Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1204
| Posted: 10:59pm 25 Dec 2022 |
Hi Mike, welcome to the forum, I will add my support for some of the comments already posted.
1) Slow starts are not for the loads it is for the toroidal and avoiding a saturation and bang event.
2) Soft starting a compressor is asking for trouble in my first-hand experience it is the only way I killed my inverter with normal usage. The second way was playing with software changes, throwing caution to the wind and applying the changes to the inverter & Toroid without first bench testing waveforms with a CRO.
3) Always let the inverter finish soft starts unless the load is resistive, in my opinion inductive and capacitive loads should also only be connected after soft start is finished. Best to just turn on the AC circuit breaker manually for all loads after soft start is done.
4) I also have witnessed a 2kW HF inverter start fridges and all typical household devices for night-time usage without issue so yes, it is horses for courses. I suspect that either you got lucky with your choice of HF brand or it was just a lucky one or/and built really well.
5) Having used thousands of Nichicon capacitors for 20 years with voltages from 16V to 450V my experience is the opposite to yours, I am also confident that applying a brown shrink wrap to an inferior part but labelled the same as a Nichicon does not make it a Nichicon. Ali has some expert forgers for electronic parts, avoid capacitors, Mosfets and integrated circuits, yes they even Laser etch part numbers and logos to semiconductors and look like the real thing.
6) I went to the trouble of automating my soft charging of the input capacitors first before soft starting the inverter. Not implemented yet will be an output relay that connects the AC output automatically after soft start finish.
7) When I want reliable parts I buy them from Digikey, Element14, RS components or lastly LCSC especially for the HY#### Mosfets and all semiconductors to date (I have purchased) appear to be genuine.
Have fun and please post your progress, successes and failures it's all good reading and helps others !