72
W
1 Filling
flange
1 Gas
cylinder
2
Pressure reducer regulating valve
3
Precision pressure gauge (-1.0 bar up to 9.0 bar)
4 Safety
valve
Fig. 55
Gas filling device connected
At an ambient temperature other than +20°C, the SF
6
filling pressure must be taken from the diagram (Fig. 1).
The filling pressure may be up to 0.30 bar over the nominal pressure curve (temperature-independent).
When filling is completed, unscrew the hose of the filling device and close the filling flange. Screw on the union
nut by hand (4 Nm). Ensure that all parts are clean.
4.7.3 Leakage Test after Installation
After successful assembly of the circuit-breaker and filling with SF
6
gas, the tube connections should be checked
for leakages.
A leak detector must be used. If a leak is detected:
WARNING
Release the SF
6
-pressure before working on the screw connections of the gas chamber.
If a leak is discovered, undo the leaking connection and check the sealing surface for damage or foreign bodies.
Then fit a new seal, remake the connection and repeat the leak test.
