Siemens 7SR12 Argus - Page 402

7SR11 & 7SR12 Applications Guide
Page 46 of 48 ©2017 Siemens Protection Devices Limited
Scheme 2 (Intermediate)
TRIP COIL
52a
52a
52b
-
Circuit
Breaker
BI
+ve -ve
+
BO 1 BO n
Remote
Alarm
BO
R
TRIP CCT n FAIL
H6 Scheme Notes:
BI = 19V (30, 48, 110, 220V supply)
BI = 88V (110, 220V supply)
R = 3K3 typical
Figure 5.4-2 Trip Circuit Supervision Scheme 2 (H6)
Scheme 2 provides continuous Trip Circuit Supervision of trip coil with the circuit breaker Open or Closed. It does
not provide pre-closing supervision of the connections and links between the tripping contacts and the circuit
breaker and may not therefore be suitable for some circuits which include an isolating link.
Scheme 3 (Comprehensive)
BI
+ve -ve
BO
BI
+ve -ve
TRIP COIL
52a
52b
-
Circuit
Breaker
TRIP CCT n FAIL
BO 1 BO n
Remote
Alarm
+
R
R
H7 Scheme Notes:
BI = 19V (48, 110, 220V supply)
R = 3K3 typical
Figure 5.4-3 Trip Circuit Supervision Scheme 3 (H7)
Scheme 3 provides full Trip supervision with the circuit breaker Open or Closed.