Section 1: introduction
1-1 GENERAL INFORMATION
Type DSII and DSLII Power Circuit Breakers are horizontal dra-
wout magnetic air circuit breakers utilizing an electronic tripping
system. They are designed for use in metal enclosed switchgear
assemblies having maximum voltages of 635 volts AC for Type
DSII breakers and 600 volts AC for Type DSLII breakers. Depend-
ing on the specific breaker being considered, DSII and DSLII
breakers are available in frame sizes from 800 through 5000
amperes with interrupting ratings as high as 85,000 amperes
rms symmetrical for Type DSII and 200,000 amperes rms sym-
metrical for Type DSLII breakers. (Figure 1-1, Tables 1.1 and 1.2).
The breaker nameplate provides complete rating information
and all DSII breakers conform to applicable NEMA, ANSI and
IEEE standards (Figure 1-2).
Each DSII and DSLII breaker consists of a basic breaker as-
sembly, three interrupter assemblies (arc chutes), barriers and
an electronic trip unit. DSLII breakers have integrally mounted,
series connected current limiters. The purpose of the current
limiters is to extend the interrupting rating of the standard DSII
breaker (Figure 1-3).
The Type DSII breaker is a four position drawout (Connect, Test,
Disconnect and Remove) design supplied with either a manually
or electrically operated, two-step stored energy mechanism.
This type of mechanism assures positive control at the instant
of closing the main contacts.
Controls and indicators are functionally grouped on the front of
the breaker. The faceplate, in conjunction with a closed breaker
compartment door, provides a double steel safety barrier.
DSII breakers can be withdrawn on extension rails for inspec-
tion, minor maintenance or a visual inspection of the inside
of the breaker compartment. The captive extension rails are a
permanent part of the breaker compartment (Figure 1-4).
NOTICE
PLEASE READ AND UNDERSTAND THESE INSTRUCTIONS BEFORE
ATTEMPTING TO UNPACk, OPERATE OR MAINTAIN THIS EQUIPMENT.
STUDY THE BREAkER AND ITS MECHANISM CAREFULLY BEFORE AT-
TEMPTING TO OPERATE IT ON AN ENERGIZED CIRCUIT.
DSII-632
DSII-840
DSII-308
Figure 1-1 Type DSII Circuit Breaker Family
Effective July 2010
Instructional Book
IB694C694-03
7
eaton corporation
www.eaton.com
