Table of Contents
Advertisement
•
Apply 5 times the pick up current and the relay should trip in 2.03 sec. Acceptable time range between
1.88 and 2.13 sec.
EXTREMELY INVERSE CURVE
• Set the relay as follows:
51PT Settings Group
Curve
Time Dial
•
Apply 0.9 times the pick up current into phase C and the relay should not trip.
•
Apply 1.5 times the pick up current and the relay should trip in 3.87 sec. Acceptable time range between
3.24 and 4.65 sec.
•
Apply 5 times the pick up current and the relay should trip in 0.20 sec. Acceptable time range between
0.16 and 0.24 sec.
DEFINITE TIME
• Set the relay as follows:
51PT Settings Group
Curve
Time Dial
•
Apply 0.9 times the pick up current into phase A and the relay should not trip.
•
Apply 1.1 times the pick up current and the relay should trip in 1 sec. Acceptable time range between
0.97 and 1.03 sec.
•
Apply 4 times the pick up current and the relay should trip in 1 sec. Acceptable time range between 0.97
and 1.03 sec.
6.17. GROUND TIME OVERCURRENT UNIT (51NT)
Enable only 51NT function and its related trip, and set the pick up to the minimum possible.
INVERSE CURVE
• Set the relay as follows:
51NT Settings Group
Curve
Time Dial
•
Apply 0.9 times the pick up current into phase A and the relay should not trip.
•
Apply 1.5 times the pick up current and the relay should trip in 16 sec. Acceptable time range between
14.24 and 18.28 sec.
•
Apply 5 times the pick up current and the relay should trip in 4 sec. Acceptable time range between 3.87
and 4.10 sec.
VERY INVERSE CURVE
• Set the relay as follows:
51NT Settings Group
Curve
Time Dial
•
Apply 0.9 times the pick up current into phase B and the relay should not trip.
GEK-105593C
EXTREMELY INVERSE
0.05
DEFINITE TIME
1.0
INVERSE
1
VERY INVERSE
0.5
55
Advertisement
Table of Contents
