GE Multilin 469, Instruction Manual

Page: 261 / 338

CHAPTER 6: ACTUAL VALUES
469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL 6–11
6.3 A2 Metering Data
6.3.1 Current Metering
PATH: ACTUAL VALUES
ZV
A2 METERING DATA
Z
CURRENT METERING
All measured current values are displayed here. The
CURRENT UNBALANCE
is defined as the
ratio of negative-sequence to positive-sequence current, I
2
/ I
1
when the motor is
operating at a load ( I
avg
) greater than FLA. If the motor I
avg
is less than FLA, unbalance is
defined as I
2
/ I
1
× I
avg
/ FLA. This derating is necessary to prevent nuisance alarms and
trips when a motor is lightly loaded. The
U/B BIASED MOTOR LOAD
value shows the
equivalent motor heating current caused by the unbalance k factor.
„
CURRENT [
Z
]
METERING
A: 0 B:
0
C: 0 Amps
Range: 0 to 100000 A
MESSAGE
AVERAGE PHASE
CURRENT: 0 Amps
Range: 0 to 100000 A
MESSAGE
MOTOR LOAD:
0.00 x FLA
Range: 0.00 to 20.00 x FLA
MESSAGE
CURRENT UNBAL-
ANCE:
MESSAGE
U/B BIASED MOTOR
LOAD: 0.00 x FLA
Range: 0.00 to 20.00 x FLA
MESSAGE
GROUND CURRENT:
0.00 Amps
Range: 0.00 to 5000.00 A. Not seen if
Ground CT is set as “None”.
MESSAGE
A: 0 B:
0
Range: 0 to 5000 A. Seen if Phase
Differential CT has 1A/5A
Secondary