Loss Of Carrier; Logic For The Loss Of Carrier Function - GE MiCOM P40 Agile Technical Manual

P44x/EN AP/Hb6
(AP) 5-60
'DIST. Chan Recv'
'DEF. Chan Recv'
0
1
0
1
3.2.6.3

Loss of Carrier

In this mode the signalling equipment used is such that a carrier/data messages are
continuously transmitted across the channel, when in service. For a permissive trip signal to
be sent, additional information is contained in the carrier (eg. a trip bit is set), such that both
the carrier and permissive trip are normally received together. Should the carrier be lost at
any time, the relay must open the unblocking window, in case a line fault has also affected
the signalling channel. Two opto inputs to the relay need to be assigned, one is the Channel
Receive opto input, the second is designated Loss of Carrier (the inverse function to carrier
received). The function logic is summarised in Table 6: .
System
Condition
Healthy Line
Internal Line Fault
Unblock
Signalling Anomaly No
Table 6: Logic for the loss of carrier function
The window of time during which the unblocking logic is enabled starts 10ms after the guard
signal is lost, and continues for 150ms.
For the duration of any alarm condition (DDB: 'COS Alarm'), the "zone 1 extension" trip logic
will be invoked if the option 'Distance schemes / Z1 Ext on Chan. Fail' has been enabled.
Figure 38: Loss of carrier
'DIST. Chan Recv'
'DEF. Chan Recv'
0
0
1
1
'DIST. COS'
'DEF. COS'
0
1
1
0
Permissive
Loss of
Channel
Guard
Received
No No
Yes No
No Yes
Yes
'DIST. COS'
'DEF. COS'
0
1
0
1
MiCOM P40 Agile P442, P444
'DIST. UNB CR' 'COS alarm'
'DEF. UNB CR'
0 0
1 0
1 (Window) 1 (delayed)
0 1 (delayed)
Permissive Trip
Allowed
No
Yes
Yes, during a
150ms window
No
'DIST. UNB CR' 'COS alarm'
'DEF. UNB CR'
0 0
1 (Window) 1 (delayed)
1 0
0 1 (delayed)
Application Notes
Alarm
Generated
No
No
Yes, delayed on pickup
by 150ms
Yes, delayed on pickup
by 150ms