TM 5-4310-375-14
Legend for fig 4-3:
22.
Conduit elbow
12.
Spring plate
1.
Reset button
23.
Conduit
13.
Coil
2.
Off-On switch
24.
Conduit connector
14.
Heater coil (3)
3.
Legend plate
25.
Nuts (4)
15.
Power unit
4.
Screw (4)
16.
Movable contact (3)
26. Screws (4)
5. Nut (3)
27. Spacing washers (2)
17.
Retainer (3)
6. Lockwasher (3)
28.
Screw (6)
18.
Spring (3)
7.
Screw (3)
29.
Wiring plate
19.
Screw (6)
8.
Mounting panel
20.
Stationary contact (6)
30.
Operating instruction plate
9.
Motor starter assembly
31.
Control box
10.
Cover
21. Contact set
11.
Armature
(10) Remove stationary contact mounting screws (19). Slide stationary contacts (20) out of the groove in the
molding. A hole in the contact plate is provided for removal with a screwdriver.
(11) Only when necessary, remove conduit elbow (22) from control box (31) and withdraw wires from box.
Remove conduit elbow (22), conduit (23), and disconnect conduit connector (24) from pressure switch.
(12) To remove control box (31) from air receiver saddle, remove the four nuts (25) and screws (26), and two
spacing washers (27) securing the box (28). Remove screws (28), wiring plate (29) and operating instruction
plate (30) only when necessary.
b. Repair/Replacement. Replace defective heater coils (14, fig 4-3), any wires that show evidence of insulation
damage, malfunctioning reset button (1) or ON-OFF switch (2). Replace any other damaged or malfunctioning part.
Replace movable and stationary contacts (16, 20) as a set (21). Refer to following paragraph for assembly of these parts.
c . Reassembly/Installation. Reassemble the motor control box and starter assembly in following sequence.
(1) If removed, install operating instruction plate (30, fig 4-3) and wiring plate (29) with screws (28). Attach
control box (31) to air receiver saddle with four screws (26), two spacing washers (27) and four nuts (25).
(2) If removed, install conduit connector (24) on pressure switch, connect conduit (23) and conduit elbow (22)
running control wires through the conduit into control box (31).
CAUTION
The stationary contacts (20) must be installed so they seat on top of
the terminal plates.
(3) Slide stationary contacts (20) into grooves in the molding, seating on top of terminal plates. Secure with
screws (19).
(4) Install retainers (17) as shown in Sketch "C." The retainer must be installed so the springs (18) will seat
over the extruded hole, with the retainer ends extending away from the moveable contact (16). Install
springs (18) as shown in Sketch "D." Install moveable contacts (16) as shown in Sketch "B." Insert contact
(16), raise end slightly and push into seat.
(5) If power unit (15) was removed as an assembly, push in power unit (15) and tighten the slotted hex head
screws (B). If disassembled, install coil (13) with coil terminal blades engaging the coil terminal clips. Install
and seat the spring plate (12). Slide the armature (11) into its seated operating position. Install cover (10)
and tighten the two screws (A).
4-12
