I experimented again with the power supply and g540 , thismorning.

My other power supply, is only 30 Volt max 10 amps, but I can see the current draw on the system was down around 2-3 amps ( don't know how accurate that is ) I could not get the fault with the other system.

I then tried the keeling 48 volt 12.5 amp
with voltmeter on the output, it was steady but faulted at 48 volts, I adjusted the voltage pot to 49.9 volts, again stable, the multimeter coult not detect movement, but the fault happened faster at 50 volts, I dropped voltage to 46 volts, and faulted after 5 minute, then I tried 44 volts, and it took lots of simultaneous input, but it eventually gave a fault at 44 volts, I wound the pot all the way back, so it's now at 42.5 volts, and there was no fault so far.

sound like there is a feedback issue coming from somewhere?

Is there anything I can do to try make it work at 48 / 50 volts