GE 469 User Manual

5–62 469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
For example, if a pump is cooled by the liquid it pumps, loss of load may mean that the
pump overheats. In this case, enable the undercurrent feature. If the motor loading should
never fall below 0.75 × FLA, even for short durations, the
UNDERCURRENT TRIP PICKUP
could be set to “0.70” and the
UNDERCURRENT ALARM PICKUP to “0.75”. If the pump is
always started loaded, the
BLOCK UNDERCURRENT FROM START settings should be disabled
(programmed as “0”).
The
UNDERCURRENT ALARM DELAY or UNDERCURRENT TRIP DELAY is typically set as quick
as possible, i.e. 1 second.
5.7.5 Current Unbalance
PATH: SETTINGS ZV S6 CURRENT ELEM. ZV CURRENT UNBALANCE
For the 469 relay, unbalance is defined as the ratio of negative-sequence to positive-
sequence current, I
2
/ I
1
, if 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 when a motor is lightly loaded. If enabled, a trip
and/or alarm occurs once the unbalance magnitude equals or exceeds the
CURRENT
UNBALANCE ALARM(TRIP) PICKUP
for a period of time specified by the CURRENT
UNBALANCE ALARM(TRIP) DELAY. If the unbalance level equals or exceeds 40%, or when
I
avg
≥ 25% FLA and current in any one phase is zero, the motor is considered single phasing
and a trip occurs within 2 seconds. Single phasing protection is disabled if the unbalance
trip feature is turned “Off”.
When setting the
CURRENT UNBALANCE ALARM(TRIP) PICKUP level, note that a 1% voltage
unbalance typically translates into a 6% current unbalance. Therefore, to prevent nuisance
trips or alarms, the pickup level should not be set too low. Also, since short term

CURRENT [
CURRENT UNBALANCE
ALARM: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN ALARM
RELAYS:
Range: Alarm, Alarm & Auxiliary2,
Alarm & Aux2 & Aux3,
Auxiliary2, Aux2 & Aux3,
Auxiliary3
MESSAGE
CURRENT UNBALANCE
ALARM PICKUP: 15%
Range: 4 to 40% in steps of 1
MESSAGE
CURRENT UNBALANCE
ALARM DELAY: 1 s
Range: 1 to 60 s in steps of 1
MESSAGE
CURRENT UNBALANCE
ALARM EVENTS: Off
Range: On, Off
MESSAGE
CURRENT UNBALANCE
TRIP: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN TRIP
RELAYS:
Range: Trip, Trip & Auxiliary2, Trip &
Aux2 & Aux3, Trip & Auxiliary3
MESSAGE
CURRENT UNBALANCE
TRIP PICKUP: 20%
Range: 4 to 40% in steps of 1
MESSAGE
CURRENT UNBALANCE
TRIP DELAY: 1 s
Range: 1 to 60 s in steps of 1

GE 469 Specifications

General

Brand	GE
Model	469
Category	Relays
Language	English