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Shown charged
23.0
13.0
11.0
15.0
5.0
3.0
1.0
Magnet core
3.0
Housing
5.0
Mounting holes
7.0
Magnet coil
9.0
Magnet armature
11.0
Tension spring
13.0
Adjusting (factory-set) screw for 11.0
Figure 19: Construction of secondary shunt release
Shown charged
23.0
21.0
Locking pin
23.0
Striker pin
25.0
Latch
27.0
Spring
29.0
Lower connection terminal
A
Locked/unlocked selection screw (undervoltage release only)
Figure 20: Latch details
26
31.0
27.0
25.0
21.0
7.0
9.0
1.0
15.0
21.0
23.0
25.0
27.0
31.0
33.0
A
29.0
27.0
25.0
21.0
33.0
Tripping pin
Locking pin
Striker pin
Latch
Spring
Striker-pin spring
Terminal block
These releases are mechanical-energy storage
devices. Their internal springs are charged as
a consequence of the circuit breaker
mechanism operation. This energy is released
upon application or removal (as appropriate)
of applicable control voltages (refer to Figure
19: Construction of secondary shunt release
and Figure 20: Latch details on page 26 and
Figure 21: Undervoltage lock/operate
selection on page 27).
Secondary shunt release (optional) (54.2)
A secondary shunt release (second trip coil) is
used for electrical tripping of the circuit
breaker by protective relays or manual-control
devices when more than one trip coil is
required. The second trip coil is generally
connected to a separate auxiliary supply (dc
or ac) from the control supply used for the
normal trip coil.
Undervoltage release (optional) (54.2)
The undervoltage release is used for
continuous monitoring of the tripping-supply
voltage. If this supply voltage falls excessively,
the undervoltage release will provide for
automatic tripping of the circuit breaker.
The undervoltage device may be used for
manual or relay tripping by employing a
contact in series with an undervoltage-device
holding-coil.
Relay tripping may also be achieved by
employing a normally open contact in parallel
with the holding coil. If this scheme is used, a
resistor must be provided to limit current
when the normally open contact is closed.
Secondary and undervoltage releases
are available for all standard ANSI/IEEE control
voltages.
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