Current Unbalance Relay; Under Voltage Relay; Under Voltage Relay Zero-Volt Trip Enable; Over Voltage Relay - GE EntelliGuard G Application Manual

DET-653C
24-May-12

Current Unbalance Relay

This function compares the true RMS 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.
3.21).
Table 3.21. Current Unbalance Settings
Item Options
Current unbalance Adjustable from 10% to 50% in
pickup increments of 1%.
User adjustable from 1sec to 15sec in
Current unbalance
increments of 1sec. Setting this value to
delay setting
zero (0) will disable the relay.

Under Voltage Relay

This function measures the true RMS 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. Uses the same timing set
for the Under-Voltage Relay (Table. 3.22).
Table 3.22. Under Voltage Settings
Item Options
Under voltage Adjustable from 50% to 90% in
pickup increments of 1%.
User adjustable from 1sec to 15sec in
Under voltage
increments of 1sec. Setting this value
delay setting
to zero (0) will disable the relay.

Over Voltage Relay

This function measures the true RMS voltage in all phases
and initiates a trip if any phase voltage exceeds the set
point. See Table. 3.23.
Table 3.23. Over Voltage Settings
Item Options
Over voltage User adjustable from 110% to 150% in
pickup increments of 1%.
User adjustable from 1sec to 15sec in
Over voltage delay
increments of 1sec. Setting this value
setting
to zero (0) will disable the relay.

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. 3.24).
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EntelliGuard
Section 3. EntelliGuard TU Trip Unit System
Table 3.24. Power-Reversal Settings
Item Options
Power reversal User adjustable from 10 kW to 1990 kW
pickup in increments of 10 kW.
User adjustable from 1sec to 15sec in
Power reversal
increments of 1sec. Setting this value to
delay setting
zero (0) will disable the relay.

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

The Trip Unit gets its voltage input from an externally
mounted central module, called a Voltage Conditioner. The
Voltage Conditioner is wired to each trip unit in a line-up.
Voltage Conditioner Cat#: PLVC1G01

Potential Transformer Connection

Select the appropriate potential transformer connection,
either line-to-line (Ph-Ph) or line-to-neutral (Ph-N).

Power Demand Intervals

This function sets the power demand interval, which can be
in the range of 5min to 60min, in steps of 5min. This set-
point specifies the time interval for power demand
averaging. The trip unit calculates a rolling average of
breaker power over this time interval.

Current Alarm

The Trip unit provides two types of current alarm: Current
Alarm 1 and Current Alarm 2. The current alarm's ON/OFF
pickup settings are user adjustable from 0.5 to 1.0 xIn in
steps of 0.05. The trip unit does not allow the current alarm
OFF set-point to be set above the ON threshold. If the
highest measured phase current goes above the current
alarm 1 or current alarm 2 ON set-point, and then remains
above the set-point for more than 60sec, the output will
close if assigned to either of these alarms. If the current falls
below the current alarm 1 or current alarm 2 set-point for
more than 60sec, the output, if assigned to the current
alarm, will open. This is a definite time function with a 60s
delay and a 60sec cool down period. Both periods are fixed.

Trip Logic Inputs

The trip unit is able to receive two hardwired input signals.
Either can be a 24Vac or Vdc signal. The inputs can be
assigned to three main functions:
• Reduced Let Through Energy "RELT" instantaneous
protection "ON".
• Breaker "Trip"
• Breaker "RESET"
® G Circuit Breaker Application Guide
31