Voltage question with DC pump

[liteguy1]

I have a Grundfos 6 SQF-2 currently operating via 48 VDC batteries which is yielding 3.5 GPM.

Is this statement true or false:

Increasing the Voltage DC will increase the yield?

Pump is rated 30 to 90 VDC

Thank you

[inetdog]

I have a Grundfos 6 SQF-2 currently operating via 48 VDC batteries which is yielding 3.5 GPM.

Is this statement true or false:

Increasing the Voltage DC will increase the yield?

Pump is rated 30 to 90 VDC

Thank you

If this is a Grundfos pump motor that includes a DC to pulsed-AC inverter as part of its construction, then changing the applied DC voltage will not change the pump output at all. But it may allow you to use smaller wires at the higher voltage, since the current at full load will be lower.
If the pump drive had been just a DC motor with brushes, then the higher voltage would allow a higher speed and therefore a higher output power (either higher head pressure or higher flow rate.)

[SunEagle]

According to the spec sheet on the Grundfos 6 SQF-2 pump it can run on either AC (90-240V) or DC (30 - 300V). The only option to run off of a battery system is to use a CU 200 SQFlex control unit.

I did not see anywhere that a change in DC voltage will change the pump speed so I do not believe a higher DC input will have any affect unless it exceeds the control box rating of 300VDC which will shut it down for over-voltage.

There are a lot of options to run that pump from solar, a generator, batteries or wind turbine. You just have to get the right control boxes for each application.

Also there are performance curves for each pump and depending on the pumping distance and wattage of the power source provided will change the GPM though put so a higher DC voltage won't work but a bigger battery might.

[Texas Wellman]

They like voltages above 90VDC. You can go up to 300VDC. 30-300 VDC or 90-230VAC.

Looks like you are losing about 10% production, which at 3.5 gpm is only about 1/3 a gallon. Not much to be gained. Those are HR (helical rotor) pumps and are made for high head, low flow. To get more water you need to switch to a different model or go to a centrifugal. The centrifugal are much more power hungry.

[Texas Wellman]

BTW the max. wattage for any SQF pump is about 1400. They all have the same motor.

[liteguy1]

According to the spec sheet on the Grundfos 6 SQF-2 pump it can run on either AC (90-240V) or DC (30 - 300V). The only option to run off of a battery system is to use a CU 200 SQFlex control unit.

I did not see anywhere that a change in DC voltage will change the pump speed so I do not believe a higher DC input will have any affect unless it exceeds the control box rating of 300VDC which will shut it down for over-voltage.

There are a lot of options to run that pump from solar, a generator, batteries or wind turbine. You just have to get the right control boxes for each application.

Also there are performance curves for each pump and depending on the pumping distance and wattage of the power source provided will change the GPM though put so a higher DC voltage won't work but a bigger battery might.

Yes, Originally I had this setup with 4-12VDC batteries running through the CU 200FLEX. I found that this wasnt quite enough oomph, so I added two batteries and now running 70-75 VDC which has made a hugh positive impact. The pump sits at 350 feet and gives me 3.5 GPM when measured into a 5 gallon bucket. So as of two days ago we are completely off grid for water. There was no increase in GPM before and after the two battery additions.