2-51. CONTROL BOX ASSEMBLY.
a. General. The control box assembly houses the switches, indicator lamps, and warning lamps needed to run
the ROWPU. It is located on the upper left of the control panel. This paragraph describes removal of the control
box assembly from the control panel, disassembly, repair, inspection, cleaning, reassembly, and installation.
b. Removal. (Figure 2-54)
ELECTRICAL HIGH VOLTAGE
Electricity can cause serious injury or death. Be certain that all
power is removed before performing maintenance on electrical
(1) Disconnect power cable (1) from control box assembly (6).
(2) Disconnect backwash timer control connector (2) from control box assembly connector (18).
(3) Disconnect panel light cable (19) from panel light in accordance with paragraph 2-66.
(4) Remove four nuts (3) and four lockwashers (4) from four bolts (5) that secure control panel.
(5) Remove control box assembly (6) from control panel.
c. Disassembly. (Figure 254)
(1) Remove fourteen screws (7), fourteen lockwashers (8), and fourteen flat washers (9) from control box
assembly and cover (10).
(2) Remove cover (10) and gasket (11) from control box assembly. Discard gasket (11).
Identify and tag each cable and wire before disconnecting.
Remove tags after wires are reconnected and checked.
(3) Disconnect and remove terminal blocks in accordance with paragraph 2-62.
(4) Disconnect and remove all toggle switches in accordance with paragraph 2-58.
(5) Disconnect and remove all indicator lamps and lamp holders in accordance with paragraph 2-59.
(6) Disconnect and remove EMERGENCY STOP switch in accordance with paragraph 2-58.
(7) Remove nut (12), lockwasher (13), and electrical flat washer (14) from grounding screw (17).
(8) Remove wire lugs (15) and toothed lockwasher (16) from grounding screw (17).
(9) Remove grounding screw (17) from control box assembly (6).
(10) Remove power cable receptacle from control box assembly (6) in accordance with paragraph 2-60.
(11 ) Remove all cable clamps and wiring harnesses from control box assembly (6) in accordance with
(12) Remove backwash timer cable (18) and panel light cable (19) from control box assembly (6) in
accordance with paragraphs 256 and 266.
(1) Wash control box assembly with soap and water solution using a stiff brush. Prepare for repainting, if
(2) Remove dirt and rust from threads of screws and nuts.