System information

GRAVITAS SABRE SERIES
INSTALLATION &OPERATING MANUAL
Manual No. SABRE-4 Page 20 11/27/07 sabre-man
1.2.1.10.2 Off-line mode
The SCR2 that is on the inverter side will be detected when the STS operates in off-line mode. When SCR2 is short,
the system will continue to power the load from the Utility. An “SCR2 short alarm” will be sent to the controller via
the CAN bus.
Mains
Inverter
Load
Backfeed Relay
Bypass Relay
SCR1
SCR2
Mains
Inverter
Load
Backfeed Relay
Bypass Relay
SCR1
SCR2
Backfeed relay closed
SCR2 is normal
SCR2
short
Mains power the load
Inverter power the load
Backfeed relay closed
Fault
Figure 9 SCR2 short in off-line mode