Problems with Deep Well Pump and Low Frequency Inverter

[1unluckyguy]

Long time fan. However I've recently come into a problem that is driving me to my wits end. I will give all relevant specs I can think of ahead of time, as to encourage support:

Inverters Tested:
Sun Gold Power 6KW 48v Low Frequency Split Phase (120v/240v) Inverter
2 different Sun Gold Power 4KW 24v Low Frequency Split Phase (120v/240v) Inverter
Battery Bank:
4 Group 921 Super Start Batteries (O'Reilly's Auto) deep cycle lead acid batteries, 2s2p for 24v and 4s1p for 48v operation
Well Pump in Question:
Zoeller Model 1463-0006 Convertible Jet Pump The pump was correctly wired at both the windings, and at the pressure switch for 240v input. Pump was installed as a deep well jet pump.
Video Evidence:
Error Video 1 - Error Video 2

As the videos above show, there is a constant, restarting, surging any time the pump is running on inverter power. The pump would work when connected to line power. I initially thought the problem was with the first 24v inverter, so I got a second 24v inverter and it displayed the same behavior. The videos show the third attempt using a 48v 6KW version. The reason for the third attempt is that no matter what, using a amperage tester on the ac side would have a max draw of 20 amps AC on the 4KW 24v inverters, so I assumed that 6KW version would allow it to actually run. Even with the larger inverter, it just registered 24 amps of AC draw while exhibiting the same behavior shown in the video. Before anyone asks: The 6KW is the updated model that has removable ground/neutral bond. Testing with and without this bond yielded the same results.

This has lead me to believe that the well pump is the problem, even though I don't know how or why its happening. The most heartbreaking part of this ordeal is that I researched online as to the feasibility of running a well pump online, which is why I wanted to be able to use water when the very occasional power outage happens due to strong storms and hurricanes. There are countless videos online of guys wiring up even high frequency 120v inverters with golf cart batteries to work with similar deep well pumps successfully, yet all my investment doesn't yield fruit.

Unfortunately, it seems that the pump has subsequently died due to age and what I can only assume was accelerated wear due to attempting to troubleshoot this problem. I would like to know if anyone else had a similar experience and found a solution, or recommend me things to try before I even bother purchasing another well pump only to have the same problem. I will be able to rest if I can find a solution for anyone in the future, as I have spent 6 weeks testing and researching, only to find that this problem seems to be unique to me, as there is nothing about this problem anywhere on the neutered internet we have now. Please help me.

 

[OzSolar]

Sorry about your issues and welcome to the forum.

Did you happen to measure the amps the pump needed to start when it was connected to the grid?

Over the years I've had few customers with surface jet pumps and I was amazed by how nasty hard they were start. It's been a while so I don't recall the specifics now but dang... every time the pump started I was holding my breath. The inverter groaned and moaned like it was going to die but it did start and run it. We switched to Grundfos SQ and the inverter was so much happier.

Maybe it's time for a SQ?

 

[GRMRC]

Long time fan. However I've recently come into a problem that is driving me to my wits end. I will give all relevant specs I can think of ahead of time, as to encourage support:

Inverters Tested:
Sun Gold Power 6KW 48v Low Frequency Split Phase (120v/240v) Inverter
2 different Sun Gold Power 4KW 24v Low Frequency Split Phase (120v/240v) Inverter
Battery Bank:
4 Group 921 Super Start Batteries (O'Reilly's Auto) deep cycle lead acid batteries, 2s2p for 24v and 4s1p for 48v operation
Well Pump in Question:
Zoeller Model 1463-0006 Convertible Jet Pump The pump was correctly wired at both the windings, and at the pressure switch for 240v input. Pump was installed as a deep well jet pump.
Video Evidence:
Error Video 1 - Error Video 2

As the videos above show, there is a constant, restarting, surging any time the pump is running on inverter power. The pump would work when connected to line power. I initially thought the problem was with the first 24v inverter, so I got a second 24v inverter and it displayed the same behavior. The videos show the third attempt using a 48v 6KW version. The reason for the third attempt is that no matter what, using a amperage tester on the ac side would have a max draw of 20 amps AC on the 4KW 24v inverters, so I assumed that 6KW version would allow it to actually run. Even with the larger inverter, it just registered 24 amps of AC draw while exhibiting the same behavior shown in the video. Before anyone asks: The 6KW is the updated model that has removable ground/neutral bond. Testing with and without this bond yielded the same results.

This has lead me to believe that the well pump is the problem, even though I don't know how or why its happening. The most heartbreaking part of this ordeal is that I researched online as to the feasibility of running a well pump online, which is why I wanted to be able to use water when the very occasional power outage happens due to strong storms and hurricanes. There are countless videos online of guys wiring up even high frequency 120v inverters with golf cart batteries to work with similar deep well pumps successfully, yet all my investment doesn't yield fruit.

Unfortunately, it seems that the pump has subsequently died due to age and what I can only assume was accelerated wear due to attempting to troubleshoot this problem. I would like to know if anyone else had a similar experience and found a solution, or recommend me things to try before I even bother purchasing another well pump only to have the same problem. I will be able to rest if I can find a solution for anyone in the future, as I have spent 6 weeks testing and researching, only to find that this problem seems to be unique to me, as there is nothing about this problem anywhere on the neutered internet we have now. Please help me.

What do you consider “deep well”? I am 540ft down the hole and my well pump is at the bottom. 1.5hp, 240v. No problem running it.

 

[1unluckyguy]

Sorry about your issues and welcome to the forum.

Did you happen to measure the amps the pump needed to start when it was connected to the grid?

Over the years I've had few customers with surface jet pumps and I was amazed by how nasty hard they were start. It's been a while so I don't recall the specifics now but dang... every time the pump started I was holding my breath. The inverter groaned and moaned like it was going to die but it did start and run it. We switched to Grundfos SQ and the inverter was so much happier.

Maybe it's time for a SQ?

I appreciate your sympathy.
>Did you happen to measure the amps the pump needed to start when it was connected to the grid?
Yeah, it was about 26 amps of AC current, which theoretically even the 4KW LF inverter has the surge capacity to start. Which makes this situation even more bizarre.
>Grundfos SQ
I've heard of them and they seem to just be submersible types. My well system, as shown, is a surface installed deep well system requiring an intake, pressure and outlet lines. The CM series seems to be closer to what I need, but I only see two lines on those.

What do you consider “deep well”? I am 540ft down the hole and my well pump is at the bottom. 1.5hp, 240v. No problem running it.

To be honest I didn't install the well system. It a legacy system that was reactivated because of a family farm running the primary well dry with livestock. Logically it has to be deeper than 25ft to require the configuration, but it can't be that deep as its gone dry on us before during the drier months of the year and its a modest house of 1100 sqft.

Any help would be appreciated. I want to just install a new Zoeller pump to see if it was truly the problem, but I would hate to do so, only to be back to where I started.

 

[GRMRC]

I appreciate your sympathy.
>Did you happen to measure the amps the pump needed to start when it was connected to the grid?
Yeah, it was about 26 amps of AC current, which theoretically even the 4KW LF inverter has the surge capacity to start. Which makes this situation even more bizarre.
>Grundfos SQ
I've heard of them and they seem to just be submersible types. My well system, as shown, is a surface installed deep well system requiring an intake, pressure and outlet lines. The CM series seems to be closer to what I need, but I only see two lines on those.

To be honest I didn't install the well system. It a legacy system that was reactivated because of a family farm running the primary well dry with livestock. Logically it has to be deeper than 25ft to require the configuration, but it can't be that deep as its gone dry on us before during the drier months of the year and its a modest house of 1100 sqft.

Any help would be appreciated. I want to just install a new Zoeller pump to see if it was truly the problem, but I would hate to do so, only to be back to where I started.

Livestock around and that shallow of a well, make sure you get the water tested for contaminants. Don’t be drinking that water blind.

 

[MakeMePower]

jet pumps are not deep wells, there is a limit to how far they pump, roughly 120 feet is the max depth. be aware if you don't have a inrush meter, you are likely not seeing the true surge. jet pumps typically don't have large requirements. you can install a soft start, but feel something else is occuring.

 

[HarryN]

Just as a way to reduce the chance that the batteries are struggling, is there a way use one of the inverters to feed extra charging power into the setup for the pump ?

For instance a battery charger ?

Perhaps check and see if the individual batteries are all at the same voltage ( when not under load ). Should be within 0.1 volts of each other normally, or close.

Another possibility since the pump died is that the motor was sensitive to the sine wave quality. If the inverter under load starts to shift toward being a lower quality waveform, this can damage older motors that are not designed for it.

Just throwing out some ideas.

 

[42OhmsPA]

I'm leaning towards not enough battery / undersized cable.
When I was running my TP6048 I had no issues starting my 1HP deep well I clamped ~40A per leg inrush on the AC side.

 

[42OhmsPA]

Those batteries look like they should definitely handle it.

Are you certain the pump is wired correctly? Can it be wired for 120V or 240V?

 

[1unluckyguy]

jet pumps are not deep wells, there is a limit to how far they pump, roughly 120 feet is the max depth. be aware if you don't have a inrush meter, you are likely not seeing the true surge. jet pumps typically don't have large requirements. you can install a soft start, but feel something else is occuring.

I tried one of those chinese solid state, soft start relays and it didn't help. When in "power save" mode, the soft start prevented the inverter from starting and even when fully on, the soft start would just delay the behavior in question.
>be aware if you don't have a inrush meter, you are likely not seeing the true surge.
Even the 4KW inverter is rated to 12KW surge for 20 seconds, and the 6KW has an 18KW surge. One would think 75 amps would be enough for a 1hp pump, which is why I'm thinking it was the pump starting to go bad.

Just as a way to reduce the chance that the batteries are struggling, is there a way use one of the inverters to feed extra charging power into the setup for the pump ?

For instance a battery charger ?

Perhaps check and see if the individual batteries are all at the same voltage ( when not under load ). Should be within 0.1 volts of each other normally, or close.

Just throwing out some ideas.

I appreciate it. The original setup had a battery charger attached to the 2s2p 24v setup and even then the pump exhibited the same behavior. We're talking 405 AH, so voltage drop shouldn't have been an issue.

I'm leaning towards not enough battery / undersized cable.
When I was running my TP6048 I had no issues starting my 1HP deep well I clamped ~40A per leg inrush on the AC side.

Please read the above. In the interest of fairness I am using 2 gauge cable for both the 2s2p 24v and 4s1p 48v modes. The repeated 25 amp AC draw would have corresponded to a max 100 amp draw regardless of voltage, well within the cable's spec. I believe you whole-heartedly about your set up, as there are yahoos running 1hp pumps off of even the most chinesium inverters on youtube.

Those batteries look like they should definitely handle it.

Are you certain the pump is wired correctly? Can it be wired for 120V or 240V?

Yes, if you follow the link in the OP it can be switched by rewiring the motor and pressure switch. Which I triple checked as my sanity waned.

 

[42OhmsPA]

Please read the above. In the interest of fairness I am using 2 gauge cable for both the 2s2p 24v and 4s1p 48v modes. The repeated 25 amp AC draw would have corresponded to a max 100 amp draw regardless of voltage, well within the cable's spec. I believe you whole-heartedly about your set up, as there are yahoos running 1hp pumps off of even the most chinesium inverters on youtube.

I was using 1AWG cable with 460Ah of LiFePO4. Now I'm using 2/0 with 1045Ah.
Do you have another set of cables you could parallel to rule that out?

Yes, if you follow the link in the OP it can be switched by rewiring the motor and pressure switch. Which I triple checked as my sanity waned.

So you didn't rewire anything since it's wired for 240V from the factory?

It looks like it has a 2 year warranty, any chance that's still active?


PS - Welcome to the forum.

 

[MakeMePower]

I was using 1AWG cable with 460Ah of LiFePO4. Now I'm using 2/0 with 1045Ah.
Do you have another set of cables you could parallel to rule that out?

So you didn't rewire anything since it's wired for 240V from the factory?

It looks like it has a 2 year warranty, any chance that's still active?


PS - Welcome to the forum.

shouldn't the inverters be throwing a low battery alarm if the wiring is insufficient?

 

[42OhmsPA]

shouldn't the inverters be throwing a low battery alarm if the wiring is insufficient?

That's a good question. Now that I think about it, I guess they should but don't know for sure. I suppose it depends on the low voltage setpoint.

 

[MakeMePower]

That's a good question. Now that I think about it, I guess they should but don't know for sure. I suppose it depends on the low voltage setpoint.

if the inverter can't pull the amperage needed for the load, I would expect the alarm.

 

[OzSolar]

I appreciate your sympathy.
>Did you happen to measure the amps the pump needed to start when it was connected to the grid?
Yeah, it was about 26 amps of AC current, which theoretically even the 4KW LF inverter has the surge capacity to start. Which makes this situation even more bizarre.

As has been mentioned there's some extra work that's needed when measuring well pump starting current. You need a meter that's truly capturing the inrush and know how to set it properly. (you might already know all that)

>Grundfos SQ
I've heard of them and they seem to just be submersible types. My well system, as shown, is a surface installed deep well system requiring an intake, pressure and outlet lines. The CM series seems to be closer to what I need, but I only see two lines on those.

How big is your casing? The SQ is a 3" diameter pump which I assume needs a 4" casing. FWIW: I pulled a jet pump out and replaced it with an SQ by hand with a helper.

shouldn't the inverters be throwing a low battery alarm if the wiring is insufficient?

Not necessarily from I've seen. Measuring the voltage drop across the cables or at the inverter input itself during startup would be the test.

 

[1unluckyguy]

I was using 1AWG cable with 460Ah of LiFePO4. Now I'm using 2/0 with 1045Ah.
Do you have another set of cables you could parallel to rule that out?

So you didn't rewire anything since it's wired for 240V from the factory?

It looks like it has a 2 year warranty, any chance that's still active?


PS - Welcome to the forum.

I didn't buy it, and I doubt the family member who had it installed kept the receipt. Because they aren't too reliable I'm wanting to fix this asap as I loath to be without water and the weather is already bad in my neck of the woods. Buddy I appreciate the warm welcome, but I don't want to drop another $100 in buckshot wire, on a maybe. I don't even want to spend $400 on another pump, just for it to die in a year again.

That's a good question. Now that I think about it, I guess they should but don't know for sure. I suppose it depends on the low voltage setpoint.

if the inverter can't pull the amperage needed for the load, I would expect the alarm.

Its why I upgraded to 2s2p when I started with the 24v inverter. 2s1p would cause a fault due to the draw after about 10 seconds. I was dumb enough to believe the pump's specs saying its a 1300w running draw.

These are good deductions, I'm sorry I didn't include it in my OP to save you the trouble. The brain teaser is: Why the pump would work with crappy line power but not with a cleaner pure sine wave inverter?

 

[OzSolar]

These are good deductions, I'm sorry I didn't include it in my OP to save you the trouble. The brain teaser is: Why the pump would work with crappy line power but not with a cleaner pure sine wave inverter?

I think it because it's start up surge is more than the inverter and/or batteries and/or wiring between can handle. All three of those things have to be in top shape to handle a well pump.

 

[42OhmsPA]

Buddy I appreciate the warm welcome, but I don't want to drop another $100 in buckshot wire, on a maybe. I don't even want to spend $400 in another pump, just for it to die in a year again.

Completely understand. Have a set of jumper cables you could throw on for a quick test? I know that's ghetto but what do you have to lose...

Its why I upgraded to 2s2p when I started with the 24v inverter. 2s1p would cause a fault due to the draw after about 10 seconds. I was dumb enough to believe the pump's specs saying its a 1300w running draw.

I'd guess it's closer to 2,200W.

These are good deductions, I'm sorry I didn't include it in my OP to save you the trouble. The brain teaser is: Why the pump would work with crappy line power but not with a cleaner pure sine wave inverter?

Can you still connect the grid and clamp the lines again with a meter capable of inrush?
Nothing was changed with the wiring when you switched from grid to inverter?
Do you have any other heavy draw items you could hook up the inverter to rule it out?
Water is life, I get it...

I've replayed the video about a half dozen times now, almost sounds like the pump is trying to prime.

What's the switch on the front of the inverter for?

 

[GRMRC]

I didn't buy it, and I doubt the family member who had it installed kept the receipt. Because they aren't too reliable I'm wanting to fix this asap as I loath to be without water and the weather is already bad in my neck of the woods. Buddy I appreciate the warm welcome, but I don't want to drop another $100 in buckshot wire, on a maybe. I don't even want to spend $400 on another pump, just for it to die in a year again.



Its why I upgraded to 2s2p when I started with the 24v inverter. 2s1p would cause a fault due to the draw after about 10 seconds. I was dumb enough to believe the pump's specs saying its a 1300w running draw.

These are good deductions, I'm sorry I didn't include it in my OP to save you the trouble. The brain teaser is: Why the pump would work with crappy line power but not with a cleaner pure sine wave inverter?

Have you considered the problem may be down the hole? Clogged nozzle? Busted foot valve?
If you think your inverter and wiring is fine, I would be looking down the hole.

 

[1unluckyguy]

I think it because it's start up surge is more than the inverter and/or batteries and/or wiring between can handle. All three of those things have to be in top shape to handle a well pump.

2 awg welding cable is rated for 150 amps at 105 celcius continuous. I'm using 200ah 12v deep cycle batteries and even the smaller inverter is rated for the surge draw.

Completely understand. Have a set of jumper cables you could throw on for a quick test? I know that's ghetto but what do you have to lose...

I'd guess it's closer to 2,200W.

Can you still connect the grid and clamp the lines again with a meter capable of inrush?
Nothing was changed with the wiring when you switched from grid to inverter?
Do you have any other heavy draw items you could hook up the inverter to rule it out?
Water is life, I get it...

I've replayed the video about a half dozen times now, almost sounds like the pump is trying to prime.

What's the switch on the front of the inverter for?

>Have a set of jumper cables you could throw on for a quick test? I know that's ghetto but what do you have to lose...
I do, but the pump died. I found a well (pun intended) rated replacement on amazon I'm going to try and will report back when its here and I install it.
>I'd guess it's closer to 2,200W.
Considering 1hp converts to about 750 watts, its incredible that people are allowed to marketing these pumps this way.
>Can you still connect the grid and clamp the lines again with a meter capable of inrush?
I did, it was about 20-24 amps AC and 180 amps at 24v and 80 amps at 48v.
>Nothing was changed with the wiring when you switched from grid to inverter?
No, the person who the family member used to install the pump didn't to stick to code and I almost rode lightning because of it. Hence my insistence that I double and triple checked everything. Heck the inverter has a voltage read out that's visible.
>Do you have any other heavy draw items you could hook up the inverter to rule it out?
I attached a single phase load on both phases and it worked. Subsequent to the pump burnout, it turns out that the 48v inverter suffered shipping damage so I'm looking to have it repaired.
>Water is life, I get it...
Water is love, water is life...
>I've replayed the video about a half dozen times now, almost sounds like the pump is trying to prime.
The pump, without prime, will just stay on trying to do so. But there's an interconnect between the two wells that I used to prime "my" well before testing. I should note that the pump still "worked" in this state. After hitting the pressure target it would eventually shut off. The issue apart from the repeating surge, was that even the smallest water draw would cause it to buck again. I hope this helps you endure my madness.
>What's the switch on the front of the inverter for?
Power. Up is "power save" with short pulses to detect power, to return to pulsing if the inverter becomes unloaded again. Down was for continuous power, but low frequency inverters have transformers that make them wasteful at idle.

Have you considered the problem may be down the hole? Clogged nozzle? Busted foot valve?
If you think your inverter and wiring is fine, I would be looking down the hole.

That would be worth looking into, however please remember that the pump worked with line power. The problem started when I converted to inverter power.

Gentlemen, I appreciate the help, but I'm going to buy-te the bullet on another pump and see where it takes me. I will report back on my findings.​

 

[GRMRC]

2 awg welding cable is rated for 150 amps at 105 celcius continuous. I'm using 200ah 12v deep cycle batteries and even the smaller inverter is rated for the surge draw.


>Have a set of jumper cables you could throw on for a quick test? I know that's ghetto but what do you have to lose...
I do, but the pump died. I found a well (pun intended) rated replacement on amazon I'm going to try and will report back when its here and I install it.
>I'd guess it's closer to 2,200W.
Considering 1hp converts to about 750 watts, its incredible that people are allowed to marketing these pumps this way.
>Can you still connect the grid and clamp the lines again with a meter capable of inrush?
I did, it was about 20-24 amps AC and 180 amps at 24v and 80 amps at 48v.
>Nothing was changed with the wiring when you switched from grid to inverter?
No, the person who the family member used to install the pump didn't to stick to code and I almost rode lightning because of it. Hence my insistence that I double and triple checked everything. Heck the inverter has a voltage read out that's visible.
>Do you have any other heavy draw items you could hook up the inverter to rule it out?
I attached a single phase load on both phases and it worked. Subsequent to the pump burnout, it turns out that the 48v inverter suffered shipping damage so I'm looking to have it repaired.
>Water is life, I get it...
Water is love, water is life...
>I've replayed the video about a half dozen times now, almost sounds like the pump is trying to prime.
The pump, without prime, will just stay on trying to do so. But there's an interconnect between the two wells that I used to prime "my" well before testing. I should note that the pump still "worked" in this state. After hitting the pressure target it would eventually shut off. The issue apart from the repeating surge, was that even the smallest water draw would cause it to buck again. I hope this helps you endure my madness.
>What's the switch on the front of the inverter for?
Power. Up is "power save" with short pulses to detect power, to return to pulsing if the inverter becomes unloaded again. Down was for continuous power, but low frequency inverters have transformers that make them wasteful at idle.

That would be worth looking into, however please remember that the pump worked with line power. The problem started when I converted to inverter power.

Gentlemen, I appreciate the help, but I'm going to buy-te the bullet on another pump and see where it takes me. I will report back on my findings.​

The line power doesn’t care how long the pump takes to prime. Your inverter just might care. Please look down the hole.

 

[OzSolar]

2 awg welding cable is rated for 150 amps at 105 celcius continuous. I'm using 200ah 12v deep cycle batteries and even the smaller inverter is rated for the surge draw.

Yet you still have a set up that wouldn't start the well pump. I once had a bad crimp torture me for an embarrassingly long time, it resulted in me replacing a perfectly fine inverter before I found it.

One more time, why not just switch to an inverter friendly well pump?

We will look forward to your report.

 

[42OhmsPA]

Do you have a harbor freight nearby?

https://www.harborfreight.com/lawn-garden/pumps/well-pumps.html

 

[1unluckyguy]

The line power doesn’t care how long the pump takes to prime. Your inverter just might care. Please look down the hole.

I will, thank you for your concern.

Yet you still have a set up that wouldn't start the well pump. I once had a bad crimp torture me for an embarrassingly long time, it resulted in me replacing a perfectly fine inverter before I found it.

One more time, why not just switch to an inverter friendly well pump?

We will look forward to your report.

The only things that can kill these SGP inverters are the knuckleheads amazon/ups/fedex. They never seem to show up without shipping scars.

Do you have a harbor freight nearby?

https://www.harborfreight.com/lawn-garden/pumps/well-pumps.html

I do! Sadly its only shallow well pumps. thanks for the heads up anyways.

Good night, gentlemen. I'll report in soon.

 

[1unluckyguy]

Gentlemen!

Thank you for your patience. Long story short: No available local plumber forced me to learn how to plumb, the hard way. Video evidence is as follows:

The panning of this video before engaging the inverter to the pump seeks to get ahead of critics who will attribute the difference to anything other than a pump swap.

Link to replacement pump.
There's no way that this pump is actually the 1HP rating it claims, as it takes ages to reach 50 psi from the customized cut-in pressure of 30 psi (stock cut on/off pressure is 20/40 psi, respectively) but it does draw about the same running wattage from other pumps in its class. However, for less than half the price of what's on offer at the local duopoly, I'm going to buy a spare just to spite them.

the hypothetical diagnosis for the issue is a failing well pump repeatedly activating a built in short protection due to the higher quality sine wave from the inverter causing an abnormal condition on the failing windings. The flatter peaks of line power would not induce this malfunction, but eventually the windings will fail or lock up and hum, rendering the pump inoperable. I honestly think I'm the first person on this dying internet who cared to document this event. Alternate opinions and hypotheses welcome. Please note that this is using the original 4 KW version of the inverter used in the first two videos, which is more than enough for the running draw of ~1300 watts.