GE EntelliGuard G Application Manual page 11
Power circuit breaker
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Also See for EntelliGuard G:
- Installation, operation and maintenance manual (252 pages) ,
- Application manual (94 pages) ,
- Instructions manual (10 pages)
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Section 3. EntelliGuard TU Trip Unit System
Note: These incident energy calculations do not take
into account motor contribution or other factors that
may affect expected levels of incident energy or
hazard. For a thorough understanding of the incident
energy available or HRC in a power distribution system,
an Arc Flash Study should be conducted by engineer-
ing personnel qualified to provide such analysis.
Above Other Power Circuit Breakers
Using the EntelliGuard TU trip unit's unique
Instantaneous Zone Selective Interlocking (ZSI), the
main circuit breaker also can be set to interrupt
selectively for faults in its zone of protection.
However, the pick up level must be nested to prevent
a nuisance trip at the main. Allowing for a 10%
tolerance in the pick up current of both trips, the
upper boundary of the main's trip may be estimated
at approximately 11kA. Again, Figure 3.1 shows that
available fault currents above 25kA will generally
produce arcing currents above 11kA. Table 3.1 shows
that, in a system with fault currents from 25kA to
90kA, the feeder and main circuit breaker will provide
protection at HRC1 or HRC2 selectively. To this
capability one can add the RELT setting that provides
more sensitive and faster protection when needed.
Table 3.1
GE Molded Case Circuit
Breaker Family
FB, FC, TEY & THQL
TED, TEC
TF, TJ, TK
Spectra E, F & G Frame
Spectra K Frame
Spectra with MVT, G & K Frame AE-GP
Record Plus G Frame
Record Plus E Frame
Power Break with MVT
Instantaneous Clearing Time
RELT Clearing Time
1 TM = Thermal Magnetic
E
= Electronic
AE = Adjustable Electronic
LP
= Lighting Panel Application
GP = General Purpose Application
MCP = Motor Circuit Protection Application
Courtesy of NationalSwitchgear.com
Minimum
Circuit
EntelliGuard TU
1
Breaker Type
Short Time Band
TM-LP
0.025
TM-GP & MCP 0.025
TM-GP
0.025
E-GP
0.025
E-GP
0.033
0.025
E & AE-GP
0.042
E-GP
0.033
AE-GP
0.058
Flexibility
The EntelliGuard TU was designed with solution
flexibility from the start. Examples of this flexibility
can be seen in some of its key capabilities and
characteristics, including:
• Availability to choose two different industry-rec-
ognized open protocols – Modbus RTU or Profibus
DP – that almost any building management,
power management or process software can
use. No closed protocols, no proprietary soft-
ware, only flexibility to create the right solution
for each system's needs.
• The industry's only universal spare trip unit (patent
pending). An EntelliGuard TU Universal Spare Trip
Unit can be installed in any EntelliGuard G circuit
breaker, regardless of frame size, sensor size,
short circuit rating or even if the circuit breaker
is a UL, ANSI or IEC model. Upon powering of the
trip unit, it automatically knows in what circuit
breaker it is installed and automatically acquires
that device's personality.
• The industry's only universal trip rating plug. Any
rating plug can be installed in any circuit breaker
within the acceptable sensor range. In other words,
for a specific rating, only one plug is necessary,
480V, in box, 32mm HRC @ lbf=
Clearing
Time
35kA 42kA 50kA 60kA 75kA 90kA
0.080
2
2
2
2
0.080
2
2
2
2
0.080
2
2
2
2
0.080
2
2
2
2
0.088
2
2
2
3
0.080
2
2
2
2
0.097
2
2
3
3
0.088
2
2
2
3
0.113
2
3
3
3
0.050
1
2
2
2
0.042
1
2
2
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
2
2
2
9
- Quick Links:
- Entelliguard Tu Trip Unit System
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