EntelliGuard®TU Trip Unit
09/25/08 Section 3 – Operation
© 2008 General Electric All Rights Reserved 21
SETUP MODE
SETUP Mode programming must be performed with the
rating plug installed.
These procedures apply to all trip units.
SETUP procedures should only be repeated if the trip unit
or the protection characteristics are changed, requiring
different set points and time-delays.
All trip units provide long time over current protection,
long time delay, and some form of instantaneous over
current protection when installed in circuit breakers. All
other functions are optional.
If a specific set of trip unit functions, such as relaying or
short time over-current protection, has not been ordered,
that function will not appear on the trip unit display.
Ignore setup mode instructions for such functions. The
trip unit must be provided with control power during
SETUP. Power can come from internal battery power,
from an external +24 VDC power supply, or by energizing
the breaker to at least 20% of its sensor load.
• Press UP or DOWN until the SETUP mode is selected.
• Press RIGHT or LEFT to access the functions in the
SETUP mode.
• Press ENTER to save desired values.
• Press RIGHT to advance to the next function.
Entering Setpoints into Memory
1. Press UP or DOWN to select SETUP.
2. Press LEFT to select the desired protection to change.
3. Press UP or DOWN to change values. The values will
start flashing.
4. Press ENTER to store the value into the memory. The
displayed value stops flashing and the save icon
appears on the top of the LCD. This indicates that the
value has been stored in memory and is active.
5. Confirm settings on the trip unit after making
changes by exiting and re-entering SETUP mode and
rechecking each changed setting.
Long Time Pickup
The first SETUP mode display is always the Long Time
Pickup setpoint. This setpoint establishes the breaker's
nominal ampere rating, xLT, as a fraction of the rating
plug value, xIn (xLT = LT multiplier x xIn).
The Long Time Pickup settings are 0.50 to 1.00 times xIn
in steps of 0.05. The pickup value tolerance band is -10%
to +10% of the set point. An additional accuracy
degradation of ±5% is allowed for waveforms with
significant harmonic distortion.
Long Time Delay
The EntelliGuard trip unit offers up to 44 long time delay
bands. Twenty-two have steep fuse-like shape and 22
have a logarithmic curve to a straight I
2
T slope shape.
This second shape is similar to that of the thermal
element of a thermal magnetic circuit breaker.
EntelliGuard G circuit breakers use all 44 bands. WavePro,
AKR and both PowerBreak devices use the lower 19 of the
curved thermal-type bands. To see the bands and the
range of settings, see the TCCs in the Application Guide
available at wwwgeelectrical.com/industrial.
Short Time Pickup
The Short Time Pickup function establishes the current at
which short time trip is activated. Short Time Pickup is
coupled with Long Time Pickup and the choices of pickup
settings are from 1.5 to 12.0 times the long time setting,
xLT, in steps of 0.5 xLT.
The ST pickup value tolerance band is -10% to +10% of
the set point. An additional accuracy degradation of ±5%
shall be allowed for waveforms with significant harmonic
distortion
Short Time Delay
The Short Time Delay function consists of both a slope
setting and a fixed delay band setting. The slope and
delay are independently selectable. The slope setting
consists of three I
2
T slopes (1, 2, 3) and fixed delay. The
fixed delay bands consist of 15 constant time bands
Reduced Instantaneous Let-Through Instantaneous
Protection (RELT)
The EntelliGuard TU Trip Unit provides a second user
settable and user-selectable instantaneous protection
algorithm. This protection is referred to as the RELT
pickup.
This protection enables an instantaneous protection
mode that may be set separately from the “Adjustable
Selective Instantaneous” and is a bit faster. The RELT
instantaneous pickup may be set by the user to a value
from 1.5X trip rating plug up to 15X trip rating plug in
some circuit breakers.
The user may also enable the function “ON” or “OFF” at
the HMI, as well as set it to remote. In the “remote” mode
the trip unit is able to receive a command via serial
communication (Modbus or Profibus) or a hardwired 24 V
AC or DC signal to enable the RELT protection on. If the
RELT protection is ON via any of the three ways it must be
turned off that same way.
When the trip unit receives a RELT on signal the RELT
instantaneous setting is enabled. If the RELT pick up
setting is lower than the adjustable selective
instantaneous setting the RELT setting will take
precedence.
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