New Member
Hi all,
First of all here is my system:
-48 volt
-28kwh using Nissan leaf batteries
-Epever 80amp mppt charge controller
-AMS 5000 watt, 10000 watt peak, 30amp ac inverter.

I used a 10awg, 100ft super heavy duty extension cord to plug in my 1hp, 110/12amp, 220/6 amp water pump. I checked and the pump was getting about 121 volt from the cord but it just couldnt get up to 65 psi I had set. Plug into my house with the same voltage, no problem getting up to that pressure. I even get a 220v transformer, rewire my water pump for 220v and get 243 at the pump, that didn't work either. Any suggestions would be really appreciated.


Solar Honey Badger
What about the Hz?

It's possible that the inverter just puts out a lower voltage inherently, or it does so due to a voltage drop in the DC input.


Offgrid Cabineer, N.E. Ontario, Canada
65PSI is pretty high, heck, I cutoff at 45PSI. Deep well pump 260' down to a 50 Gal pressure tank then 75' to house.

1st, try to lower the pressure to even 50 PSI and see it will take it to that pressure. Watch your cutoff pressure switch, some of them can be a real /^&&#*&(&#&*&_)+/ if you know what I mean. The first thing I always look at is the pressure switch because they can go flaky out of the blue, especially if there has been a lot of cycling on the contacts.

The frequency range: The Aims 5K inverter I see is:
This is a High Frequency unit I believe, HIgh frequency units do not drive motors / compressors etc well. They are good for electronics & low loads but not inductive loads. Just checked the owners manual, not Low Frequency. This is why your pump works fine on Grid Power but not from your inverter. I also have a 3000W High Frequency Inverter (an emergy one I have) but that will not run my Grundfos SQ-5 Soft-start 120V pump either which starts at 500W and ramps to 1100W @ Cutoff, yet my Samlex EVO-4024 and even my retired Yiyen APC3024-LF Low Frequency Inverters never even blinked. The water pump also does NOT like my Construction Generator (9kw Champion Mod Sine) but has no issue with my 3kw Inverter Generator which is Pure Sine Low Frequency. Gensets are peculiar depending on manufacturer tough.

Please review this as it explains the difference between High & Low Frequency.

Hope it helps, Good Luck.


New Member
What about the Hz?

It's possible that the inverter just puts out a lower voltage inherently, or it does so due to a voltage drop in the DC input.
You got it. It was the Hz. It was switched to 50 hz instead of 60. I set it to 60, power the inverter off for a minute then power it on and it powers the water pump perfectly. Thanks for your help.


New Member
It's been ok. It never get hot and it pretty quiet. However it did shut off a few times, my guess is my water pump is pulling too much amps... It says 40 amps on the shunt leading to the inverter, but aim 5k is 5k continuous and 10k peak so it should be able to handle the surge but my case it couldn't. I can get it working by turning it off for about 10 sec then back on. it's not a big deal but it's kinda a pain in the ass if you are in the shower. Also if there is a way I can change the low voltage cut off, that would be great.


Photon Sorcerer
If the voltage hadn't shown up as good, I would have said run at 220V. But you already did.
I still think you should use 220V. Some of my motors/pumps didn't want to start at 110V.
The starting surge current is far higher, but brief enough your handheld DMM won't show.
Having half the current & voltage drop out of twice the operating voltage should start it with less strain.
So long as the transformer's current handling isn't the bottleneck.

Sounds like you're at the edge of what the inverter can operate.
Reduce pressure setting?
Run at 55 Hz if adjustable?
Find a suitable run capacitor for the motor which reduces VA draw?