Specifications

7SR242 Duobias Applications Guide

Scheme 2 (Intermediate)

+ve -ve

TRIP COIL

52a

52b

Circuit

Breaker

BO 1 BO n

Remote

Alarm

H6 Scheme Notes:

Resistor:

30V dc Nominal: R = 3K9

48V dc Nominal: R = 5K6

110V dc Nominal: R = 15K0

TRIP CCT n FAIL

Figure 5-5: 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)

Figure 5-6: Trip Circuit Supervision Scheme 3 (H7)

Scheme 3 provides full Trip and Close supervision with the circuit breaker Open or Closed.