Thanks for the replies.
My pic hardware / software drives both IR2113 Hi / Lo side fet drivers, with the output transformer
still in place. I connect a 1 K.W. tungsten lamp across the secondary as a load. And disconnect the secondary from the grid connect side for test purposes. The inverter runs as a normal inverter.
My interpretation of the 30 ohm resistor across the neutral relay contacts is that its for grid load sensing before the device connects fully ?
My intention is to not use the inverter / capacitor parts of the inverter again. Have repaired it to many times. The capacitors are 300 volt wired in series in groups of two. The P.C.B. board design has got the fet Hi / Lo driver chips very remote from the fet input stages in amongst the high voltage / current capacitor section. Very little thought went into the original design.
I was just going to use the original control C.P.U. / P.C.B. to drive a properly designed H bridge Mitsubishi I.G.B.T. out put stage with the capacitors and high voltage / current circuits remote from the C.P.U.
Just need to get over the K1 open.