External connection – APC SILCON 10-40KW 400V UPS User Manual
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External Connection
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Installation Guide APC Silcon 10-40kW 400V UPS
17
4.2
System Integration Interface
System Integration Interface (SII) is the control link between UPS and system main switches 
as shown in above diagram. The purpose of the SII is to ensure correct operation of switches 
without losing system output power.
Auxiliary contacts on the main switches transmit the SII board inputs. Lamps on Service 
Bypass Panel and Battery Breaker Box/Battery Cabinet indicate “green light” for operation of 
output switches.
SII board also integrates input facilities for emergency shut-down and temperature 
compensation of charge voltage for external battery (use with battery monitor). “Battery 
operation” and “Common fault” are two main SII board status relay signals.
NOTICE!
Consistent use of designations (Q001, Q002, Q003, H002, H003) in diagrams simplifies 
information exchange.