GE Industrial Solutions EntelliGuard TU Trip Units - Manual (Page 26)

EntelliGuard TU Trip Units: UL/ANSI Models DEH-4567B
Protection
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Instantaneous ZSI is either enabled or disabled. There are
no settings to modify the action of Inst ZSI.
INST ZSI timing is as follows::
• EntelliGuard G (ANSI and UL489): An additional 2.5
cycles (ignore inst for 3 cycles after seeing input and trip
on the 7
th half cycle)
• AKR, WavePro and Conversion Kits: An additional 4
cycles (ignore inst for 4.5 cycles after seeing input and
trip on the 9
th half cycle.)
INTERRUPTION PROTECTION
Making Current Release (MCR)
Every EntelliGuard G circuit breaker uses a making current
release. The making current release varies per circuit
breaker Envelope and is related to the circuit breaker’s
close and latch rating.
The MCR pickup is activated at the time the circuit breaker
closes and for six cycles thereafter. When the six cycles are
over, the threshold changes to the HSIOC pickup setting.
High Set Instantaneous Protection (HSIOC)
HSIOC is also known as Override Pickup. Some of the trip
units on EntelliGuard G circuit breakers may be provided
with an override instantaneous trip.
Whether such a trip is provided or not depends on the
circuit breaker within which the trip is installed. If the circuit
breaker’s withstand lcw is equal to the short circuit rating
then the trip will not have an override pickup. If the
withstand rating is lower than the short circuit rating then
the trip will enable override protection of the circuit breaker
at the short time withstand rating level.
In UL 489 circuit breakers the HSIOC setting is nominally at
107% of the Icw for the circuit breaker. Taking tolerance
into account, the override’s minimum trip is at 100% of the
circuit breaker’s Icw.
In UL 1066 (ANSI) circuit breakers the HSIOC setting is also
at 107% Icw if the adjustable selective instantaneous is ON.
If the adjustable selective instantaneous is OFF then the
HSIOC nominal pick up is at 98% of the circuit breaker’s Icw
and, considering tolerance, the minimum pickup is at 91%
of the circuit breaker’s Icw.
Power Break I, WavePro and AKR circuit breakers do not
employ an override function. Power Break II circuit
breakers use a mechanical override function.
Breaker Interface Module (BIM)
The EntelliGuard G Breaker uses a Breaker Interface
Module which is internally connected to the EntelliGuard G
Trip Unit. This allows the breaker to electronically reject an
incorrect trip unit being inserted into a breaker, instead of
the traditional mechanical rejection methodology used on
other GE circuit breakers.
The BIM contains information that describes the breaker
configuration to the trip unit. The trip unit extracts
information on Sensor Rating, Interruption Rating, and pole
configuration from the BIM. This is a one-time event that
occurs when a new trip unit is first powered up in a
breaker. Every time the trip unit powers up in the breaker
from that point forward, it compares information in the BIM
to the information it initially read and stored. If the
information does not match the trip unit will immediately
trip the breaker and set a BIM Error Flag, and record a BIM
error trip event. In effect, the trip unit “marries” the breaker.
NOTICE
SOFTWARE REVISION 08.00.23 AND GREATER:
If a BIM read fails the trip unit will not open the breaker,
instead it will modify its internal configuration to match the
AIC rating of the least capable breaker in the family. The
trip unit will periodically read the BIM after that, and on a
successful match the original settings will be restored.
While the BIM error persists a BIM Err message will be
displayed on the LCD.
The “Universal Trip Unit” can be used as a replacement for
any trip unit. The Protection and Advanced Features of the
Universal trip unit should match the configuration of the
trip unit being replaced to maintain the same functionality.
The Universal trip unit is programmed with minimum
values for all protection, and it will automatically read the
BIM values from the first breaker it is installed in. This will
force the Universal Trip Unit to assume the configuration of
the trip unit it is replacing. Once this process is complete,
the Universal Trip Unit cannot be moved to another
breaker – it “marries” the breaker.
BIM Transaction Details
On power up the trip unit immediately queries the BIM for
local breaker configuration information.
If the GTU’s internally stored BIM ID (Breaker Serial
Number) is ZERO:
• Upon power-up the trip unit reads BIM ID
• Since there is no match:
o GTU uses Default Breaker Configuration Data for
protection for approximately 200 msec
o GTU fetches BIM Data and uploads it into GTU
non-volatile memory.
o GTU continues normal operation