30 Installation Guide APC Silcon 240-320kW 480V UPS
990-4049
External Connection
External Control Cables
External multicore cable has a 15-pin SUB-D male connector at either end. Connect pin 1 to
pin 1, and pin 2 to pin 2 etc. up to pin 15 - except pin 8, which need not be connected.
Shield is connected to plug cover at both ends.
Terminals X020 and X021 for control cables are located on parallel board. Connect X020 in
UPS1 to X021 in UPS2 and X020 in UPS2 to X021 in UPS3 etc. Connect X020 in last UPS to
X021 in UPS1.
(Cable is delivered with the UPS).
Power Cables
To optimize load-sharing in parallel operation, external power circuits must be “symmetrical”:
Power input and output cables must have same length and identical cross-sections.
Parallel Board
UPS 1 UPS 2 UPS 3
X020:15-pin SUB-D female
X021:15-pin SUB-D female
External multicore cable with 14 wires + shield
to other parallel units