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The capacitors which allow circuit-breaker operation, for a maximum time of about 30 seconds (with
closed circuit-breaker), even in the case of a drop in the auxiliary voltage, are provided in the control
circuit. In case of emergency, the circuit-breaker can in any case be opened by means of a special
crank handle which acts directly on the moving armature of the drive.
Compared to a traditional operating mechanism, the magnetic actuator has few moving parts and
greatly reduced wear even after a high number of closing and opening cycles.
These characteristics therefore make it practically maintenance-free.
7.1.2. Opening and closing operations
The opening and closing operations can either be remotely controlled by means of the special
inputs provided in the control module, or locally by pressing the pushbuttons on the control panel (7)
(fig. 4).
During the operations, the moving armature of the actuator acts directly on the moving contact by
means of the kinematics (8-9-10) (fig. 7).
7.1.3. Reclosing function
Thanks to the short duration of capacitor recharging, the drive is suitable for multiple reclosing
operations with O-0.3s-CO-15s-CO cycle.
7.1.4. Control module functions
All the conditions for controlling the opening and closing commands given to the magnetic actua-
tor are managed by a microprocessor:
• The power supply voltage must be applied to the AC/DC converter.
• The capacitor must be sufficiently charged for the next operation:
Circuit-breaker position
Open
Closed
Magnetic latching in end-of-run position.
Magnetic latching and action of the magnetic field of a coil.
Moving armature in opposing position and magnetic end-of-run latching.
• The closing coil can only be activated when the circuit-breaker is open
• The opening coil can only be activated when the circuit-breaker is closed
• Closing is disabled when an opening command is active at the same time
• De-activation of the opening or closing coil takes place when the relative limit position has been
reached.
• WRONG POSITION (auto trip) function: if the final CLOSED (or OPEN) position is not reached
within 70 ms during a closing (or opening) operation, an opening operation is immediately started
to guarantee reaching a defined safe position in any case.
• The anti-pumping function ensures that only one closing-opening cycle is carried out when a
closing command followed by an opening command is active. The active closing command must
be cancelled and reset for the next closing operation.
• Activation of the input for the closing command can be locked by means of an external locking
signal.
• The input for the "lock on closing" command must be energised to be able to close the circuit-
breaker (without power it inhibits closing).
Operations
Closes and Opens
Opens
13
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