O P E R A T I O N
57
4.1.3.2 Operation of the three position
disconnector (motor operated
mechanism)
The motor-operated three position disconnector
operating mechanism is in principle identical to
the manual mechanism, but additionally has a
drive motor. The three position disconnector can
thus be operated by the motor, or also manually
as an alternative.
The three position disconnector is mechanically
blocked when the circuit breaker is closed. Operation
of the earthing switch is only possible when the
disconnector is open, and vice versa.
Motor operation
Motor operation of the three position disconnector
is possible when electrical controls (e.g. the operator
controls of a control unit) are fitted on the panel.
Operate the corresponding controls to switch the
three position disconnector on and off. The switch
position is indicated on the display of the control
unit and mechanically on the operating mechanisms.
Manual operation
Operation of the disconnector
•
Turn the selector lever (4 in Fig. 4.1.3.1.3)
counterclockwise and hold it fast.
•
Insert the operating lever through the released
opening (5) onto the splined shaft.
Disconnector OFF
ON
•
Turn the operating lever clockwise until the stop
is reached. (< 70°).
•
Withdraw the operating lever.
•
Turn the selector lever into the vertical position
without using force.
Disconnector ON
OFF
•
Turn the operating lever counterclockwise until
the stop is reached (< 70°).
•
Withdraw the operating lever.
•
Turn the selector lever into the vertical position
without using force.
Operation of the earthing switch
•
Turn the selector lever (4 in Fig. 4.1.2.1.3)
clockwise and hold it fast.
•
Insert the operating lever through the released
opening (7) onto the hexagon.
Earthing switch OFF
ON
•
Turn the operating lever clockwise until the stop
is reached (< 70°).
•
Withdraw the operating lever.
•
Turn the selector lever into the vertical position
without using force.
Earthing switch ON
OFF
•
Turn the operating lever counterclockwise until
the stop is reached (< 70°).
•
Withdraw the operating lever.
•
Turn the selector lever into the vertical position
without using force.
4.1.3.3 Emergency operation of the three position
disconnector (motor operated mechanism)
If the mechanism motor becomes defective or the
auxiliary power fails when the three position
disconnector is in an intermediate position, manual
operation is only possible by performing work on
the operating mechanism. This work may only be
performed by qualified personnel. In such a case,
please inform ABB Service Department.
If the three position disconnector is not in an
intermediate position on failure of the auxiliary
voltage, the operating mechanism can still be
operated as described in 4.1.3.1 even without the
auxiliary power. When blocking magnets are used
for the selector lever, the mechanism can only be
deblocked by qualified personnel. In such a case,
please contact the ABB Service Department.
4.3 Gas monitoring with gas density manometer
The high-voltage compartments must have
sufficient gas pressure during operation. (Please
consult the table entitled “Technical data” in section
10 for the pressure levels.) The insulating gas
pressure is monitored during operation by gas
density manometer (temperature- compensated).
If the gas pressure falls below the alarm level, a
signal to top up the insulating gas is issued. The
signal appears at a warning lamp (Fig.4.3.1) in the
operator control area, or on a panel control unit.
When systems are isolated for a relatively long
period the auxiliary power supply should be
maintained to monitor the insulating gas density.
4.4 Operation of the isolating device for voltage
transformers and voltage sensors
Isolate the relevant switchgear section
before connecting or disconnecting
voltage transformers or voltage sensors.
•
Comply with the safety regulations to EN 50110.
•
Check the switchgear section for the off-circuit
condition as described in section 5.1.
•
Earth the switchgear section and secure the
working area in accordance with section 4 and
EN 50110 standard.
•
Switch the mcbs
1)
of the relevant operating
mechanisms off in order to prevent the
switchgear section being energized by remote
control.
The operating mechanism for the voltage
—
Fig. 4.3.1 Signal lamp
for gas density
manometer
—
Fig. 4.4.1 Location of
the controls for the
voltage transformer
isolating device
(example
configurations)
—
Fig. 4.4.2 Controls
and displays for the
voltage transformer
isolating device
1
Locking plate
2
Actuating plate
3
Padlock (optional)
4
Latching slot
5
Switch position indicator, “voltage
transformer or voltage sensor earthed”
6
Opening for switch position indicator,
“voltage transformer or voltage sensor
connected”
1) mcb: miniature circuit breaker
1
2
3
4
5
6
—
Fig. 4.3.1
—
Fig. 4.4.1
—
Fig. 4.4.2
transformer isolating device is located in the cable
termination compartment on the righthand side
wall (Fig.4.4.1).
Dismantle the cover on the cable termination
compartment. This is done by removing the two
screws above the cover and pulling the cover
upwards.
The controls and indicators for the voltage
transformer isolating device are shown in Fig.4.4.2.
Check the switch position indicator (5 and 6). The
isolating device can be secured with a padlock (3).
Remove the padlock before operating the device.
