The frame serves as the mounting structure for the magnetic core.
The magnetic core which houses the lower pin bearing is secured
to the frame by a locking nut.
The bearing can be replaced, if
necessary, without having to removethe magnetic core from the
frame.
The electromagnet has two pairs of coils.
The coils of each pair
are mounted diametrically opposite one another.
In addition,
there are two locating pins.
The locating pins are used to accurately
position the lower pin bearing, which is mounted on the ·frame,
with respect to the upper bearing, which is threaded into the
bridge.
The electromagnet is secured to the frame by four mounting
screws.
The bridge is secured to the electromagnet and frame by two
mounting screws.
In addition to holding the upper pin bearing,
the bridge is used for mounting the adjustable stationary contact
housing.
The stationary contact housing is held in position by
a spring type clamp.
The spring adjuster is located on the
underside of the bridge and is attached to the moving contact
arm by a spiral spring.
The spring adjuster is also held in place
by a spring type clamp.
With the contacts closed, the electrical connection is made through
the stattionary contact housing clamp, to the moving contact,
through the spiral spring out to the spring adjuster clamp.
The voltage at which the contact drops out can be varied by
rotating the spring adjuster connected to the spiral spring.
INDICATING CONTACTOR SWITCH UNIT
The indicating contactor switch is a small d-e operated clapper
type device. A magnetic armature, to which leaf-spring mounted
contacts are attached, is attracted to the magnetic core upon
energization of the switch.
When the switch closes, the moving
contacts bridge two stationary contacts, completing the trip
circuit.
Also during this operation two fingers on the armature
deflect a spring located on the front of the switch, which allows
the operation target to drop.
The target is reset from the
outside of the case by a push rod located at the bottom of the
cover.
The front spring, in addition to holding the target, provides
restraint for the armature and thus controls the pickup value
of the switch.
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