WELL PUMP and Inverter QUESTION

Oscar13601 · June 2012

Is time for me to buy a well pump (Well is 163 feet deep, and I need sufficient water for a small house and a small cabin, also a 120 press tank). I see that the Grundfos pumps have a slower start than other pumps in the market. What pump will you guys recomend, or which one? Also, I want to buy what will last and what will work. I see here in the forum that the best results are given by the 240V pumps for their lower amperage. Now, is it better to use a autotransformer or to use 2 inverters, or should I think on buying a 240V inverter (like the Xantrex). Another question is: Can I use the Outback charge with a Xantrex Inverter? I mean, can I use all the features on both eventhogh they are not made by the same manufacturer.

I'm buying the system slowly as is too costly. But, I want to get the best!!! I'm thinking about:
6 PV 230W
Outback charge controller 80A
Xantrex 120/220V 4500W
4 Batteries Initially, then 8 (24V system)

vtmaps · June 2012

Re: WELL PUMP and Inverter QUESETION

You can certainly mix components from different manufacturers, but you will not be able to take full advantage of all integration features. Many of these features are theoretically nice but not very important.

As far as the pump goes, you can certainly use a transformer. You can also use a 115 volt pump, but they tend to have lower gpm (or they would draw too many amps for 115 volt wiring). At my former abode I used a 115 volt submersible pump and found it quite adequate for a small house. If you want to have three showers running at once you will need either the greater gpm of a 230 volt pump or an extra large pressure tank with the 115 volt pump.

--vtMaps

mikeo · June 2012

Re: WELL PUMP and Inverter QUESETION

Well is 163 feet deep, and I need sufficient water for a small house and a small cabin,

I have installed a system for a neighbor and we use an old Xantrex sw5548 inverter and newer XW-150 charge controller with auto-transformer and it has performed well. With the well depth and depending on the distance from your inverter, I think 240 volts would be your best bet. An auto-transformer is a lot cheaper than buying a second inverter unless you have other circumstances that require more power then a single inverter can provide. You are looking at about 35 amps starting surge and 6 amps running draw so wiring and breakers should be sized appropriately. Double these currents for a 120 volt 1/2 HP pump.

stephendv · June 2012

Re: WELL PUMP and Inverter QUESETION

You can also use a VFD (Variable Frequency Drive) to convert single phase to 3 phase and do the transformation from115 to 230V. This lets you use slightly cheaper 230V 3-phase pumps which should be more reliable than single phase and you get to start them up very softly through the VFD. In fact you have complete control of the pump so you can choose to run it at any speed.
It's a bit more of a fiddly solution as most VFD's were just designed to run 3 phase motors not specifically pumps, so if you wanted low-water cut-off you'll have to bodge your own solution together.
The grundfos SQ series is simpler and if you can get away with 110V, I'd be tempted to just go that route.

EDIT: Link to some 110 to 230V VFDs: http://www.dealerselectric.com/mfg-subcat-item.asp?cID=28&scID=164&mID=-1

mike95490 · June 2012

Re: WELL PUMP and Inverter QUESETION

Is time for me to buy a well pump (Well is 163 feet deep, and I need sufficient water for a small house and a small cabin, also a 120 press tank).

So, you have to caculate for 150' lift ( never place a pump at the very bottom ) and add whatever pressure your tank is going to run - say 40 psi ?
http://www.engineeringtoolbox.com/pump-head-pressure-d_663.html
So you need generate about 110 psi at the bottom of the well, or about 250' of lift.

Then you need to look at pump curves, and find a set of rotors that will produce efficently at that pressure. Then you size the motor for the volume you want, say 2gpm, and with a large pressure tank, you should be able to fill a load of wash with the 60 gallons in the tank (half water, half air)

http://www.grundfos.com/service-support/encyclopedia-search/performance-curve.html
curves for 1 line, are on page 8 : http://net.grundfos.com/Appl/WebCAPS/Grundfosliterature-743128.pdf

I use a Contactor wired to my switch, so the switch does not carry the whole current. Easy to repair/replace contacotrs.

And 3 wire pumps are supposed to start easier off grid, than 2 wire pumps.

for your well cable, use #10 or better wire

Mike

Ken Marsh · July 2012

Re: WELL PUMP and Inverter QUESETION

A comment on Stephendv's post:
The small low cost VFDs we get in America do not have a transformer hence are not able to shift voltage.
Some of the older VFDs did incorporate transformers but they were very expensive
and are not what we are getting now.

Generally speaking three phase motors are 220/440 volt
So this means wire the motor for 220, use a 220 VFD and power it with 220 volt single phase.
But submerged pump motors do not give you the option of changing voltage.

Half Hp submerged single phase pumps start well with inverters 4 Kw and up.
Anything larger in Hp, better go 3p or Grundfos route.

stephendv · July 2012

Re: WELL PUMP and Inverter QUESETION

Ken Marsh wrote: »

A comment on Stephendv's post:
The small low cost VFDs we get in America do not have a transformer hence are not able to shift voltage.
Some of the older VFDs did incorporate transformers but they were very expensive
and are not what we are getting now.

Hi Ken, the VFD's in the link I posted above are from an american site and seem to be about $100 for 1/2HP.

Ralph Day · July 2012

Re: WELL PUMP and Inverter QUESETION

If you want to keep it simple a Grundfos can't be beat. I replaced a 240v pump/autotransformer setup with a 120v Grundfos. The start surge on the 240v pump would make the colour tv black and white and the picture 15% smaller for a second or so. The Xantrex inverter status screen would register 42 or more amps (35 amp breaker). The Grundfos soft starts so you don't even know it's running except for the little led status light (oven neon pilot light) wired into the circuit. My neighbour has a Grundfos pump that's been in the well for 25 years without any problem or service needed.

I do provide my minisplit heat pump 240vac supply from the resurrected Xantrex T240 autotransformer. As an aside, yesterday with temps in the 90's the house stayed at 72F all day, the heat pump ran for 11 hours+ and consumed 2.11kwhrs of electricity (all solar and wind provided). Inverter controlled mini splits are wonderful.

Ralph

Oscar13601 · July 2012

Re: WELL PUMP and Inverter QUESTION

Ok, so you guys think that I should go with the 220V pump? If I do go that route, then I will probably get the Xantrex or the Magnum 4000 W 120/220V inverter (what you guys think)? Is this type of inverter have 2 diffent outputs? Like 1 for the well pump (220V) and the other 120V for the house. Now, or is it better with a straight 120V inverter and an autotransformer? This is for a vacation home, and I'm building the system slowly, but I want what works. I also learned in this forum that the 120V pumps have a HIGHER amperage than the 220V...

Thanks Guys

BB. · July 2012

Re: WELL PUMP and Inverter QUESTION

Power = Voltage * Current ... So if you double the voltage (120 to 240 VAC), then the current will be 1/2 for the same amount of power.

Transformers cost power (~5% or so), and if you cannot turn the transformer off with the local pressure switch, there is power draw 24x7 (if there is a long wire run from the inverter to the well head, it becomes more of a pain to remote switch the transformer with the well pump switch--unless the pressure switch is near the shed).

The Grundfos SQ Flex series is nice... it can take a wide range of AC or DC power (even direct solar panels without batteries). But it is not cheap.

-Bill

mike95490 · July 2012

Re: WELL PUMP and Inverter QUESTION

BB. wrote: »

Power = Voltage * Current ... So if you double the voltage (120 to 240 VAC), then the current will be 1/2 for the same amount of power.

Transformers cost power (~5% or so), and if you cannot turn the transformer off with the local pressure switch, there is power draw 24x7 (if there is a long wire run from the inverter to the well head, it becomes more of a pain to remote switch the transformer with the well pump switch--unless the pressure switch is near the shed).

The Grundfos SQ Flex series is nice... it can take a wide range of AC or DC power (even direct solar panels without batteries). But it is not cheap.

-Bill

Water pumping was a MAJOR factor for my selecting a 240V pump and inverter. And the cost of "soft start" pump vs an "ordinary" pump. I can afford to buy a spare pump, and have it on hand (I've got about 9,000 of elevated storage) and take a day or 3 to replace one, but if I had to wait 2 weeks to get the fancy pump shipped, and then another 2 weeks 'cause its controller died (I'm still not sure if you need the $400 controller, or just the pump and it's built in electronics/MPPT). I've lost some efficiency, but I feel I've gained reliability.
I ran an additional control line 600' from my tanks, to the pump station, to control the pump Contactor Relay, I doubt it would have worked without a control relay for the contactor, that was a 1200' run up and back from the float switch. Photo album

If I was going to do it over, I would get a 3 phase motor, and soft start it from a VFD. I've not heard of many problems with them (maybe because not many people are using them?) But then I'd have more wires going down the well to the motor. Lots of trade-offs to think about.

And when you size a transformer for your pump (step-up 120 - 240), make sure the transformer is rated for the starting surge, or it WILL NOT be able to start the pump. Overloaded transformers loose output on the first cycle, you cannot "force" any extra power through the core.

Ken Marsh · July 2012

Re: WELL PUMP and Inverter QUESTION

Stevendv,
Very interesting and thanks for the link. I was not aware that they made boost versions.
All the VFDs I have gotten for home shop use are 2 Hp and up and they all have bridge type chopper output.
They can not convert the voltage.
But see from your link that there are boost versions available in 1/8 to one Hp.
And they are Teco too. That is my favorite brand.

For general interest,
With standard motors, the Tecos work right out of the box.
The instructions they send with them are straight ahead and easily understood.
They come set for 60 cycle motors.
For most applications the only thing you have to program is how you control them,
ie use the push buttons on the front or external contact closure or external pot, etc.

Got into a real hassle last week with a 4 Hp Huanyang.
Purchased it through ebay directly from China at a ridiculously low price.
Nothing worked out of the box.
It was necessary to reprogram the whole unit.
The instructions they sent are English but evidently word for word translation from the Chinese.
Their terminology is unknown to me and notation inconsistent.
It took most of the day to figure this out and a couple of times I just about threw the whole thing in the trash bin.
But we preserved and it came out good. The units work.
Actually I purchased three of them, one is defective.
The push buttons do not make good contact and you have to use them to get the unit programmed.
But again we preserved and managed to get it going.
I will use it in an application with external controls.
I have applied 6 or 8 Tecos all of which worked great from the start.

The 4 Hp Huanyang VFD is going on a 3 1/2 Hp water sourced heat pump (hopefully so that is).
This heat pump is the reason we are not off grid.
It provides a comfort and convenience level that would make me very unpopular if I were to shut it down.
It also has a 200 amp starting inrush which makes it unpopular with any inverter.

PhilS · July 2012

Re: WELL PUMP and Inverter QUESTION

I went with a Grundfos pump a couple of years ago and am VERY happy with it. It runs from an old Xantrex SW2512MC inverter, and there's a jet pump that also is powered from that same inverter. I can have the Grundfos pump running and if the jet pump kicks on, no problem. The pump is down the well about 350'.

I still find it almost "magic" that you can give that Grundfos either AC or DC, and any voltage from 30V to 250V, and it'll work. I do use the CU200 controller.

Phil

mike95490 · July 2012

Re: WELL PUMP and Inverter QUESTION

Just a clarification here - Grundfos makes MANY pumps, but only the SQ Flex series, has "down the well" electronics for any sort of power. And you pay dearly. And they are very efficient.

The other series all use AC line power motors.

Texas Wellman · July 2012

Re: WELL PUMP and Inverter QUESTION

The SQ Flex can be had for about $2000 and is plug and play. Is that "pay dearly"?

Texas Wellman · July 2012

Re: WELL PUMP and Inverter QUESTION

I would like to know more about your set-up. Are there batteries involved for the solar to A/C pump?

PhilS wrote: »

I went with a Grundfos pump a couple of years ago and am VERY happy with it. It runs from an old Xantrex SW2512MC inverter, and there's a jet pump that also is powered from that same inverter. I can have the Grundfos pump running and if the jet pump kicks on, no problem. The pump is down the well about 350'.

I still find it almost "magic" that you can give that Grundfos either AC or DC, and any voltage from 30V to 250V, and it'll work. I do use the CU200 controller.

Phil

stephendv · July 2012

Re: WELL PUMP and Inverter QUESTION

Texas Wellman wrote: »

The SQ Flex can be had for about $2000 and is plug and play. Is that "pay dearly"?

Yes it is

From a quick google search comparing a 1.4kW SQFlex pump for around $2000, to a 1.5kW Franklin 3 phase pump ($650) + VFD that converts 115V single to 230V 3 phase ($350)- you have a modular industrial quality system for half the price.
It's not an entirely fair comparison because the SQFlex has a built in MPPT controller and can operate on a much wider voltage range. But for installations that already have a inverter I think it's cheaper and a more repairable route to go 3 phase + VFD.

PhilS · July 2012

Re: WELL PUMP and Inverter QUESTION

Texas Wellman wrote: »

I would like to know more about your set-up. Are there batteries involved for the solar to A/C pump?

I may be misunderstanding your question.

I have a battery bank that feeds three inverters, two for the house (appliances and electronics) and one for water (submersible well into a cistern, jet pump to a couple of bladder tanks for pressure to the house).

Solar panels charge the battery bank most of the time, a generator does that when there's no sun.

Phil

mike95490 · July 2012

Re: WELL PUMP and Inverter QUESTION

Texas Wellman wrote: »

I would like to know more about your set-up. Are there batteries involved for the solar to A/C pump?

Yes. batteries are needed to stabilize the solar power, to run an AC pump. The SQ Flex pump does not need batteries, it can run right off the solar panels.

Dave Angelini · July 2012

Re: WELL PUMP and Inverter QUESTION

stephendv wrote: »

Yes it is
From a quick google search comparing a 1.4kW SQFlex pump for around $2000, to a 1.5kW Franklin 3 phase pump ($650) + VFD that converts 115V single to 230V 3 phase ($350)- you have a modular industrial quality system for half the price.
It's not an entirely fair comparison because the SQFlex has a built in MPPT controller and can operate on a much wider voltage range. But for installations that already have a inverter I think it's cheaper and a more repairable route to go 3 phase + VFD.

Any model numbers of VFD controllers and their availability/longevity for Offgrid? I know I keep asking this question...Cost means very little when the water stops flowing!

stephendv · July 2012

Re: WELL PUMP and Inverter QUESTION

Dave Sparks wrote: »

Any model numbers of VFD controllers and their availability/longevity for Offgrid? I know I keep asking this question...Cost means very little when the water stops flowing!

If reliability is a concern then I would pick well known brands: Hitachi, Baldor, etc there is a very wide range available. I bought a cheap chinese version because I'm cheap

and it's easily replaceable. Can't really comment on longevity as it's only been running 1 hour per day for 3 years. A VFD is essentially an MSW inverter, so I would expect it to match those for reliability.
The one thing which put me off the grundfos SQFlex is that all the electrics are in the pump- and I didn't fancy pulling up 400ft worth of pipe + pump to troubleshoot electronic problems!

Dave Angelini · July 2012

Re: WELL PUMP and Inverter QUESTION

Ok I see your point. I do have really good experience with Grundfos over the decades and I am always concerned with electronics (controllers) being in remote sites. I do like the brute force 240 vac pumps as the electronics or a generator is always easy to sub out.

With the VFD one would have to have spare controller and would give up the ability to pump from a commonly available generator. If Wind and Sun had the controllers available or someone like them I might see your advice as reasonable. Cost just really does not mean much when the water stops flowing in most of my applications.

Ken Marsh · July 2012

Re: WELL PUMP and Inverter QUESTION

"With the VFD one would have to have spare controller and would give up the ability to pump from a commonly available generator."

Dave, The VFD run pumps will operate from any source of power, generator included, as long as the voltage is correct.
Maybe you mean that you can not run the pump directly without the VFD??
If you have a 3P generator you can run them direct.
I don't know abt the Grunfos SQ's.
And yes, It would be a good idea to have a spare VFD if the water supply is essential.

Dave Angelini · July 2012

Re: WELL PUMP and Inverter QUESTION

Exactly Ken! You cannot run the pump unless you have a 3-phase generator or another VFD controller. You probably would need 2 spare controllers and even then I would not feel it is worth it unless this strtegy became common, which it is not in my opinion.

Texas Wellman · July 2012

Re: WELL PUMP and Inverter QUESTION

Thanks for the info. I was hoping there was a way to go straight from the panels to the inverter to the pump, and skip the batteries.

inetdog · July 2012

Re: WELL PUMP and Inverter QUESTION

Texas Wellman wrote: »

Thanks for the info. I was hoping there was a way to go straight from the panels to the inverter to the pump, and skip the batteries.

If you want to skip the batteries, you will have to skip the inverter also and go directly from panels to Grundfos pump at the bottom of the well! Is that alternative looking any better to you as you the alternatives diminish?

WELL PUMP and Inverter QUESTION

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