Description and operation
Description of the interrupting chambers
L12--105EN/03
2/4
01--2011
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GRID
Interrupting chamber
Quenching medium
The quenching medium is pressurized SF
6
gas or -- in particular instances --
pressurized SF
6
+CF
4
gas mixture.
Interrupting principle
The interrupting chamber is of thermal blasting type, using the energy from
the arc, with an auxiliary autopneumatic effect.
Diagram
4
2
1
Description
The interrupting chamber has been designed in such a way as to increase the
mechanical resistance of the working part and take advantage of the low wear
rate of the contacts subjected to the arc in SF
6
. The working part is enclosed
in a leak tight ceramic envelope, providing insulation between the
circuit--breaker input and output.
The chamber is made up of the following elements :
Mark
Component
Information
(1)
Envelope
Can have a long creepage
distance,
depending
on
the
pollution level.
(2)
Fixed contact
(4)
Moving contact
It is worked by the operating
mechanism and contains the
blasting device.
