Grundfos 5hp

[kelvinfpv]

Hey guys,
Just had our well drilled to supply 2 homes and we hit 45gpm @ 280ft! So happy. We're both looking to go off grid solar and are trying to figure out the well pump now. I've been quoted a few different pumps. The sqflex 11gpm isn't really ideal for supplying both homes so I'm entertaining a conventional 3 or 5 hp pump. For simplicity the well may get its own solar system, I'm just not sure what to look for yet. That is where you come in. What should I be looking for from an inverter/inverters for this pump? https://product-selection.grundfos....a/25s50-26-5014526?tab=variant-specifications

 

[sunshine_eggo]

27.5A @ 230V

400% surge.

You need an inverter capable of delivering 4 * 27.5A = 110A @ 230V

That's 25,300W surge, and it needs to be a legitimate surge... Not some BS Growatt/MPPT Solar/EG4 lightweight inverter "surge" It needs to weigh over well over 100# and be able to handle that surge for a human-measurable time, not milliseconds.

As an example, my neighbor had a 3hp Grundfos, that he could run with a 6kW Sigineer-made inverter with a legit 18kW surge.

A big downside to that inverter is it burns > 100W even when not being used. It has to be turned off when not in use, or the inverter alone would have increased his average daily usage from about 7kWh to 9.4kWh. You'd likely need a 10-12kW inverter with 30-36kW surge, and it would probably burn 200W 24/7 even when not in use.

SQFlex would completely eliminate the need for a surge rating.

Have you considered above ground storage with a pressure tank and 1/2 hp jet pump for house supply? Run the SQ for however long it needs to pump the daily need and fill the tanks.

My neighbor uses that config. He runs 2 hours per week to top off his 2X 1000gal cisterns with the dedicated inverter. A pressure tank and 1/2hp jet pump running off the lower power Magnum (powers the whole house, very low idle consumption) that feeds the house

 

[kelvinfpv]

27.5A @ 230V

400% surge.

You need an inverter capable of delivering 4 * 27.5A = 110A @ 230V

That's 25,300W surge, and it needs to be a legitimate surge... Not some BS Growatt/MPPT Solar/EG4 lightweight inverter "surge" It needs to weigh over well over 100# and be able to handle that surge for a human-measurable time, not milliseconds.

As an example, my neighbor had a 3hp Grundfos, that he could run with a 6kW Sigineer-made inverter with a legit 18kW surge.

A big downside to that inverter is it burns > 100W even when not being used. It has to be turned off when not in use, or the inverter alone would have increased his average daily usage from about 7kWh to 9.4kWh. You'd likely need a 10-12kW inverter with 30-36kW surge, and it would probably burn 200W 24/7 even when not in use.

SQFlex would completely eliminate the need for a surge rating.

Have you considered above ground storage with a pressure tank and 1/2 hp jet pump for house supply? Run the SQ for however long it needs to pump the daily need and fill the tanks.

My neighbor uses that config. He runs 2 hours per week to top off his 2X 1000gal cisterns with the dedicated inverter. A pressure tank and 1/2hp jet pump running off the lower power Magnum (powers the whole house, very low idle consumption) that feeds the house

I wanted to look up the 3hp system and check the surge on that one but Grundfos site is down for maintenance. The residential victron system only surges to 20k. That seems like I'm in the wrong league with the 5hp pump. The victron industrial set would do it but that's 10,000$ before batteries, panels, and mounts. I haven't looked into above ground tanks but that seems like a headache in the winter time. (Keeping pipes from freezing )

 

[sunshine_eggo]

I wanted to look up the 3hp system and check the surge on that one but Grundfos site is down for maintenance. The residential victron system only surges to 20k. That seems like I'm in the wrong league with the 5hp pump. The victron industrial set would do it but that's 10,000$ before batteries, panels, and mounts. I haven't looked into above ground tanks but that seems like a headache in the winter time. (Keeping pipes from freezing )

His are in an uninsulated pump house. Temps go as low as single digit °F, but there tend to be 30°F swings per day (dry, high desert). Freezing hasn't been an issue as it's rarely below freezing for more than a few days at a time.

Firing up and running that pump every time two houses need water is going to be brutal to your power system.

He had a 10S??? pump @ 700' depth that burned 18-19A single phase 230VAC. It was only pumping about 7gpm. He swapped it out for a 5S20-39 that only consumes 2400W and pumps about 4.5gpm.

 

[robby]

My neighbor uses that config. He runs 2 hours per week to top off his 2X 1000gal cisterns with the dedicated inverter. A pressure tank and 1/2hp jet pump running off the lower power Magnum (powers the whole house, very low idle consumption) that feeds the house

Every time I see a Well pump question I keep wondering why more people do not pump the water into a thousand gallon tank with a LF Inverter and then use an HF Inverter to power their home. Seems to me like the amount of power saved is worth having two separate Inverters.