GE EntelliGuard G Application Manual page 18

Section 3. EntelliGuard TU Trip Unit System
• High Set Instantaneous Overcurrent Trip: Provided
on Power Break II and some EntelliGuard G
circuit breakers.
• Making Current Release (MCR): Provided on all
EntelliGuard G circuit breakers.
• Reduced Energy Let-Through Instantaneous Trip:
An available option on Power Break II, WavePro,
AKR and EntelliGuard G circuit breakers.
Each of these Instantaneous trips provides optimum
protection, selectivity or both as required for different
applications, subject to the capabilities of the
respective circuit breakers in which the trip units
are installed.
Adjustable Selective Instantaneous
The EntelliGuard TU uses an exclusive algorithm,
developed by GE, to recognize the wave shape of
fault current within a cycle. With the improved
analysis of the fault current wave shape, the trip
unit allows the circuit breaker to trip immediately
yet provide superior selectivity when used above
current limiting circuit breakers or fuses. In many
cases, the trip unit's Instantaneous pick up may
be set quite low yet allow for complete selectivity
up to the circuit breaker's full withstand level. For
Table 3.7
Maximum Adjustable Instantaneous Pick-up for EntelliGuard G CBs with Normal or Extended Range Option
"In" (Plug 42
Rating, A)
Normal Extended
Range Range
150-2,000 15 N/A
2,200 N/A N/A
2,400 N/A N/A
2,500 N/A N/A
3,000 N/A N/A
3,200 N/A N/A
3,600 N/A N/A
4,000 N/A N/A
5,000 N/A N/A
6,000 N/A N/A
Extended Rating only availble in ANSI/UL1066 EntelliGuard G CB.
6,000A Sensor only available in UL489 CB.
42 & 50kA Withstand Tiers only available in UL489 CB.
16
Courtesy of NationalSwitchgear.com
Withstand Rating
50 65
Normal Extended Normal Extended
Range Range Range Range
15 N/A 15 30
15 N/A 15 28
15 N/A 15 25
15 N/A 15 24
15 N/A 15 20
N/A N/A 15 19
N/A N/A 15 17
N/A N/A 15 15
N/A N/A N/A N/A
N/A N/A N/A N/A
a list of possible selective combinations of GE cir-
cuit breakers employing the EntelliGuard TU trip
unit and various downstream overcurrent devices
see GE publication DET-536.
The EntelliGuard TU trip unit can be furnished with
one of two Instantaneous adjustment ranges. The
standard adjustable range may be as high as 15X
the trip plug value on all UL 891 or UL 1066 circuit
breakers. An optional Extended Range Adjustable
Selective Instantaneous, as high as 30X, may be
provided for UL 1066 Listed Low Voltage Power
Circuit Breakers (LVPCBs). LVPCBs also allow for
this adjustable Instantaneous trip to be turned off.
The minimum adjustable Instantaneous pick up
setting for all circuit breakers is 2X the trip plug
rating. The available maximum pickup settings are
described in Table 3.7. The maximum Instantaneous
pick up is limited by the circuit breaker's withstand
rating.
The Adjustable Selective Instantaneous will clear a
fault in 3 cycles when used in 60 Hz or 50 Hz
applications. Zone Selective Interlocking (ZSI) may
be used with this Instantaneous function, allowing
several breakers with overlapping Instantaneous
85 100
Normal Extended Normal
Range Range Range
15 30 15
15 30 15
15 30 15
15 30 15
15 26 15
15 25 15
15 22 15
15 20 15
15 16 15
13 N/A N/A
Extended
Range
30
30
30
30
30
29
26
23
19
N/A