"Improving" my Power Jack Inverter

want to power a 1/2hp 240V 3-Wire pump. My initial attempts were failures. The inverter shut down within a few seconds.          a 230v pump motor draws 9 amps when it's running, probably it's 3/4 to 1 horsepower .

The  1/2 hp  pump   at 5 amps  is  1200 watts  and should start .      Try to start a  microwave oven  which is 3000 watts .        Try 4/0 cable  copper wires  .         The battery connection inside may be loose .       Try  turn on a hair dryer first  and  then  turn on the pump  second .       Your inverter look the same  but mine 8 kw  PJ is different .   

The well pump is less than 15A to start, and it also has a start capacitor in the pump control box. My guess the starting surge is about 3000W. I will try again when it's cooler.  I recently learned how to start my 800W 115V refrigerator, and it was your hair dryer trick.

 I recently learned how to start my 800W 115V refrigerator, and it was your hair dryer trick.

My  8kw  PJ  with the rev 10.3 control board  can run a 5 hp air compressor  by  running it on the grid  for  2 minutes  to charge the capacitor         then  connect  directly th the 8 kw PJ   to run the 5 HP shop compressor  .    Running  2 minutes  on grid  is a trick to charge the  capacitor on the  compressor   and it also work to start  the 4 ton  heat pump  with my  15kw PJ  with the rev 10.3 control board  .       I  run the heat heat pump 3 minutes on grid and then  switch  to directly connect to the  15 kw  PJ  .   I found  that my   15kw  PJ  advertise on ebay auction  was actually  a  20 kw PJ  prototype  from Walnut  with the ASL9.0  transformer .       Your 8kw PJ  should easily  start any  1/2  hp  motor  buy never know what is actually  inside any  PJ case .      

It has 2 big caps and the ASL-2 transformer. I am slowly learning the tricks, so my next attempt might work.

My 10k upower is also 2 caps and asl2.

Running RU7088 FETs which failed fairly quickly

I suspect it was during pump start as that was my only load and running current doesn't get it hot.

I wasn't watching it

I wouldn't expect the choke to help.

My clamp meter showed a 56A inrush current when running it from utility power so the initial pulse is very heavy

I have a 1/2hp pump meant to be protected by a 15A fuse. Wouldn't that mean the inrush current would be less than 15A?

Inrush can be well above fuse as it takes time to heat the fuse

 I'll  continue to try to start and run the pump. I'll add a choke, and just replace the mosfet boards, if they blow. Live and learn. My initial problem was probably voltage sag, but I think I've solved that.

I'll  continue to try to start and run the pump. I'll add a choke, and just replace the mosfet boards, if they blow. Live and learn.

I  learn enough in testing the rev 11.1 control board  that   I never blow up any FETs .    I  overload  with  240v  30 years oven and 240v water heater and  5 hp air compressor  and    4 ton  heat pump  and always  red light alarm in one second .        I will be surprise if your rev 11.3  control board will blow up a single FETs .     The rev 10.3  or rev 9.0  control board is a different  story  as I blow up  over 100 FETs in testing .     The  overload  last 7 seconds and all the FETs  will blow up and I have to  manually shut down before 5  seconds  to save the FETs  .     

I'll do my pump testing once I finish the 115V house wiring and such. The odd thing is that Power Jack is suddenly warning us recent buyers (after we buy, with stickers on the inverter) to buy their chokes. Maybe it's to make extra money, and to limit their liability if the inverter fails. I wish I knew if the smaller aftermarket choke was enough. 

I bought 5 20A 50uH chokes for $13 total. I plan to put one on each inverter output hot and neutral line.