AT&T Bell System 1A Maintenance Manual page 2

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SECTION C71.553.01
2.05
Cords and Plugs shall be replaced if found
badly fraye~ or defective.
2.06
If operating units or key units become de-
fective, replace entire code sending station
with KS-14468 type.
KS-14468
2.07
Lubrication: On the list 1 units there are
two bearings at the end of the camshaft
opposite the motor, one supporting the main cam-
shaft and the other the cam which controls the
motor circuit. List 2 units have, in addition, a bear-
ing at each end of the upper camshaft. All bear-
ings are equipped with oil-saturated felt washers.
When lubrication becomes necessary, these bear-
ings should be lubricated with KS-7470 oil applied
to the felt washers or by touching the washers
with a piece of bare wire which has been dipped
into the oil. The bearings of the list 1 units may be
reached by removing the back of the set. However,
it will be necessary to remove the list 2 unit from
the case for lubrication by removing the screws
from the bottom of the case. The two bearings for
the upper camshaft then may be reached from
the top of the unit. The bearing for the lower cam-
shaft and for the motor control cam may be
reached from the bottom of the unit. Oil should be
applied sparingly to the teeth of the gears con-
necting the upper and lower camshafts.
Note:
The motor is a sealed unit and needs no
lubrication.
2.08
Speed: The code sending station should
complete one cycle (3 complete codes) for
signal 26 in approximately 30 seconds. Replace
the code sender, if necessary, as there is no adjust-
ment for speed of the synchronous motor.
2.09
Busy Lamp: Note that the busy lamp
flashes the selected code as the signals
sound. Replacement lamp is NE45 1/4-watt 110-
to 125-volt, candelabra base.
3.00 RELAY SETS
3.01
Th€ KS-8230, Lists 1 and 2 relay sets have
carbon contacts to take the arcing that
occurs due to signal lines being equipped with a
large number of signals. These carbon contacts,
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when badly worn, may be replaced with new car-
bon contacts.
3.02
The relays and other parts of transformer
relay sets used on 1B code calling systems
do not normally require any adjustments. If any
of these units become defective, replace with a
new or repaired unit.
3.03
The relays in the KS-7340 and KS-7357 re-
lay sets and the KS-8233, List 2 trans-
former relay set have a 2-position armature air-
gap. The close airgap should be used for manual
ringing telephone lines, and the wide airgap
should be used for machine ringing telephone
lines, especially in dial areas.
4.00 SIGNALS
4.01
Bells and Chime Signals require no adjust-
ment or lubrication except the chime sig-
nals which have an adjusting screw at the bottom
of the plunger guide for adjusting the volume of
the signal. The volume should be adjusted to meet
the customer's requirements. If plunger should
stick in its guide, remove guide and plunger if
practicable and clean with carbon tetrachloride.
If it is impracticable to remove these parts or
cleaning does not correct difficulty in those cases
where the plunger and guide can be removed, re-
place the entire signal.
4.02
Horns: Foreign substances may collect be-
tween the diaphragm and the front plate.
In these cases remove front plate and brush out
the dirt (horn plate position should be noted at
the time of removal, so it may be replaced in its
identical position). The volume of sound emitted
by horns may be adjusted by means of a screw and
locknut which are provided for this purpose. As in
the case of bells, the volume should meet the cus-
tomer's requirements. Defective horns should be
replaced.
4.03
Signals having relays which operate on
telephone ringing voltage have a 2-position
armature airgap. The close airgap should be used
for manual ringing telephone lines, and the wide
airgap should be used for machine ringing tele-
phone lines, especially in dial areas.
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