GE D90 Plus Instruction Manual page 290

GROUPED PROTECTION ELEMENTS
280
Use Seal-In
Range: Yes, No
Default: Yes
If set to "Yes," the breaker failure element is sealed-in only if current flowing through the
breaker is above the supervision pickup level.
Three Pole Initiate
Range: any FlexLogic operand or shared operand
Default: Off
This setting selects the operand that initiates three-pole tripping of the breaker when
asserted.
Block
Range: any FlexLogic operand or shared operand
Default: Off
Assertion of the operand assigned to this setting blocks operation of the breaker failure
element.
Phase Current Supervision Pickup
Range: 0.001 to 30.000 pu in steps of 0.001
Default: 1.050 pu
This setting specifies the phase current initiation and seal-in supervision level. Generally,
this setting needs to detect the lowest expected fault current on the protected breaker. It
can be set as low as necessary (lower than breaker resistor current or lower than load
current). High-set and low-set current supervision ensures correct operation.
Neutral Current Supervision Pickup
Range: 0.001 to 30.000 pu in steps of 0.001
Default: 1.050 pu
This setting specifies the neutral current initiate and seal-in supervision level. Generally,
this setting needs to detect the lowest expected fault current on the protected breaker.
Neutral current supervision is used only in the three phase scheme to provide increased
sensitivity. This setting is valid only for three-pole tripping schemes.
Use Timer 1
Range: Yes, No
Default: Yes
If this setting value is "Yes," the early path is operational.
Timer 1 Pickup Delay
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0 seconds
Timer 1 is set to the shortest time required for breaker auxiliary contact Status-1 to
open, from the time the initial trip signal is applied to the breaker trip circuit, plus a
safety margin.
Use Timer 2
Range: Yes, No
Default: Yes
If this setting value is "Yes," the main path is operational.
Timer 2 Pickup Delay
Range: 0.000 to 65.535 seconds in steps of 0.001
Default: 0 seconds
Timer 2 is set to the expected opening time of the breaker, plus a safety margin. This
safety margin was historically intended to allow for measuring and timing errors in the
breaker failure scheme equipment. In microprocessor relays this time is not significant.
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION