Your
ground and
neutral should be bonded (easy test is to see if you have
continuity between the
ground and
neutral cams coming out of the
house disconnect). If that's not the case it could have something to do with your video problem, but every Skjonberg motor
distro I've ever worked with only used 3 phases +
ground so it wouldn't explain your motor issue.
If you're strictly using this service for 3
phase +
ground (a.k.a. only for motors) for testing purposes only you could try connecting the
system ground to the
house neutral and test the
system in that configuration. I've worked in buildings where a dodgy
ground has caused issues and this worked (All of them where out of the US and didn't have a bonded
neutral and
ground though).
I do not mean to insult your abilities or those of your crew and I'm not there to even say if this is really applicable, but I would say you should look at the possibility of it being a phantom issue. I've seen a lot of really good techs fighting to make something work take it apart and put it back together the same way and have it work perfectly afterwards. Is it possible that you had some kind of issue between the
power source and the motor control
system that could have been missed during initial trouble shooting with building
power but was "fixed" in the process of disconnecting from building
power and tying into the genny?
SIDE NOTES:
I've had to use a water pipe for a
ground in the past. It's not ideal, but in some buildings/locations it's the most effective option. Try driving a
ground spike in metro LA and you'll be lucky if the building electrician knocks you out before the underground utilities do.
If you find that the
ground and
neutral aren't bonded you can use some cam T's to bond them. One way is to put a T inline on both the
ground and
neutral lines between the
house disconnect and your
power disto. Then if you connect the 2 T's together your
ground and
neutral will be bonded. Ideally this should happen as close to the source as possible. It's not pretty, but it works.