Posted by Hacksaw on 18/08/2019 20:04:46:
Umm …I've read that the electronics in mig welders dislike being run from a generator , or rather the generator needs to be a much larger kw for it to work ? Well , today i used my newish Lidls variable speed 1200w angle grinder with my Honda EX500 genny…( 500w ) It ran it ok to start with, I didn't overload it , as obviously it wasn't making much power running on 500w ..and i was only using a 1mm disc to cut off a 8mm bolt so i wanted it to keep spinning fast . When i went to cut off a second bolt , the grinder wouldn't work.. Nor on mains .. Fetching my second Lidls grinder , that worked ok with genny power and i finished the job .. Do you think i've damaged the variable speed board ? I can't see that I could have burnt out the motor windings…
Small generators are notorious for poor voltage regulation and mucky output. The waveform can be non-sinusoidal and spiky, while the output voltage swings wildly with the load. A simple generator won't be good at handling intermittent loads – like an angle grinder – and is likely to over-volt the angle-grinders electronics.
Root cause is the motor's throttle reacts too slowly, first failing to accelerate fast enough and then failing to slow down quickly when the load drops. Older generators are particularly prone to voltage swings because their regulators are slow acting, perhaps even a mechanical cut-out.
Apart from the cheap basic models, modern generators are better regulated with the posh ones putting an inverter between the generator and user to clean up the output. They still don't like being overloaded, but they're less likely to damage electronics.
An oversized generator is recommended for a varying loads like an angle grinder because the larger mass of it's spinning parts store enough inertial energy to smooth out peaks and troughs.
Dave