864-5091.9 • INSTALLATION AND OPERATING INSTRUCTIONS • 8DB10 • Revision 06
95/214
Installation
25
Installation work with SF
6
gas after the power-
frequency voltage test
If a rated short-duration power-frequency withstand voltage test has to be carried out at site,
the work with sulphur hexafluoride gas (SF
6
) described in this section must be performed
after the test.
25.1
Installing solid-insulated bars at the panel connection,
and filling the circuit-breaker housings with SF
6
gas
When solid-insulated bars are installed, the circuit-breaker housings are ventilated. The circuit-
breaker housings are already equipped with desiccant bags at the factory in order to eliminate
the residual humidity in the gas filling. In ambient air, the desiccant agent loses its
effectiveness rapidly.
To expose the desiccant bags as briefly as possible to the ambient air, the following work
operations are performed
completely for one bar connection on one panel
.
Mounting
solid-insulated bars
➭ Remove provisional cover from one of the circuit-breaker housings.
➭ Write down the beginning of the ventilation time of the circuit-breaker housing.
➭ Prepare the flange of the solid-insulated bar and the connection flange of the circuit-breaker
housing for assembly.
➭ Mount solid-insulated bar. Tightening torque at the flange: 20 Nm.
➭ If the circuit-breaker housing was ventilated for more than half an hour, replace the
desiccant bags (see page 87, "Installing the panel connections supplied in the accessories,
and filling the circuit-breaker housing with SF
6
gas").
➭ Evacuate the circuit-breaker housings and fill with SF
6
gas
(see page 87, "Installing the panel connections supplied in the accessories, and filling the
circuit-breaker housing with SF
6
gas").
➭ Repeat the above work operations for all other panel connections in the same panel.
DANGER
Danger of suffocation! SF
6
gas is heavier than air and concentrates first near to the floor and in
floor openings.
➭ Do not let SF
6
gas get into the environment.
➭ While working with SF
6
gas, provide for sufficient ventilation.
➭ After working with SF
6
gas, vent the cable basement and any hollows in the floors with
special care.
➭ Observe the safety data sheet for SF
6
gas.
ATTENTION
Desiccant bags that have been fitted in the circuit-breaker housings at the factory are not
effective anymore if the housings remain open for more than half an hour.
➭ Replace desiccant bags in circuit-breaker housings that have been open for more than half
an hour.