Siemens 7SR224 Technical Manual page 348

Scheme 2 (Intermediate)
+
R
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)
+
R
R
Figure 5.4-3: Trip Circuit Supervision Scheme 3 (H7)
Scheme 3 provides full Trip and Close supervision with the circuit breaker Open or Closed.
©2010 Siemens Protection Devices Limited
BO
TRIP CCT n FAIL
BI
+ve -ve
BO 1 BO n
Remote
Alarm
7SR24
BO
TRIP CCT n FAIL
BI
+ve -ve
BI
+ve -ve
BO 1 BO n
Remote
Alarm
7SR24
7SR224 Argus Applications
52a
TRIP COIL
52a
Circuit
Breaker
52b
H6 Scheme Notes:
BI = 19V (30, 48, 110, 220V supply)
BI = 88V (110, 220V supply)
R = 3K3 typical
52a
TRIP COIL
Circuit
Breaker
52b
H7 Scheme Notes:
BI = 19V (48, 110, 220V supply)
R = 3K3 typical
Chapter 7 Page 49 of 50
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