7SR105 Rho and 7SR17 Rho Applications Guide
©2018 Siemens Protection Devices Chapter 7 Page 25 of 31
Scheme 1 (Basic)
R
BI
+ve -ve
+
BO
1
BO n
Remote
Alarm
BO
R
TRIP COIL
52a
52b
-
Circuit
Breaker
H5 Scheme Notes:
BI = 44V (110, 220V AC/DC supply)
R = 3K3 typical
TRIP CCT n FAIL
Figure 4-3 Trip Circuit Supervision Scheme 1 (H5)
Scheme 1 provides full Trip supervision with the circuit breaker Open or Closed.
Where a ‘Hand Reset’ Trip contact is used measures must be taken to inhibit alarm indications after a CB trip.
Scheme 2 (Intermediate)
TRIP COIL
52a
52
a
52
b
-
Circuit
Breaker
BI
+
ve -ve
+
BO
1 BO n
Remote
Alarm
BO
R
TRIP CCT n FAIL
H6 Scheme Notes
:
BI =
44V (110, 220V AC
/DC
supply)
R = 3K
3 typical
Figure 4-4 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.
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