Speedfax 2017

Molded Case Circuit Breakers
Digital Solid State Sentron Sensitrip IV Series
Revised on 05/31/18
Technical
The Sentron Sensitrip IV
circuit breaker is a true RMS
current sensing device. Digital
microprocessor circuitry within the
electronic trip unit provides more
precise control over the circuit
breaker functions. This control
allows circuit coordination flexibility
not available with thermal magnetic
circuit breakers.
Functions available in Sentron Sensitrip circuit breakers
Catalog
Number
Suffix
Trip
Type
Cont
Current
Setting
Long
Time
Delay
LI LI u u u
Instantaneous
Pickup
Short
Time
Pickup
Short
Time
Fixed
Delay
Short
Time
I2t
Delay
Ground
Fault
Pickup
LIG LIG u u u u u
LSI LSI u u u u u u
LSIG LSIG u u u u u u u u
Ground
Fault
Delay
Typical Trip Unit Labeling and Adjustment Positions for the Sentron Sensitrip Circuit Breaker.
LI Trip Units a
LIG Trip Units a
LSI Trip Units a
7
LSIG Trip Units a
MOLDED CASE
CIRCUIT BREAKERS
l n
l r
= Maximum circuit breaker ampere rating
= Continuous current rating expressed in amperes
I i = Instantaneous pickup expressed in amperes
I sd = Short time pickup expressed in multiples of I r
I g = Ground fault pickup expressed in amperes
t sd = Short time delay - either fixed or I 2 t time delay function
t ld = Long time delay - I 2 t time delay function
t g = Ground fault delay - I 2 t time delay function
NOTE: Frame rating (In) of 600A shown as an example.
Trip unit settings will vary based on the specific frame
rating (In) of the device.
a Schematic of advanced trip unit shown. Basic trip units
are identical but do not include DAS / Maintenance
Mode functionality.
Siemens Industry, Inc. SPEEDFAX Product Catalog 7-147