8
2-1-3 Latched Contactor
Fig. 8 Open condition Fig. 9 Closed condition
Latched contactor has two coils, one is for closing and the other is for releasing. The structure of the latched con-
tactor is shown in Fig. 8 and Fig. 9. When the closing coil is excited, the moving core is attracted to the fixed core
so that it moves in the arrow A direction, and the m oving contact linked to the moving core comes into contact
with the fixed contact, then closes the circuit. At the same time, the rod linked to the moving core moves in the same
direct ion as the moving core and the concave of the rod moves to point （a), t hen the moving core of the release
electromagnet moves in the arrow B direction so as to engage with the concave part. In this state, the moving core
of the closing electromagnet is mechanically held so that even when resetting the excitation of the closing coil, the
contactor is still in closed condition.
When the releasing coil is excited, the moving core of release electromagnet is attracted to the fixed core so that it
moves in the direction of the arrow D shown in Fig. 9, and the moving core disengages from the concave of the rod.
Then, the moving core of closing electromagnet moves in the direction of the arr ow C by the force of the return
spring, and the moving contact linked t o t he moving core separates from the fixed contact, and simultaneously
the circuit opens. The operating circuit is shown in Fig. 10.
Fig. 10 Operating circuit
(Explanation)
ON: Closing by m eans of excitat ion of CC, which ca n be held me-
ch a nica lly. Aft er closin g, con t a ct NO is in "ON " st a te, a n d
contact NC is in "OFF" state.
OFF: Releasing by m eans of excitation of TC. After release, contact
N O r et u r ns t o "O F F " a n d con t a ct N C, t o "ON ". Con t a ct s
NO and NC ar e bu ilt in. The expla nat or y figur e shows a case
where t he power s ources of ON and OFF are t he same. H ow-
ever , even if t h ey a r e different , th e sa m e ON/OFF oper a t ion
is possible.
(Note) ON and OFF contacts should be interlocked.
Remarks: CC: Closing coil
TC: Releasing coil (Tripping coil)
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