Let the fun begin !!! ???

[PAULRO]

I checked the wiring and it's all fine, once i power up it trips. if i reset it and and power up again but this time restricting the MCB ( momentarily) from tripping then it works. so i thought i would rewire it temporarily and take the relay out of the PSU circuit and just go from main switch to MCB to primary coil of PSU and that too works a treat( MCB not tripping ).
ya, i will leave the e/stop hardwired to dropout the PSU but inform MACH3 through the BOB that an e/stop has occurred so it can do its duty.