TSW series inverter is well-known quality products in the world.
Need 50 Hz, or 230/115v instead of 240/120? Remove ALL power sources from the inverter – grid AC and battery DC. Press the standby button and let the inverter try to start up if it hasn’t gone dead already. It should just make it through the countdown and bleep out. Remove the four screws on the top cover and try to lift it off. It’s a pretty tight fit and you may need to pry carefully. I used a plastic knife as not to scratch the paint.
Once the cover comes up, carefully move it up and to the right and push the plastic eject levers on the LCD board’s connector apart. The ribbon cable should come free. Set the cover aside.
The two dip switches are on the top of the control board, the same board where the ASnet and temp sensor cables go in.
Switch 1 – closest to the battery terminals – sets voltage. Down is 240, up is 230.
Switch 2 – is the frequency, down 60, up 50.
After setting these, blow out any dust that’s accumulated if the inverter was previously used, reconnect the LCD cable, put the cover back, and restore power. If you didn’t get the cable back in, the inverter will play dead till you fix that. No harm done really.
There are a lot of other parameters editable from PC software(AIM).