GE EntelliGuard TU - Section 1 - General Information; Protective Relay Functions

EntelliGuard®TU Trip Unit
Section 1 – General Information 09/25/08
12 © 2008 General Electric All Rights Reserved
PROTECTIVE RELAY
The protection relay can be set to either cause a trip or
an alarm. If the PR Enable on the LCD is set to ON, a trip
will be generated, if set to NO an alarm will be generated.
Voltage Unbalance Relay
This function compares the highest or lowest phase
voltage with the average of all three phases and initiates
a trip if the difference exceeds the set point.
Table 9: Voltage Unbalance Settings
Item Option
Voltage unbalance
pickup
Adjustable from 10% to 50%
in increments of 1%.
Voltage unbalance
delay setting
Adjustable from 1 sec to
15 sec in increments of 1 sec.
Setting this value to zero (0)
disables this function.
Current Unbalance Relay
This function compares the current in the highest or
lowest phase with the average of all three phases and
initiates a trip if the difference exceeds the set point.
Table 10: Current Unbalance Settings
Item Option
Current unbalance
pickup
Adjustable from 10% to 50%
in increments of 1%.
Current unbalance
delay setting
Adjustable from 1 sec to
15 sec in increments of 1 sec.
Setting this value to zero (0)
disables this function.
Under Voltage Relay
This function measures the voltage in all phases and
initiates a trip if any phase voltage drops below the set
point.
Under Voltage Relay Zero-Volt Trip Enable
This function determines if the relay trips when all three-
phase voltages drop to zero volts. See Table 11.
Table 11: Under Voltage Settings
Item Option
Under voltage
pickup
Adjustable from 50% to 90% in
increments of 1%.
Under voltage
delay setting:
Adjustable from 1 sec to 15 sec in
increments of 1 sec. Setting this value
to zero (0) disables this function.
Over Voltage Relay
This function measures the voltage in all phases and
initiates a trip if any phase voltage exceeds the set point.
See Table 12.
Table 12: Over Voltage Settings
Item Option
Over voltage
pickup
Adjustable from 110% to 150% in
increments of 1%.
Over voltage
delay
Adjustable from 1 sec to 15 sec in
increments of 1 sec. Setting this value
to zero (0) disables this function.
Power-Reversal Relay
This function measures the direction of power flow
through the breaker and initiates a trip if a sufficient
magnitude of reverse power is detected.
Table 13: Power Reversal Settings
Item Option
Power
reversal
pickup
Adjustable from 10 kW to 990 kW in
increments of 10 kW.
Power
reversal delay
Adjustable from 1 sec to 15 sec in
increments of 1 sec. Setting this value
to zero (0) will disable this function.
Power Direction Setup
This function selects the normal power flow direction for
the breaker, either from line to load or from load to line.
This direction setup also affects the sign of the normal
power metering displays.
Potential Transformer Primary Voltage
Enter the primary voltage rating of the potential
transformer. The range of values is 120 V to 600 V, with
an increment of 1 V.
NOTICE
Incorrect set point will result in incorrect metering
values.
Potential Transformer Connection
Select the appropriate potential transformer connection,
either line-to-line (Ph-Ph) or line-to-neutral (Ph-N).