contacts are clamped to a contact shaft rotated by the
(2) Remove
three
locknut
and
connector
movement of the coil arm. As contact is made, an auxiliary
assemblies (1) and remove wire cables.
contact is also closed by a roller on the coil arm. This auxiliary
(3)
Remove four screws (2) to release magnetic
contact provides power to the coil after the starting button is
contactor.
released, and thus holds the main contacts in a closed position.
6-35. Magnetic Contactor Cleaning, In spection and Test
Clean all parts thoroughly, using a small brush, if necessary, to
clean threaded areas. Burnish contact point with fine file, being
careful to blow away all metallic particles removed. Inspect
contact points for pitting. Remove pits with a fine abrasive cloth
If deeply pitted, replace. Inspect insulator for cracks. If cracked
or broken, replace the insulator Inspect nuts and studs on
terminal plate for stripped or damaged threads. Replace
defective parse. Remove any carbon deposits from insulator
with a small brush and cleaning solvent Using an ohmmeter,
check magnetic contactor coil for continuity.
Replace if
defective.
6-36. Magnetic Contactor Installation
a. Installation.
(1) Position magnetic contactor assembly on
camera rear support plate and secure with four screws (2, fig.
(2) Insert three cable assemblies and secure each
in place with a locknut and connector assembly (1)
(3) Connect all leads to terminal block (4) and coil
(6-. Remove tags from leads. Replace cover.
6-37. Electronic Sensing Devices
is an instrument used to produce a stabilized arc light from the
carbon electrodes (20, fig. 4-6), providing a constant intensity of
light over the copy. The device (6, fig. 6-1) electronically
maintains the gap between the carbon ends at a set distance
which remains constant during operation, thereby eliminating
any variances in light intensity. The electronic sensing devices
are mounted ver-tically on the inner side of the rear truss
support (9) located on the copyboard end of the camera. The
wiring cable (1) housing the arc lamp circuit wires, is connected
to the device (6) by a cable connector socket (8). The sensing
device cannot be checked externally or repaired, it must be
replaced. Since there are separate sensing devices for each
lamp, a trouble effecting both lamps cannot be caused by the
sensing devices (except in the unlikely event both should fail
simultaneously. If one lamp flickers or does not operate, while
the other does, switch the lamp cables to the sensing devices.
If the lamp which had operated normally then fails, replace the
sensing device
b. Removal.
Figure 6-18. Magnetic contactor, installed.
(1) Release the connector nut (7, fig. 6-1 (from the
sensing device (6 I, and pull the cable connector socket (8) from
6-34. Magnetic Contactor Disassembly
its mating plug on the device.
a. Removal.
(2) Remove the four mounting screws (5), two on
(1) Remove cover and disconnect all leads from
each side of the device. Release the device from rear truss
terminal block (4, fig. 6-18) and coil (6). Tag all wire leads.
support (9).
6-16
