Performing The Power-Frequency Voltage Test - Siemens 8DA Installation Instructions Manual

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Evacuating the circuit-
breaker housings with the
vacuum pump
Filling the circuit-breaker
housings with SF -gas
6
Evacuating and filling the
circuit-breaker housings
with the maintenance unit
Preparing the power-fre-
quency voltage test
36
The circuit-breaker housings of one panel form a common gas compartment. Before
filling SF -gas in, the air must be removed from the circuit-breaker housings (evacuation).
6
The pressure indicator and the maintenance valve for the circuit-breaker housings of one
panel are located on the right side of the housing front (see Fig. 23:, Page 35).
!
Undo the locking cap of the maintenance valve for the circuit-breaker housings.
!
Connect the vacuum pump to the valve. Use short tubes with the largest inside
diameter possible.
!
Evacuate the housings down to a pressure of less than 2 kPa. Manometer indication:
-100 kPa. Measure the pressure with the vacuum pump locked.
!
Depending on the inside diameter and length of the vacuum pump tube, let the
pump operate for another 5 to 15 minutes.
!
Remove the pump tube. The maintenance valve closes automatically.
!
Determine the filling pressure required according to the rating plate and the data
given in Section "Technical data" (see "Description" 14.4, Page 22). The pressure
depends on the gas temperature.
!
Connect the SF -gas cylinder to the maintenance valve of the evacuated circuit-
6
breaker housings.
!
Fill SF into the circuit-breaker housings until the necessary pressure is reached.
6
Check the filling pressure on the pressure indicator of the circuit-breaker housings
and on the pressure indicator of the gas filling equipment.
!
Remove the connecting tube of the gas cylinder from the maintenance valve. The
maintenance valve closes automatically.
!
Refit the locking cap of the maintenance valve.
!
Adjust the limit pressures on the pressure indicator for the circuit-breaker housings
with the supplied square socket spanner.
The procedure to be followed corresponds to the work operations described above for
evacuating and filling without maintenance unit. As against working with vacuum pump
and gas cylinder, the maintenance unit offers better environmental protection due to
reduced SF losses.
6
The same gas pressure data apply as for filling with gas cylinder. Observe the
operating instructions of the maintenance unit!
9

Performing the power-frequency voltage test

The transport units are already tested at the factory at rated short-duration power-
frequency withstand voltage. On the customer's request, the insulating capacity of the
switchgear can be tested at site. This is a repeat test at 80% of the values according to
IEC 62271-200.
DANGER!
High voltage! Danger! If the panel feeders are included in the rated short-duration
power-frequency withstand voltage test, the panel connections are live during the test.
!
Keep a minimum distance of 3 m to the panel connections.
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