DET-653C EntelliGuard
®
G Circuit Breaker Application Guide
24-May-12 Section 3. EntelliGuard
®
TU Trip Unit System
©2012 General Electric All Rights Reserved
• Instantaneous selectivity between a circuit breaker with an EntelliGuard TU trip Unit and any non-current limiting circuit breaker may be evaluated via
traditional time current curve analysis or simply multiplying the upstream instantaneous trip setting by .9 which accounts for the tolerance of the line
side circuit breaker around the nominal setting. If The EntelliGuard TU's Instantaneous zone selective interlocking capability between similarly equipped
circuit breakers is employed then selectivity up to the upstream circuit breaker's full withstand or short circuit rating is possible.
The table below identifies maximum instantaneous pickup multipliers possible for various types and sizes of GE circuit
breakers. Lower part of table identifies the maximum instantaneous pickup in amperes for various circuit breaker, sensor and
rating plug combinations.
Table 3.2. Maximum Instantaneous Pickup Multipliers for GE Circuit Breakers
Line side device with Entelliguard TU Trip Unit
EntelliGuard G,
ANSI/UL Std I
EntelliGuard
G, ANSI Ext I
Frame
determines
maximum
instantaneous
pickup (X) for PB2
and WP CB.
Plug/Icw ratio
determines
maximum
possible for
EntelliGuard G
CB. EntelliGuard
values shown are
more maximum
withstand tiers.
2000A frame 15 15 15 30
2500A frame 13 N/A 15 30
4000A frame 10 10 15 23
5000A frame N/A 7 15 19
800A frame, 800A plug 12,000 12,000 12,000 24,000
1600A frame, 1600A plug 24,000 24,000 24,000 48,000
3000A frame, 3000A plug 39,000 N/A 45,000 90,000
3200A frame, 3200A plug N/A 41,600 48,000 96,000
6000A frame, 6000A plug N/A N/A 90,000 96,000
Maximum instantaneous is a multiple of rating plug, the above values may be lower if a smaller rating plug than
maximum for frame is used. In PB2 & WavePro CB maximum instantaneous multiplier is limited by frame rating. In
Entelliguard G the maximum Instantaneous X may be limited by circuit breaker withstand or short time rating (also
known as Icw).