THREE PHASE OVER CURRENT + EARTH FAULT RELAY Block MC31A

50 / 51, 50N/ 51N

1.Three Phase Over current
2. Earth Fault
3. Inverse & Definite time trip Characteristics
4. 4 digit display
5. CT secondary 1A / 5A field selectable

TECHNICAL SPECIFICATIONS
1.0 Rated Current 1A or 5A (Field selectable)
2.0 Rated Frequency 50Hz ± 2.5 Hz
3.0 Auxiliary Power Supply 24V to 110V AC/DC ± 15% or 95V to 240V AC/DC ± 15%
4.0 Relay Settings :
Over Current (Is) 0.2 to 2.0 times In, in steps of 0.05In
Earth Fault (Os) 0.05 to 0.8 times On in steps of 0.05 On
Time Multiplier 0.1 to 1.6 in steps of 0.05 (independent settings for O/C & E/F modes)
5.0 Operating Characteristics Front panel programmable , using push buttons.
Time /Current Separate characteristics can be selected for O/C & characteristics E/F modes.
a) Normal Inverse (NI) 3s
b) Normal Inverse (NI) 1.3s
c) Very Inverse (VI)
d) Extremely Inverse (EI)
e) Definite Time (DT) 1s
f) Definite time (DT) 10s
g) Definite time (DT) 100s