Siemens GMSG Instruction Manual page 27

Construction and mode of operation of
secondary release and undervoltage
release
Refer to Figure 19: Construction of
secondary shunt release and Figure 20:
Latch details on page 26 and Figure 21:
Undervoltage lock/operate selection.
The release consists of a spring power-
storing mechanism, a latching device and
an electromagnet. These elements are
accommodated side-by-side in a housing
(3.0), with a detachable cover and three
through-holes (5.0) for fastening screws.
The supply leads for the trip coil are
connected to a terminal block (33.0).
The energy-storing mechanism consists of
the striker pin (23.0) and its operating
spring (31.0), which is mostly located
inside the striker pin (23.0). When the
spring is compressed, the striker pin is held
by a latch (25.0), whose sloping face is
forced against the appropriately shaped
striker pin (23.0) by spring (27.0). The
other end of the latch (25.0) is supported
by a partly-milled locking pin (21.0) (refer
to Figure 20: Latch details on page 26) that
pivots in the cover sheets of the magnet
armature (9.0). The armature (9.0) pivots
in front of the poles of the U-shaped
magnet core, (1.0) and is pulled away from
it by the tension spring (11.0).
If the magnet coil (7.0) of the shunt
release 3AX1101 is energized by a trip
signal, or if the tripping pin (15.0) is
mechanically actuated, magnet armature
(9.0) is swung against the pole faces.
When this happens, the latch (25.0) loses
its support and releases the striker pin
(23.0), that is forced out by the spring
(31.0).
On the undervoltage release 3AX1103, the
latch (25.0) is held by the locking pin
(21.0) as long as the armature (9.0) is
attracted (energized) (refer to Figure 17:
Operator sequence operation diagram on
page 24). If the circuit of the magnet coil
(7.0) is interrupted, the armature (9.0)
drops off, thus causing the latch (25) to
lose its support and release the striker pin
(23).
Vacuum interrupter/operator
Position A: locked
23.0
29.0
Position B: unlocked (operating position)
23.0
29.0
Cancel the lock for the undervoltage release by shifting the locking screw (29) from
A to B.
23.0 - Striker pin
29.0 - Screw
120 or 240 Vac
supply
A
B
A
B
Figure 21: Undervoltage lock/operate selection
01
T
SD5
24
52o
23
A1
(+)
52T
1
(-)
A2
34
2
52o
(+)
33
(-)
Capacitor trip
Figure 22: Capacitor-trip device
Capacitor
Resistor
Rectifier
27