Old 4" submersible died, need advice on new pump

BenA

Hi All,

The old 4" is history and we are looking for a replacement.  Well is 270' deep and submersible is at 100 feet.  Need 5 or more gallons per minute.  The well head has 220V available (PV, pure-sine wave) so we need a pump that's frugal on power and hopefully low starting current.  Must be reliable.  Would really like to use a standard well pump control and pressure tank (without a bunch of specialized control modules).

I thought I had found perfection with the Grundfos SQF pump but it appears to require separate controllers and such.  What would you be using if you were in this situation?  Sure would appreciate your input!

mike95490

I decided to use regular well pump, and a beefy inverter to start it up,
 my setup is in my .sig.
But my pump may not work for you, you need to go to a pump store with big fat paper catalogs and look at the pump curves, that's how you find a pump for your lift/psi and volume requirements.
3 wire control pumps have a easier starting surge than 2 wire pumps

mike95490

BB.

Use a smaller pump to cistern (many hours of sun, possible direct from solar panels and no batteries to fill tank)? Then use small (or larger) surface pump for pressure to house/irrigation?

-Bill

Dave Angelini

The no-brainer solution is a type SQ from Grundfos.  You are welcome to contact me if you need specifics!

Anawa

I'm with Angelini. 

BenA

Dave Angelini said:

The no-brainer solution is a type SQ from Grundfos.  You are welcome to contact me if you need specifics!

I wish I had seen this post earlier.  I would have steered the order to you (forum supporter).  An SQ series and accessories was ordered from the internet several days back ....

BenA

mike95490 said:

I decided to use regular well pump, and a beefy inverter to start it up,

The current setup is a 4kw Magnum inverter that powers a Sta-rite 1 hp 2 stage pump.  The analog AC wattmeters are pegging at pump startup and the Four Star Solar Magnum MS4024PAE panel is throwing fault conditions at startup.

We are hopeful that the Grundfos SQ, soft-start submersible is the answer to knock down this very-high load.

Dave Angelini

Don't be hopeful, The SQ will soft start and all will be well, a pun was intended. The load will still be there though!

Solar2

I do not use the SQFs anymore.
True they are top quality.

But when you are looking for top efficiency, they mostly work off peak efficiency.
You end up using double (or more) the power to pump your water.

I'm with Mike.
I like it to pump up with the pump operating at max efficiency then shut off.

There is one more thing you can do for limited solar.
You can run it with a VFD, have no starting surge and get even higher efficiency.
The pump motor must be three phase and used three phase motors are getting hard to find.
But even with buying a new motor the parts are 1/3 the $.

As soon as the sun comes up I am going over to the kids place and change out his pump motor.
They are off grid with a nice little diesel generator which charges the batts using the inverter charger.
The problem is when they are charging at a decent rate the well will come on and the starting surge knocks the genset off line.
The genset has to then be manually reset.
The local well driller had a NOS 3 phase motor in stock he didn't know what to do with and gave us a great price.
He still thinks we don't know what we are doing and it will not work!

jonr

The Pentek Intellidrive will add VFD to a non 3-phase pump.  It would be interesting to see actual measurements for its startup power draw.

mike95490

I use a 6KW inverter to start a 1/2 hp pump motor. no worries .

Solar2

jonr said:

The Pentek Intellidrive will add VFD to a non 3-phase pump.  It would be interesting to see actual measurements for its startup power draw.

There are many manufactures jumping in now.

Franklin has three series of VFD type drives that use electronic drives for standard polyphase motors.
   SubDrive = two phase series for regular three wire motors.
   MonoDrive = series for standard three phase motors to be used in line connected installations.
   PHOTON = series for solar installations using standard three phase motors.

Note they all use standard motors that have been around for 60 years.

As for how much current they draw on start up:
Practically nothing, the motor will start to turn with a clamp type ammeter not showing any current.
Current then ramps up in direct proportion to rpm, reaching full current when the motor reaches full rpm.
Conventional VFDs will let you set the start up and decelerate ramp time.

Dave Angelini

You left out the gold standard Grundfos. Nothing conventional in their SQ and SQF series and nothing new. Been around for decades with the first VFD built-into the pump. A fine Danish company started just after WW2. There is a plant down in Clovis CA. and I always see their cut-away displays in the airport at Fresno.

jonr

Trying to put some rough prices on these things.   3 phase motor/pump + ebay generic VFD is maybe $500 plus $150.    Grundfos SQ is maybe $750.

VFDs for single phase motors are about $1000 just for the VFD (you still need the motor/pump).

Solar pumps, perhaps $2000 (http://www.solar-electric.com/).

Solar2

mike95490 said:

I use a 6KW inverter to start a 1/2 hp pump motor. no worries .

Right.  Most of our wells are 1/2 Hp too.
But even a 1/2 Hp single phase pump will draw enough start up current to kick out the genset
when it is al-ready charging the battery at near max amps.

Our two main gensets are propane fueled.
This is because of the convenience of propane.
But propane is not very efficient at low load.
You do not want to have your propane fueled genset running at low output.
So we crank up the charging current.
This makes them susceptible to surges.

Do you charge your battery direct or through the inverter?

I have the components for a 175 amp charger setting in my shop.
But that is another project.

mike95490

I have solar to charge the battery, and if it's cloudy, I use the 240V generator input to the Inverter and use it's internal charger to get 60V @ 40A into the batteries.  I have a small stand alone 15A charger runs off 120VAC.

BenA

We got the Grundfos 10SQ05-160 pump installed and it's completely amazing.  Zero voltage spike on start and the watt meters on L1 and L2 slowly rise to 500 watts each.

The pump was installed at 160 foot and the flow of water is unmeasured so far but its a very strong stream.  The 15 year-old pump that came out of the well was a Grundfos also.  Amazing.

Dave Angelini

Yes they are amazing! We have one that is about 18 years now.
 I keep waiting for them to price a similar surface pump 1/2 HP with soft start. Because of the cooling they really get expensive when they are not sitting in water.

BenA

Dave Angelini said:

Yes they are amazing! We have one that is about 18 years now.
 I keep waiting for them to price a similar surface pump 1/2 HP with soft start. Because of the cooling they really get expensive when they are not sitting in water.

I'll be the first one in line to buy one  

Dave Angelini

Me too!  
I have a Goulds Irrigator 1HP pump that I use as a Fire pump to hose down the area if we get a wildfire. I would not run my computer/HE washing machine when the pressure switch turns that pump on. Yeow!
 It will shoot a 1.5" stream of water 50 feet in the air though.