TM 5-4520-256-14
3-32.
RETURN TEMPERATURE THERMOSTAT MAINTENANCE - Continued.
b. Inspection.
(1) Inspect wiring for cracked, burned, or deteriorated insulation, and exposed conductor.
(2) Inspect thermostat body for cracks, damage, and corrosion.
c. Cleaning.
WARNING
Cleaning solvent, Federal specification P-D-680, is toxic and flammable. Use only in a well-
ventilated area. Avoid prolonged breathing of fumes. Keep solvent away from flames. Do not
use in excessive amounts. Avoid skin contact.
(1) Clean thermostat with cleaning solvent (item 11, Appendix E).
(2) Allow to dry.
d. Testing.
(1) Connect a multimeter across the thermostat leads (2).
(2) The resistance of the thermostat is dependent on the temperature and should be within 20 percent of the
value listed below.
TEMPERATURE
RESISTANCE
0°F (-18°C)
1,000,000
20°F (-7 C)
50,000
40°F (4°C)
25,000
70°F (21°C)
12,000
90°F (32°C)
7,000
e. Installation.
(1) Connect thermostat leads (2) to terminals 3 and 4 of temperature controller.
(2) Install thermostat (1) into clamp (3).
(3) Install two screws (6), two lockwashers (5), two flat washers (4), andtwo clamps (3) onto wall (7).
(4) Install air filters and access door per para 3-10d.
3-100 Change 3
