x/EN PL/Na7 
 
 7-
 
MiCOM P74
 
 
1.12  Relay output contact mapping 
The default mappings for each of the relay output contacts are as shown in the following 
table: 
Central Unit P741: 
Relay 
Contact 
Number 
P74x Relay Text 
P74x Relay 
Conditioner 
Function 
1  Relay Label 01 
Pick-up 0/0  Trip 87BB or 50BF backtrip or 
overcurrent / earth fault trip (fixed) 
2  Relay Label 02 
Pick-up 0/0  Trip 87BB or 50BF backtrip or 
overcurrent / earth fault trip (fixed) 
3  Relay Label 03 
Pick-up 0/0  Trip 87BB or 50BF backtrip or 
overcurrent / earth fault trip (fixed) 
4  Relay Label 04  Pick-up 0/0  Trip zone 1 
5  Relay Label 05  Pick-up 0/0  Trip zone 2 
6  Relay Label 06  Pick-up 0/0  Circuit fault or PU error 
7  Relay Label 07  Pick-up 0/0  Zone 1 or zone 2 blocked 
8  Relay Label 08  Pick-up 0/0  Check Zone fault 
Peripheral Unit P742: 
Relay 
Contact 
Number 
P74x Relay Text 
P74x Relay 
Conditioner 
Function 
1  Relay Label 01 
Pick-up 0/0  Trip 87BB or 50BF backtrip or 
overcurrent / earth fault trip (fixed) 
2  Relay Label 02 
Pick-up 0/0  Trip 87BB or 50BF backtrip or 
overcurrent / earth fault trip (fixed) 
3  Relay Label 03 
Pick-up 0/0  Trip 87BB or 50BF backtrip or 
overcurrent / earth fault trip (fixed) 
4  Relay Label 04  Pick-up 0/0  Circuit Breaker failure 
5  Relay Label 05  Pick-up 0/0  Circuit Breaker failure or out of service 
6  Relay Label 06  Pick-up 0/0  Circuit Breaker failure retrip 
7  Relay Label 07  Pick-up 0/0  Trip or Dead Zone Fault 
8  Relay Label 08  Pick-up 0/0  Circuit Breaker or Isolator status alarm 
9  Relay Label 09  Pick-up 0/0  Circuit Breaker failure retrip phase A 
10  Relay Label 10  Pick-up 0/0  Circuit Breaker failure retrip phase B 
11  Relay Label 11  Pick-up 0/0  Circuit Breaker failure retrip phase C 
12  Relay Label 12  Pick-up 0/0  Not Mapped