Inactive timer
The Inactive timer module calculates the number of days the circuit breaker has
remained in the same open or closed state. The value is calculated by monitoring
the states of the POSOPEN and POSCLOSE auxiliary contacts.
The number of inactive days INADAYS is available as a service value. The initial
number of inactive days is set using the InitInactDays parameter.
Alarm limit check
MONALM is initiated when the number of inactive days and hours exceed the limit
value defined by the InactiveAlDays and InactivAlHrs setting. The alarm signal
MONALM can be blocked by activating the binary input BLKALM.
15.4.7.7  Circuit breaker spring charge monitoring
GUID-F850A940-7890-4C37-8B31-6C7D5B30E582 v11
The circuit breaker spring charge monitoring subfunction calculates the spring
charging time. The operation is described in figure 277.
SPRCHRD
BLOCK
BLKALM
Spring charging 
time 
measurement
Alarm limit 
Check
SPRCHRST
RSTSPCHT
SPCHT
SPCHALM
IEC12000621 V2 EN-US
Figure 277: Functional module diagram for circuit breaker spring charge
indication
Spring charging time measurement
Spring charging time calculation will be initiated as soon as the circuit breaker is
closed and charging motor starts (NO contact of the device is connected to
SPRCHRST) to store the energy in the close spring. An indicator provided in the
circuit breaker is displayed when the spring is completely charged. This status is
taken through NO contact and then connected to SPRCHRD.
The binary input SPRCHRST indicates the start of circuit breaker spring charging
time. SPRCHRD indicates that the circuit breaker spring is charged. The spring
charging time is calculated from the difference of these two signal timings. Spring
charging indication is described in figure 
277.
The last measured spring charging time SPCHT is provided as a service value. The
spring charging time SPCHT can be reset on the LHMI or by activating the input
RSTSPCHT.
1MRK 505 394-UEN A Section 15
Monitoring
Line differential protection RED650 2.2 IEC 551
Technical manual