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SECTION IB-1G-500
INSTALLATION & OPERATION INSTRUCTIONS
PAD-MOUNTED SWITCHGEAR TYPE PSI
REV. 1.6 - NOVEMBER 2017
PAGE 6
Interrupter Operation
The Auto-jet
switch has a highly efficient system for load cur-
®
rent interruption. This device consists of a piston (A) mounted
in the cavity of the upper insulator. The movable arcing probe
(B) engages a tulip contact (C) inside the piston. As the switch
blade (D) is pulled open by the stored energy mechanism, the
main contacts open. The piston is pulled forward by means of
the movable arcing probe, which compresses a heavy gauge
spring encircling the piston and a spring encircling the arcing
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probe. At the end of its travel, the piston released from the arc-
ing probe and, under the action of the heavy spring, is rapidly
pushed backward into the cavity. This travel produces a jet of
laminated compressed air up through the hollow center of the
piston, which extinguishes the arc. The spring encircling the
movable arcing probe rapidly retracts the probe and increases
the speed of separation, which prevents restrike.
Switch closed with opening
spring relaxed.
Switch closed with opening
spring charged by manual
operating handle.
Main contacts parted, puffer
and arcing springs charged.
(Simulated condition for
illustrative purposes,
actual duration of event is
approximately 1/2 cycle.)
Switch open with latch
engaged to hold switch in
position.
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