
Quick Start Guide
Flatpack2 PS System, 4U, SP2-based
356825.103, 2v0 -2011-09
18
Mains Phases versus Rectifier ID
Phase Balancing & Monitoring
When
Flatpack2
systems are fed with a 3-phase AC Mains input circuit, each rectifier is internally
connected to the 230VAC phases, in such a pattern that loads the 3 phases evenly.
The distribution of rectifiers among the phases is implemented both via internal wiring to the
power shelves, and how the shelf’s back-wiring card routes the phases to each rectifier position.
There are 3 types of shelves: 4AC, 4AC-3kW and 2AC power shelves. Read also the
Identifying
Power Shelves
section, page14.
Plug-and-Play Rectifiers versus Phase Monitoring
When a rectifier is
hot plugged in a power shelf for the first time
, the system’s master
controller
assigns the next available ID number to the rectifier, starting with “01”. The controller registers the
rectifier’s Serial Number and ID number.
When a
previously installed (hot plugged)
Flatpack2
rectifier is inserted in a power shelf, the
master
controller “recognizes” the module, and assigns the same ID to the rectifier. In other words,
the controller and the rectifier “remember” the assigned ID number, even after removing and
reinserting the rectifier in the shelf.
To achieve a more controlled ID assignment, you should always insert & hot-plug new
Flatpack2
rectifiers
in the indicated power shelf position,
one module at a time, starting with ID number
1, 2, 3
, and so on. The sequence is indifferent after ID number 6. You find more information on
page 19.
This position-versus-ID number relationship is very important, as the controller always uses
rectifier IDs 01 and 04 to monitor mains phase L1, rectifier IDs 02 and 05 to monitor mains phase
L2 and rectifier IDs 03 and 06 to monitor mains phase L3. When both rectifiers, monitoring the
same phase, report that the
mains phase voltage is lower than the configured limit
, then the
controller broadcasts a “Mains Phase Lx” warning (one phase has failed).
For example: accidentally inserting a rectifier with ID02 in a power shelf position internally
connected to mains phase 1, will cause the controller to monitor phase 1 “thinking“ it monitors
phase 2. Then a phase 1 fault will be alarmed as a phase 2 fault.
Appendix
AC Mains
Mains
Three-phase, 230VAC
L1
L2
L3
230VAC
AC
Mains
02
05
08
n
Phase 2
03
06
09
n
Phase 3
01
04
07
n
Phase 1
Flatpack2
rectifier
Mains
Three-phase & N, 400VAC
ID number
(Assigned
CAN bus
address)
230VAC
L1
L2
L3
Mains
400VAC, 3ph+N
N
01
04 07
n
Phase 1
03
06
09
n
Phase 3
Phase 2
02
05 08
n
Load Balancing of Mains Phases
Even distribution of
Flatpack2
rectifiers on the Mains phases
Mains
One-phase, 230VAC
01
02
03
n
N
(L2)
230VAC
AC
Mains
L
(L1)