Unsure relays/mach2/3

[Bear]

Hi all,
am wondering why my machine blows "main" fuses if main power is turned "on" before computer is "on" or for that matter "off".
if i start computer (XP) and then energize Power&BOB things are fine . If I turn computer off first (shutdown Mach ) then
I loose 2 of 3 fuses. ? is I think I have the motor (3ph440) hooked to the relay outputs (M3 to one relay & M4 to another
and works fine ) and maybe I should change the "Hi" to" Low" ?   
Thanks,
 Bear

[Brian Barker]

Could you please tell us more about what you have for hardware? Also if you post this in the mach3 forum I think you will get more help