Guru
Joined: 08/02/2015
Location: New ZealandPosts: 1207
| Posted: 12:25am 02 Apr 2026 |
We have a similar problem at our off grid site, the under ground septic tank has a pump in it that grinds + pumps sewerage from the tank to council system across and under the road.
The pump won't start off our 6KVA low frequency inverter, but runs off the diesel generator; real pain having to start the generator several times a week just to run the pump.
Was thinking of making a physically small but high power 48dc-230vac inverter, that was phase locked to the main inverter; start the pump on that and switch over to the main inverter after 3-4 seconds. Have a small toroidal core approx 1.5KW continuous rating, it may run at > 8KVA for a minute or so before it heated up too much.
Could replace the pump for a lower powered one, but they are very expensive, similar could replace the main inverter with a larger one, again expensive.
Mike
Edited 2026-04-02 10:25 by Solar Mike