Eaton Magnum PXR, Руководство пользователя

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User Manual MN013016EN
Effective July 2022
Magnum PXR and Power Defense SB low
voltage power circuit breakers user manual
EATON www.eaton.com
Operating mechanism
The Magnum PXR and PD-SB operating mechanism is based on
the proven cam and spring design of the Magnum DS power circuit
breaker . It is easily accessed by removing four cover screws and the
front cover ( Figure 24 ) . The mechanism is a two-step stored energy
mechanism . Potential energy is stored to close the circuit breaker .
Sufficient energy to open the circuit breaker remains available after
a closing operation .
Manual operation
On manually operated circuit breakers, the closing spring can only
be charged manually . To manually charge the spring, insert one finger
in the recess behind the charging handle and pull out . This permits
a gloved hand to grasp the handle and begin charging (
Figure 25
) .
It takes from 5 to 7 downward strokes on the charging handle to
complete the manual charging process . It is possible to manually
recharge the spring immediately after closing the circuit breaker
and before it has been tripped open .
Standard manually operated circuit breakers are closed and opened
by hand using the Manual CLOSE and Manual OPEN buttons
respectively located on the front of the circuit breaker ( Figure
18
) . Performing either operation is accomplished by pressing and
releasing the appropriate button . Access to these pushbuttons can
be limited by the use of an optional, padlockable cover . In addition,
complete access to the CLOSE button can be prevented with an
optional prevent close cover . The status of the springs and the
primary contacts are always indicated in an indicator window just
above the pushbuttons .
Electrically operated optional devices are available to automatically
close or trip a manually operated circuit breaker . An electrical spring
release is available to close a manually operated circuit breaker .
Two optional devices, a shunt trip, and an undervoltage release,
are available to automatically trip (open) a manually operated circuit
breaker . All of these UL Listed optional devices can be installed
easily in the field . For more details on these devices, refer to
page 26 , “Accessory devices” in this manual .
An electrical operator, which is used to charge the closing spring
automatically, can be added to a manually operated circuit breaker
in the field ( Figure 26 ) .
Figure 24. Typical electrically operated drawout circuit breaker
with front cover removed
Figure 25. Circuit breaker closing springs being
manually charged (Magnum DS shown)
b
f
h
a
Secondary wiring points
b
Field installable accessories
(three maximum)
c
Trip unit
d
Electric charging motor
e
Manual charge handle
f
Operations counter (optional)
g
Padlockable levering device access door
h
Breaker position indicator
g
e
d
c
a