Specific Types Flashcards
21G
Ground distance
21P
Phase distance
27P
Phase undervoltage
27S
DC undervoltage relay
27TN
Third harmonic neutral undervoltage
27TN/59N
100% stator earth fault
27X
auxiliary undervoltage
27 AUX
undervoltage auxiliary input
27/27X
Bus / Line undervoltage
27/50
Accidental generator energization
32L
Low forward power
32H
High directional power
32N
Wattmetric zero-sequence directional
32P
Directional power
32R
Reverse power
37P
Underpower
49RTD
RTD biased thermal overload
50BF
Breaker failure
50DD
Current disturbance detector
50EF
End fault protection
50G
Ground instantaneous overcurrent
50IG
Isolated ground instantaneous overcurrent
50LR
Acceleration time
50N
Neutral instantaneous overcurrent
50NBF
Neutral instantaneous breaker failure
50P
Phase instantaneous overcurrent
50SG
Sensitive ground instantaneous overcurrent
50SP
Split phase instantaneous overcurrent
50Q
Negative sequence instantaneous overcurrent
50/27
Accidental energization
50/51
Instantaneous / time-delay overcurrent relay
50/74
CT trouble
50/87
Instantaneous differential
51G
Ground time overcurrent
51LR
AC inverse time overcurrent (locked rotor) protection relay
51N
Neutral time overcurrent
51P
Phase time overcurrent
51R
Locked / stalled rotor
51V
Voltage restrained time overcurrent
51Q
Negative sequence time overcurrent
52a
AC circuit breaker position (contact open when circuit breaker open)
52b
AC circuit breaker position (contact closed when circuit breaker open)
59B
Bank phase overvoltage
59P
Phase overvoltage
59N
Neutral overvoltage
59NU
Neutral voltage unbalance
59P
Phase overvoltage
59X
Auxiliary overvoltage
59Q
Negative sequence overvoltage
60N
Neutral current unbalance
60P
Phase current unbalance
64F
Field ground protection
64R
Rotor earth fault
64REF
Restricted earth fault differential
64S
Stator earth fault or sub-harmonic stator ground protection
64TN
100% stator ground
67G
Ground directional overcurrent
67N
Neutral directional overcurrent
67Ns
Earth fault directional
67P
Phase directional overcurrent
67SG
Sensitive ground directional overcurrent
67Q
Negative sequence directional overcurrent
78V
Loss of mains
81O
Over frequency
81R
Rate-of-change frequency
81U
Under frequency
87B
Bus differential
87G
Generator differential
87GT
Generator / transformer differential
87L
Segregated line current differential
87LG
Ground line current differential
87M
Motor differential
87O
Overall differential
87PC
Phase comparison
87RGF
Restricted ground fault
87S
Stator differential or percent differential
87T
Transformer differential
87V
Voltage differential