Standard And Optional Devices; 3-10.1 Motor Cut-Off Switch (Ls); 3-10.2 Spring Release Device (Srd); 3-10.3 Anti-Pump Relay (Y) - Eaton DSII Series Instructions For Installation, Operation And Maintenance

Instructional Book IB694C694-03
Motor Cut-off
Switch
Compartment
Trip Lever
Figure 3-14 Type DSII Circuit Breaker (Bottom View)
The secondary connection of a drawout circuit breaker is
provided by contact blocks mounted on the rear upper frame
of the circuit breaker. They are mounted, as required, in two
rows of two blocks per row. Each block consists of 12 spring
loaded contacts. Protective covers over the top row of con-
tacts help to protect from damage (Figures 3-1 and 3-2).

3-10 Standard and Optional Devices

3-10.1 Motor Cut-Off Switch (LS)

The motor cut-off switch is standard on all power operated
breakers. It disconnects the motor when the closing springs
are fully charged, and is operated by the motor cut-off switch
lever on the operating mechanism (Figure 3-14).

3-10.2 Spring Release Device (SRD)

The spring release device is standard on power operated
breakers and optional on manually operated breakers. It
permits a breaker to be closed electrically. A close signal
is applied to the spring release device to begin the closing
operation. The spring release coil is energized through the
anti-pump relay, the motor cut-off switch, and a normally
closed "b" auxiliary switch contact, which operates the
spring release latch to release the closing springs.
Ground
Contact
Interference
Interlock
Figure 3-15 Anti-Pump Relay Shown Unmounted

3-10.3 Anti-Pump Relay (Y)

Power operated breakers have an anti-pump relay mounted
in the upper left front portion of the breaker just behind the
faceplate. It disconnects the spring release device after the
breaker has been closed (Figure 3-15). This prevents the
breaker from trying to close immediately after being tripped
open (pumping) on concurrent close and trip signals.

3-10.4 Shunt Trip Attachment (STA)

The shunt trip attachment is standard on power operated
breakers and optional on manually operated breakers (Figure
3-16). It is an electromechanical device of the clapper type.
A trip signal to the shunt trip device energizes a coil which
causes its armature to be attracted to the core. The armature
pushes the trip lever on the breaker trip shaft, causing the
breaker to trip. As the breaker trips, a normally open "a" aux-
iliary switch contact in series with the shunt trip attachment
coil de-energizes the coil.
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Effective July 2010
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