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CONTACT MOLDIN
G
ASSEMBLY
NjO CONTACT WIRE
COMMON CONTACT
PIVOT
SPRING
ARMATURE
ARMATURE
ARMATURE
RETURN SPRING
ARMATURE ACTUATOR
Figure 6-5. PM Relays
Contact Replacement
When
a
machine malfunction is
caused
by PM
relay
contacts failing to make,
it
may
not
be necessary to
replace the entire relay.
The following procedure
should be used to replace individual contact wires and
check common contacts for dust or corroded areas.
1. Remove the two relay yoke mounting screws
and separate the contact moulding assembly from the
yoke assembly.
This will expose the contact wires
and common contacts. Use care topreventbreakage
of coil wires from relay moulding.
2. Using a screwdriver, press the contacts free
of the locating hole and remove them from the
moulding.
3. Inspect the common contact point for dust or
corrosion film.
If
necessary, lightly burnish the
point. Do not attempt to clean the common contact
if
it
is
pitted or burned. This will result in increased
air gap and loss of contact tension.
4. Check new contacts for correct configuration
before installing (Figure 6-7).
5. Install new contact
wires
one ata
time
to avoid
twisting.
N/
or-
8~
N/
O
~~
Vi
I
e
~~
0
~~
N/
e
~ ~
~<
19
I
N/e
Amootur. Normal
Atmatur.
AlIrOCled
Figure 6-6. PM Schematic
6-4
6.
Re-assemble yoke
to contact moulding assem-
bly.
The armature must be centered on the contact
wires with
equal dimensions between the end contacts
and
the
ears
of the moulded armature actuator. Be
certain that the yoke is held tight against the mounting
pads
.
7.
Check all wires to see that none are crossed
or misplaced from the locating hole. Checkfor free-
dom of armature and coil leads and proper seating
of
the
armature
pivot springs. Check the
operation
of
the relay contacts with the dynamic timer
or
oscillo-
scope.
CIRCUIT BREAKERS
The read feed has CB's that are continuously running
and some that are under control of the read clutch.
Both sets of circuit breakers turn at 800 rpm. The
punch feed has three sets of CB's, one set is under
control of the punch clutch while the other two sets
are continuously running.
One set of continuously
running CB's turn at 250 rpm while the other set
turns at
1333
1/3 rpm. Identification of these circuit
breakers
is
as follows:
~
C ; ;
;STRAI
G
HT
1
J
f.o-
!.
- -
--
STRA IGHT
- - - - - - "
Figure 6-7. PM Relay Contact Wires
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