There is also a 2 to 3 phase converter that powers up to 3 HP but which has a problem starting a couple of my machines in the winter when the oil is v ery thick. I have been trying to rig up a phase comparison device to determ ine if the frequency of the set is correct, by connecting the alternator ou tput of one phase to the incoming mains supply via two 240 volt bulbs in se ries. this has worked on several generators over the years and the lights b eat against the mains voltage and when the speed is correct to give 50 Hert z the beating stops and the lights stay on or off. It works very well, how ever when I tried to connect one phase from the Lister to the mains through my two bulb box, the earth leakage trip tripped. I cannot see why this sh ould be unless there is a neutral to earth leak somewhere. A chase around with a meter did not reveal anything that I did not expect but I am wonderi ng if the neutral wire from the alternator should be strapped to the frame and / or run to an earth pole in the outside ground. The incoming mains is earthed by a copper rod below the electric meter.
A small portable single phase generator which is not earthed anywhere but w hich has an earth wire out just connected to it's chassis, performs perfect ly and as I can also test this against the Lister with no problem I have se t the little engine as accurately as I can to the mains frequency and then connect this to the Lister set and re-synchronized it. I want to mount the frequency setting facility permanently so I would rather fix the problem. Would it be better to run an earth wire across the workshop or bang a galva nized earth pole into the ground outside adjacent to the generator. set
What should I do about this tripping, is it an earthing problem or what? Any comments would be appreciated. By the way I have a very high quality 30 HP motor, (22Kw) that I am thinking of scrapping. It can be seen running and is really too good to scrap.