EntelliGuard®TU Trip Unit
09/25/08 Section 1 – General Information
© 2008 General Electric All Rights Reserved 7
SECTION 1 – GENERAL INFORMATION
INTRODUCTION
The EntelliGuard TU Trip Unit is an electronic device that
interfaces with a circuit breaker. It monitors the breaker
phase currents, neutral current and/or voltage and trips
the breaker in the event of an over-current or voltage
related condition. It also provides protective relay
functions, advanced metering, diagnostic features, and
communications. The Trip Unit can be removed or
replaced in the field by de-energizing and removing the
cover of the circuit breaker.
The Trip Unit also connects with the circuit breaker flux
shifter to provide the electromechanical tripping function.
A user interface is provided on the front panel to allow
adjustment of the Trip Unit’s parameters.
ABBREVIATIONS AND ACRONYMS
The abbreviations and acronyms in Table 1 used
throughout this manual. Slightly different abbreviations
and acronyms are used for IEC trip units.
Table 1: Abbreviations and Acronyms
Item Definition
I
RMS
True RMS current measurement through a
phase
xl
CT
Multiples of current sensor rating (non-
dimensional)
l
n
Rating plug ampere setting where l
n
l
CT
. This is
the breaker nominal rated current (A)
PRODUCT DESCRIPTION
Appearance
The Trip Unit includes a graphical LCD. The front panel is
similar to those shown in Figure 1 through Figure 3.
Figure 1: Front Panel View – Power Break II and
WavePro Trip Units
Figure 2: Front Panel View – Power Break I and AKR
Trip Units
Figure 3: Front Panel View – EntelliGuard G Trip Units
LCD ACCESS
The trip unit has five function keys as shown in Figure 4.
Any key, when pressed, powers up the LCD.
All SETUP, STATUS, METER and EVENTS information is
accessed through these five keys.
To Next Page
Loading...
