T822/TS822 Spec Sheet

T822, TS822 HEATING/COOLING THERMOSTATS
7 68-0095-2
Recalibration
These thermostats are calibrated at the factory and should not
require recalibration. If the thermostat seems out of
adjustment, first check for accurate levelling. To check
calibration:
1. Move the temperature setting lever to the low end of the
temperature scale.
2. Remove the thermostat cover. Move the temperature
setting lever until the switch just makes contact. (The
mercury in the switch will drop to the contact end of the
tube.)
3. Replace the thermostat cover and wait five minutes for
the cover and the thermostat to lose the heat it has
gained from your hands. (If the thermometer pointer and
the temperature lever indicator read approximately the
same, no recalibration is needed.)
4. If recalibration appears necessary, use this procedure:
a. Place the temperature setting lever at the same set-
ting as the thermometer.
b. Remove the thermostat cover.
c. Insert 104994A Calibration Wrench (ordered sepa-
rately) onto the hex nut under the coil. See Fig. 10.
Holding the setting lever so it does not move, turn
the wrench clockwise until the switch just breaks
contact.
d. Remove the wrench and replace the thermostat
cover.
e. Move the temperature setting lever to a low setting.
Wait at least five minutes for the temperature to sta-
bilize.
f. Slowly move the temperature setting lever until it
reads the same as the thermometer.
g. Remove the cover. Holding the temperature setting
lever so it does not move, reinsert the wrench and
carefully turn the wrench counterclockwise until the
mercury just rolls to the left end of the tube, but no
farther.
h. Recheck the calibration by setting the thermostat
System switch for the desired operation.
i. Replace the cover.
Fig. 9. Recalibrating thermostat.
CALIBRATION
WRENCH
COIL SHOWN WITHOU
T
HEAT ANTICIPATOR
M2044A