14 SafeRing/SafePlus 36kV
| Installation and operating instruction
Topping up of SF
6
gas in SafeRing/SafePlus
Potensial risk!
Operators must be trained and qualified for SF
6
gas
handling
Following equipment is needed: SF
6
gas bottle with mano-
meter and reduction valve, bottle for recovery of SF
6
/air mix-
ture, adapter and pressure measuring device. It is important
that the pressure measuring device shows absolute pressure.
If you have a pressure measuring device showing over-
pressure, please contact ABB for instructions (NHP 408025).
1. Remove the front cover and unscrew the pressure indicator
by unscrewing the hexagon nut as shown on the figure at
the right.
2. Screw the adapter to the valve. The tightening torque is
max 45 Nm.
3. Before connecting the hose from the gas bottle to the
adapter, the air in the hose must be removed by running
SF
6
gas through the hose. The SF
6
gas must be recovered.
4. When gas is flowing into the RMU/switchgear, the mano-
meter on the gas bottle has to be observed. When it shows
0,4 bar at ambient temperature 20° Celsius, (1,4 bar ab-
solute) the gas filling must be stopped. See table for filling
pressure below.
SF
6
-gas temp
Absolute filling
pressure
o
C
mbar
0
1305
5
1328
10
1352
15
1376
20
1400
25
1424
30
1448
35
1472
40
1496
4.4 GAS PRESSURE
SafeRing / SafePlus contain SF
6
gas with a nominal pressure
of 1,4 bar at 20
o
C.
SafeRing / SafePlus are «sealed for life» and is fitted with a
temperature-compensated pressure indicator.
Pointer in green area - unit has correct pressure.
Pointer in red area - pressure is too low.
A temperature-compensated device emitting an electrical sig-
nal to indicate low gas pressure can be supplied on request
5. Remove the filling hose and connect the pressure device to
check the pressure inside the RMU/switchgear.
6. When the correct pressure of 0,4 bar (1,4 bar absolute)
is obtained, remove the adapter, check that the sealing
between the pressure indicator and the valve is smooth
and clean, and screw the pressure indicator to the RMU/
switchgear with tightening torque max 45 Nm as shown
above.
Green area
Red area
Note! Screw/unscrew on this hexagonal
nut only. The pressure indicator can be
dismounted from the switchgear with-
out SF
6
leakage from the SF
6
tank
Spring-loaded
valve
Filing pr
essur
e Bar abs
Altitude
Air
SF
6
4000
30
o
20
o
10
o
1
1,05
1,1
1,15
1,2
1,45
3500
500
1000
1500
2000
2500
3000
0
1,4
1,25
1,3
1,35
