I need to power a 240 V well pump in an off grid location

[murdsman]

At the source of the power for the well pump I would like to have 120 v available also.
What is the best way or ways I can achieve this. I have looked at inverters that put out 240v and converting to 120v or starting with 120v inverters and converting to 240v.
The well pump runs at 8 A with a start up at 13 A
Thoughts and suggestions are appreciated
Thanks

 

[harvardbeans]

I bought a split phase inverter for the same purpose and it works well. It has one 240v universal outlet and four 120v outlets.

$600 on Amazon

Edit = for $30 more there is a 3500W 14.5A version

 

[sunshine_eggo]

At the source of the power for the well pump I would like to have 120 v available also.
What is the best way or ways I can achieve this. I have looked at inverters that put out 240v and converting to 120v or starting with 120v inverters and converting to 240v.
The well pump runs at 8 A with a start up at 13 A
Thoughts and suggestions are appreciated
Thanks

A split phase inverter is likely the best bet to get 120/240VAC.

Are you 100% certain the startup is only 13A? Most pumps/big motors are about 5X run, so I would expect 40A surge at startup. If you measured this with a AC clamp ammeter with an INRUSH function, it might be real, or if it's published.

This monstrosity will absolutely handle it. It's cheap, BUT it's HEAVY, and it has a high idle current load:

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I bought a split phase inverter for the same purpose and it works well. It has one 240v universal outlet and four 120v outlets.

$600 on Amazon

While I like that brand and have a 2000W/24V inverter from them - no way that unit has a legit surge. At 18# weight, it doesn't have a beefy transformer, and it would overload at pump startup. I have a 3/4hp high efficiency jet pump that only pulls about 800W (6.7A @ 120V). My WZRELB 2000W/4000W surge inverter couldn't handle it.

 

[Oldphile]

I agree, typical start current is 5X.

 

[harvardbeans]

A split phase inverter is likely the best bet to get 120/240VAC.

Are you 100% certain the startup is only 13A? Most pumps/big motors are about 5X run, so I would expect 40A surge at startup. If you measured this with a AC clamp ammeter with an INRUSH function, it might be real, or if it's published.

This monstrosity will absolutely handle it. It's cheap, BUT it's HEAVY, and it has a high idle current load:

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While I like that brand and have a 2000W/24V inverter from them - no way that unit has a legit surge. At 18# weight, it doesn't have a beefy transformer, and it would overload at pump startup. I have a 3/4hp high efficiency jet pump that only pulls about 800W (6.7A @ 120V). My WZRELB 2000W/4000W surge inverter couldn't handle it.

I ran a test and it handled the pump just fine for a week straight

 

[sunshine_eggo]

I ran a test and it handled the pump just fine for a week straight

You have the same pump?

 

[harvardbeans]

My pump should have pulled 15A at start up. The inverter says its max amperage output is 12.5. it has a soft start design and according to the digital screen when the pump is on, it's constantly using 12.2 amps with no surge. I need to put an amp clamp on it while it's connected to AC and see what the surge/running amps would normally be.

 

[Ampster]

@harvardbeans , I assume you are talking about the soft start in the pump or do you have a separate soft start device?
A soft start pump is an entirely different scenario than the OP unless he can verify that he has a soft start pump as well?

 

[sunshine_eggo]

My pump should have pulled 15A at start up. The inverter says its max amperage output is 12.5.

Unlikely that your inverter is sampling/reporting data fast enough to truly capture the peak.

it has a soft start design

This is why your inverter handles it. A soft start design explicitly reduces the surge by as much as 70%. I guarantee that your inverter would not start the same pump without a soft start mechanism.

The OP has given us no hard data and the data given is questionable. I'm not going to recommend something that carries high risk of failure for a typical installations (soft starts are pretty rare).

 

[MichaelK]

Here is a pump chart that I referred to many times before. I've found it to be very accurate, based on real-world readings I've made on pumps myself.


I suspect you are measuring the startup surge incorrectly? Are you using a plain AC clamp meter? They are too slow to capture the true surge, which takes place in less than 500 miliseconds or so. You need a clamp meter with in-rush current capability for that. I use a Uni-T-216C.

Now my pump pulls about 9100W right at startup. It's 240VAC 1hp Grunfos. I don't think that inverter mentioned can handle an in-rush that high. It appears to be able to go only up to 6000W, and the amount of time it can surge that high is NOT documented, so I'd expect it's not very long. My rule of thumb is that a quality inverter company will tell you how long the inverter can surge. The cheap quality companies only tell you how high it can surge. That makes a BIG difference. BTW, my Schneider XW6848 has powered my pump flawlessly for 6 years now. It is a serious, low-frequency transformer-based inverter. It can surge to 200% for 60 seconds.

 

[harvardbeans]

Unlikely that your inverter is sampling/reporting data fast enough to truly capture the peak.



This is why your inverter handles it. A soft start design explicitly reduces the surge by as much as 70%. I guarantee that your inverter would not start the same pump without a soft start mechanism.

The inverter has a soft start design

From the inverter's Amazon "About this item" description

• 【Soft Starter Design】 with soft starter built in, reduces the instantaneous impact of inrush current to allow the AC voltage to rise smoothly, effectively extending the life of the appliance

 

[murdsman]

Thanks for the input, I got the 13A from the panel data sheet. I will be going up to the site next week and I will measure it. I have a gas powered generator that I use to run the pump now.

 

[Ampster]

I got the 13A from the panel data sheet.

Panel data sheet? The one on the pump?

 

[harvardbeans]

@harvardbeans , I assume you are talking about the soft start in the pump or do you have a separate soft start device?
A soft start pump is an entirely different scenario than the OP unless he can verify that he has a soft start pump as well?

The inverter claims to have a soft start design. I assumed that was how it could run my stp since the surge should have been more than 12.5A. I will measure the surge this week while it's on AC and see if it is in fact higher and the inverter was able to reduce the surge.