No Power on some Outlet Groups (SRT8KRMXLI)

[do1212]

TLDR: SRT8kRMXLI, 3phase 230V input, only outlet group 2 ist working, not one and three - any advice?

yesterday i had some bigger trouble installing a new UPS

Note that this is a german installation, so the 8kVA online UPS is fed by 230VAC 3-phase 16A input

I burned through two or three breakers wich caused a major unplanned downtime at our customer
I'm not an electrician so all the hardwiring was done by an external electrician.

1. The first mistake was, we overlooked the phase bridge was still mounted and that was when the first breaker burned through.
2. We then noticed that only one of the three outlet groups was delivering power. I restarted all outlet groups including the working one while there was a load attached (approx. 650VA) wich burned antother breaker. And i don't know why. Of course, restarting outlets with attached load is not ideal but the load was not so high it should cause events like this.
The UPS also wrote down an internal error wich caused it to switch to bypass mode, also not understanable for me. The next event said "switching to battery power due to distorted input" wich is expectable because one of the three pahses was down

The problem is the breaker design for the room. There are 6 circuits in the server room: F5.1.1 to F5.1.6.
F5.1.1, F5.1.2, F5.1.3 are the three phase input for the UPS, the other three are single phase normal input, each one 16A.
But that were not the breakers burning through.
F5.1.1 and F5.1.4 are both L1, .2 and .5 are L2, .3 and .6 are L3.
After those first breakers is a second row of breaker, for each phase a 35A-breaker. These ones got burned through. Don't know why.

After the electrician switched the breaker, we restartet outlet group 1 and 3 again. Still no power. Only outlet group 2 is working.
Any idea why only one outlet group is working?
This makes technically no sense as internally, the UPS is just a single pahse...

I still have check if the circuit breakers of the singel outlet groups hav tripped, but why should they have tripped? There was never a load more than 5A / 1100W on those outlet groups. Also why is Group two then still working?
Of course i will also contact APC support on that issue.