GE Industrial Solutions EntelliGuard TU Conversion kits - Manual (Page 2)

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Introduction
GE conversion kits are designed to upgrade existing GE Low Voltage Power Circuit Breakers, rather
then replacing the entire breaker. The conversion kits contain enhanced solid state Entelliguard  TU,
representing the latest technological advancements in GE trip systems.
This supplementary publication covers specific instructions for the installation of Entelliguard  TU
with advanced optional features like RELT (Reduced energy let through mode), Ground Fault Alarm
etc. in GE Low Voltage Power Circuit Breakers. This supplementary publication does not detail all
aspects of the conversion kit installation process.
The EntelliGuard TU trip unit provides an optional second, user-adjustable, RELT Instantaneous trip.
This trip provides an alternate Instantaneous setting that allows a user to temporarily set a circuit
breaker to a more sensitive pickup to provide better protection, only when better protection is
needed and some selectivity may be sacrificed.
RELT Instantaneous pickup can be enabled via application of 24Vdc or Vac at the RELT input
terminals or serial communications via the Modbus communication port. The RELT input command
may be wired to a manual switch, automatic sensor or, via external logic, to one or more signal
sources. When the EntelliGuard TU trip unit has the RELT Instantaneous pickup enabled, the trip unit
provides a feedback signal via an optically isolated dry contact and serial communication. This
provides positive feedback that the trip unit has received and reacted to the RELT Enable command.
RELT harness consists of four wires for this input and output signal
The EntelliGuard TU trip unit’s RELT capability provides the ultimate in user flexibility for wiring and
controlling an alternate Instantaneous setting for temporary use to reduce personnel hazard.
The RELT switch may be connected to a manually operated two-position switch, a remote sensor, or
both simultaneously. The EntelliGuard TU trip unit provides a feedback capability directly from the
trip so the user is able to verify that the signal was received by the trip unit and the settings have
changed. Optionally, an indicating light may also be connected to the source of control power so the
user knows if control power is available to change the setting. The trip unit does not require its own
control power to accept a RELT input and change the Instantaneous trip pickup according to the user
settings. However, if control power is available to the trip unit, the feedback signal will function
immediately, rather than when the trip unit becomes self-powered through its load current (Fig. 1).