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7. Operation of the switchgear
WARNING
For ENA version: do not access the area behind or
alongside the switchgear when it is energised or
being energised.
The basic element of UniGear 500R is the
incoming/feeder unit with Vmax circuit-breaker in
series with a three position“off-load” disconnector
(chapter 4.4).
The circuit-breaker is always mechanically interlocked
with the three-position disconnector to prevent
dangerous or inadvertent operations.
In addition to this unit, the switchgear can be provided
with an additional unit (Bus-section), equipped with
two threeposition disconnectors identical to that of the
incoming/ feeder unit.
Besides transferring the load, they allow the earthing
of right or left busbars, but not in contemporary. If it is
needed to connect both busbars to earth, then one
busbar must be fitted with dedicated earthing switch
on the top of the switchgear (chapter 4.6).
7.1 Circuit-breaker operation
For more detailed information, please refer to the
Vmax installation and service manual n° 1VCD600189.
The circuit-breaker can be operated both manually
and electrically according to the installation
requirements. To prevent inadvertent removal of a
circuit earth applied through the circuit-breaker,
electrical tripping of the breaker is disabled when the
three-position disconnector is in the EARTH position.
To remove the earth, the circuit-breaker must
therefore be tripped using the manual trip facility. A
padlock can be fitted onto the manual trip push button
to prevent unauthorised removal of the earth.
a) Manual spring charging
To manually charge the closing spring, operate the
charging lever 5 (Figure 88) until the relevant
indicator 4 changes its status. The normal force to be
applied to the charging lever is lower than 200 N.
b) Electrical spring charging
On request, the circuit-breaker can be supplied with a
geared motor for automatic spring charging. The
geared motor automatically charges the springs after
any operation until the relevant indicator (Figure 88)
changes its status.
Should the power fail while charging, the geared
motor stops and automatically restarts spring charging
when the power is restored. In any case, spring
charging can be manually completed. If power is
restored during manual charging, the manual lever is
disconnected ensuring operator safety.
c) Circuit-breaker closing
The operation can only be performed when the closing
springs are fully charged. For manual closing, remove
the padlock (if fitted) from the closing button of the
circuit-breaker (Figure 89) and push the button (Figure
88). With a shunt closing release (optional), the
operation can be carried out remotely by means of a
special control circuit.
Final closing is signalled by the relative indicator
(Figure 88). A padlock can be fitted onto the closing
button to prevent unintentional operation (Figure 89).
d) Circuit-breaker opening
For manual opening, remove the padlock (if fitted)
from the opening button of the circuit-breaker (Figure
89) and push the button (Figure 88). With a shunt
opening release (optional), the operation can be
carried out remotely; this function is, in any case,
disabled if the three-position disconnector is in the
EARTH position.
Final opening is signalled by the relative indicator
(Figure 88). A padlock can be fitted onto the opening
button to prevent unintentional operation.
Figure 88: Circuit-breaker operation.
1 Closing push button
2 Opening push button
3 Indicator for circuit-breaker opening closing
4 Indicator for springs charged or discharged
5 Lever to manually charge operating springs
6 Operation counter
Figure 89: Locked closing button.
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