c. Visually inspect the heating element and contact
e. Push in the cap on the fuseholder (11) and rotate
points in the time delay unit. Replace the complete unit
the cap counterclockwise to remove it from the
if the points are burned or pitted, or if the heating ele-
fuseholder. Remove the fuse (12) from the fuseholder.
ment is damaged. Use an ohmmeter to test continuity.
Tag and unsolder the two red wires from the
There must be continuity between the blue lead and
fuseholder. Remove the fuseholder nut and pull the
the white-black lead, and between the two red leads.
fuseholder from the front of the control panel. Remove
the spare fuseholder the same way.
yellow leads, or any other pair of leads, or between any
f. If the terminal block strip (16) must be replaced,
lead and the time delay assembly housing. Replace the
unsolder the remaining leads. Remove the screw (13),
time delay assembly if these requirements are not met.
nut (14), and lock washer (15) securing the terminal
block strip to the control panel, and remove the ter-
If the time delay assembly has not been removed from
minal block strip.
the control panel, the yellow, blue, and green leads
must be disconnected from the terminal block before
nuts (17), lock washers (18), and screws (19), and remove
the continuity test is performed.
the receptacles and gaskets (22) from the control panel
d. Replace the boot (4, fig. 6-1) if it will not form a
(25). Unscrew the retainer from the rear of the recepta-
tight seal around the RESET switch. Replace gaskets
cle and pull out the plug to provide access to the lead-
to-pin connections. Unsolder the pins from the leads
e. Inspect all wiring for frayed or broken insulation.
and remove the receptacles.
Replace damaged leads. Replace the terminal block if
h. When control panel components have been
its insulation is cracked or broken.
removed, you can separate the panel plate (24) from the
6-4. Reassembly and Installation.
control panel (25) for cleaning and replacement.
a. Install the components on the control panel in the
6-3. Cleaning and Inspection.
b. When installing the THERMO and POWER recep-
Clean parts in a well-ventilated area.
tacles (20 and 21) on the control panel, slide the plug
Avoid inhalation of solvent fumes and
and retainer over the ends of the leads before soldering
prolonged exposure of skin to cleaning
the leads to the pins in the other segment of the recep-
solvent. Wash exposed skin
tacle. Make sure the wire color will be correct when the
thoroughly. Dry cleaning solvent (fed.
key in the plug is inserted in the keyway on the recep-
spec. P-D-680) used to clean parts is
tacle housing. Slide the plug into the housing to cover
potentially dangerous to personnel
the soldered connections and secure by installing the
and property. Do not use near open
flame or excessive heat. Flash point of
c. Use the wiring diagram (fig. 1-4 as a guide when
solvent is 100°F (38°C).
installing the leads on the components.
d. Install the control panel in the front of the heater
a. Clean parts with a dry soft-bristle brush. Remove
case and secure with five screws (1, fig. 6-1) and lock
greasy or gummy deposits with a cloth dampened
lightly in dry cleaning solvent (fed. spec. P-D-680).
e. Reinstall the top and side cover panels, connect the
b. Inspect leads and components for worn or broken
power and thermostat plugs, and test heater for proper
insulation, signs of overheating, or other defects.
Replace defective parts.