Alstom FKG1X - Page 70

Function description
FK 3-12 spring operating mechanisms
For circuit
brea
kers
06.04.2011
48-020-212EN02
11/15
•
Cam disc
70.10 turns roller
lever 70.11, w
hich follows i
t, in the
CLOSE
direction. The circuit breaker is closed via main shaft 70.12, operating
lever 70.18 and an attached linkage. At the end of the closing move-
ment, after a 60° rotation, specially designed cam disc 70.10 brings
main shaft 70.12 to a safe, low-impact stop against trip latch 70.16 via
a lever arm of roller lever 70.11. At the same time, cam disc 70.10 has
moved away from roller lever 70.11 and the circuit breaker can be trip-
ped.
•
In the course
of the closing
movement, trip
spring 70.20 is
charged via
trip chain 70.19.
•
The return-stop of
pair of
winding lever
71.32 keeps
the fast gearing
stages from tracking the motion during the closing operation.
•
After closing
shaft 70.09
has turned
through approx.
180°, crank
journal
70.29 passes through bottom dead point B. The Kinetic energy still
possessed by crank wheel 70.30 is returned to closing spring 70.25
(recovered) via chain 70.26. By virtue of this principle, the closing
movement is brought to a gentle, impact-free stop.
•
Control, indicating and
interlock functions
at the end
of the cl
osing
movement:
−
Auxiliary switch 70.21, wh
ich is coupled to
main shaft 70.12 has
made the opening release coil circuit and broken the closing circuit.
The circuit breaker can be tripped electrically, and further actuation
of
the closing
coil is
prevented.
−
A lever (not
shown) controlled by
main shaft 70.12
has disabled
closing latch 70.05, thus mechanically preventing any further release
of the closing system.
−
Circuit breaker
position indicator
70.52 has
turned to
the CLOSED
position with main shaft 70.12.
−
Motor limit
switch 70.24 actuated
via motor lim
it switch
actuating
cam 70.22, has made the motor circuit.
−
The closing
coil circuit
has been broken
by one co
ntact of motor
limit
switch 70.24. Any further electrical actuation of the closing coil is
thus prevented
•
Spring position
indicator 70.31
has simultaneously
moved to
«closing
spring discharged».
•
Circuit breaker
and operating
mechanism
are in
operating state
3.
Operating state 3: Transient
Motor Closing
Opening
•
The
circuit
breaker i
s
ready
for
tripping.