Neutral Instantaneous Overcurrent (50N) - GE 339 Instruction Manual

S3 PROTECTION

Neutral instantaneous overcurrent (50N)

6–64
The relay has one Instantaneous Overcurrent protection. The settings of this function are
applied to the calculated neutral current for producing pickup and trip flags. The Neutral
IOC pickup flag is asserted, when the neutral current is above the PKP value. The Neutral
IOC operate flag is asserted if the element stays picked up for the time defined by the
Neutral IOC Delay setting. If the pickup time delay is set to 0.00 seconds, the pickup and
operate flags will be asserted at the same time. The element drops from pickup without
operation, if the neutral current drops below 96 to 99% of the pickup value.
The following path is available using the keypad. For instructions on how to use the
keypad, please refer to Chapter 3 - Working with the Keypad.
PATH: SETPOINTS > S3 PROTECTION > NEUTRAL IOC
NTRL IOC1 FUNCTION
Range: Disabled, Latched Alarm, Alarm, Trip
Default: Disabled
For details see Common
NTRL IOC PKP
Range: 0.05 to 20 x CT in steps of 0.01 x CT
Default: 1.00 x CT
This setting sets the neutral instantaneous overcurrent pickup level specified as times CT.
NTRL IOC DELAY
Range: 0.00 to 300 s in steps of 0.01 s
Default: 0.00 s
This setting provides selection for the pickup time delay, used to delay the protection
operation.
NTRL IOC DIRECTION
Range: Disabled, Forward, Reverse
Default: Disabled
This setting provides control to the Neutral IOC function in terms of permitting operation
upon fault conditions in the selected current flow direction, and blocking it when faults
occur in the opposite direction.
OUTPUT RELAY X
For details see Common
BLOCK 1 to 3
For details see Common
setpoints.
setpoints.
setpoints.
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: SETPOINTS