Diode and Resistor Assembly

(2) Remove screws (5 and 6), lock washer (7)

(4) Install carrier (14) on armature and secure

and washer (8) and disconnect electrical lead (9) from

with washer (13) spring (12), cup (11) and cotter pin (10).

carrier and yoke.

(5) Install assembled armature on coil and

(3) Remove screws (35) and remove switch (36)

install retainer (38) and screws (37). Install switch (36)

from retainer. Remove screw (37), remove retainer (38)

on retainer and secure with screws (35).

and remove armature from coil.

(6) Connect electrical lead (9) to yoke and

(4) Remove cotter pin (10), cup (11), spring (12)

carrier with screws (5 and 6), lock washer (7) and

and washer (13) and remove carrier (14).

washer (8).

(5) Remove pivot bearing (15) from ar- mature.

(7) Install contacts (4) in carrier and sup- ports

(6) Remove screws (23 and 25), lock washer

and secure with screws (1), lock washers (2) and dished

(26) and washers (24 and 27) and remove support (28)

washers (3).

f. Check Contact Point Gap.

from block.

(7) Remove screw (29) and washer (30) and

(1) Refer to figure 9-13 and check contact point

remove support (31) from block. Remove screw (32) and

gap.

washer (33) and remove block (34) from yoke.

(2) Normally open contacts on contactor should

d. Cleaning, Inspection and Repair.

have an air gap of 0.280 to 0.400 inch (7.11 to 10.1 mm).

(3) Normally closed contacts which open when

the normally open contacts close should have an air gap

WARNING

of 0.130 to 0.250 inch (3.3 to 6.3 mm).

Cleaning compound, solvent (Fed. Spec. P-

(4) Loosen screws and adjust contact point air

D480), used for cleaning, is potentially

gaps to tolerances shown.

dangerous to personnel and property. Do not

(5) Connect a multimeter across contactor coil

use near open flame. Flash point of solvent is

100F to 138F (38C to 59 C).

terminals and apply voltage to check electrical coil.

(6) Contactor should pick up and armature seal

(1) Clean all metal parts in cleaning com-

points at 19.8 volts.

pound, solvent (Fed. Spec. P-D-680) and dry thoroughly.

(7) Contactor must remain picked up at 9.0

(2) Inspect all parts for wear or damage that

volts.

may prevent or impair normal operation. Replace

(8) Contactor must drop out at 2 volts minimum.

unserviceable parts.

(9) If contactor does not operate as noted,

(3) Check for cracked or frayed electrical leads.

disassemble and replace coil and springs.

Repair or replace as necessary.

g. Installation. Refer to paragraph 9-24 and install

(4) Check contactor points for signs of arcing

forward and reverse contactors.

and pitting. Replace worn or pitted contacts.

9-27. Diode and Resistor Assembly

(5) Check springs for cracks, damage and lack

a. General. The diode and resistor assembly (fig. 2-

of tension. Replace unserviceable springs.

7) is mounted in the upper left corner of the contactor

e. Assembly.

panel.

(1) Install block (34, fig. 9-23) on yoke (39) and

b. Removal. Refer to paragraph 9-24 and

secure with screw (32) and washer (33). Install support

remove the diode and resistor assembly from the

(31) on block and secure with screw (29) and washer

contactor panel.

(30).

c. Disassembly.

(2) Install support (28) on block and secure with

(1) Remove diodes (D3 and D4) (1, fig. 9-24)

screws (23 and 25), lock washers (26) and washers (24

from heat sink.

and 27).

(3) Install core (22) in coil (19) and install coil on

yoke. Secure coil and core to yoke with screw (20) and

washer (21). Install spring (18) in core.

9-37