18

I reversed the rotation via the wiring.

Jay_18

No this was 1 of 3 B&G pumps on a piping manifold for a church floor radiant system. Two of them handle the main floor of the church and 1 handles a loft area.

Jay_18

Can't anwser why it was running in the wrong direction,but based on the return water temperature something didn't seem right. Two of three pumps on the system were running in 1 direction and a new pump installed a year ago was running in the opposite direction. I suspected the new pump to be miswired until I saw the arrows on each volute indicating the correct rotation. As it turns out it was 1 of the old pumps that was running in the opposite direction until I corrected it.

Weezbo

you know ,it is interesting...

just a week ago or so, a guy was checking a system in a church and i suggested he turn the pump around small world maybe satan is guiding the minds of the people installing recirc pumps in churches recently

STEVE N

Jay

> Can't anwser why it was running in the wrong

> direction,but based on the return water

> temperature something didn't seem right. Two of

> three pumps on the system were running in 1

> direction and a new pump installed a year ago was

> running in the opposite direction. I suspected

> the new pump to be miswired until I saw the

> arrows on each volute indicating the correct

> rotation. As it turns out it was 1 of the old

> pumps that was running in the opposite direction

> until I corrected it.

STEVE N

Jay

3 phase motors will run the wrong way. Its easy to fix. switch 2 of the wire legs position at the pump, and it will change rotation.

Steve