User Guide

F-24575-3 Copyright 2008 TAC All Rights Reserved. 6
Optional Mounting
Eliminate the pipehead fitting by using the 22-022 thermostat
conversion kit and the included instructions, plus the
following:
1/4" Plastic Air Lines: Install the 1/4" barbed couplings into
the air lines. Connect the tube assembly to the 3/16" end of
these couplings.
1/4" Copper Air Lines: Solder the barbed couplings into the
copper lines. The tube assembly can then be connected to
the 3/16" end of the couplings.
CALIBRATION
Calibration and Throttling Range Setting
The 2212 series thermostats are factory calibrated and are
shipped with the throttling range set at 3 °F. They should not
require calibration upon installation. However, if it is
necessary, change the calibration or throttling range setting
as follows:
1. Remove the thermostat cover, using a 20-881 thermostat
wrench (1/4” hex wrench), and install a 22-138 branch tap
gauge adaptor into the branch pressure tap hole
(Figure-10).
2. Measure the ambient temperature with an accurate
thermometer. This temperature
must be within the range
of the thermostat
.
3. Move the setpoint adjustment to the measured ambient
temperature, using the internal setpoint indicator.
4. Taking care not to breathe on, or place the hand near the
bimetal, use a 20-881 thermostat wrench (1/16” hex
wrench) to turn the calibration screw until the branch line
pressure indicates 9 psig. Clockwise rotation increases
the branch line pressure. Counterclockwise rotation
lowers the branch line pressure.
5. Reinstall the thermostat cover and set the thermostat to
the desired setpoint.
Internal Stop Kit (Accessory)
The internal stop kit, model 20-712, consists of two screws
and two nuts (Figure-10). Install this kit as follows:
1. Move the setpoint adjustment to one extreme limit.
2. Place a nut in the depression in the top plate and move
the adjustment cam over the nut, to where the slot in the
cam exposes the threads of the nut.
3. Thread a stop screw into the nut far enough to allow the
stop to slide in the slot. Repeat on the other side.
4. Move the setpoint adjustment to the desired
temperature, using the internal setpoint indicator.
5. Slide the stops to the desired limits and tighten both
screws.
MAINTENANCE
The thermostat requires no maintenance.
Regular maintenance of the total system is recommended to
assure sustained, optimum performance.
FIELD REPAIR
None. Replace an inoperative thermostat with a functional
unit.
DIMENSIONAL DATA
˚F ˚C
5
2
12
6
2
T R
H
Internal Setpoint
Indicator
Branch
Pressure
Tap
Setpoint Adjustment
Thermostatic
Bimetal
Calibration
Screw
Cover Scale
Setpont Indicator
Celsius
Scale
Fahrenheit
Scale
Limit Stops (2)
(Accessory)
Figure-10 Thermostat Calibration Features
and Limit Stop Accessory.
1-1/4
(3.18)
1-3/8
(3.5)
1/8
(.318)
1-3/8
(3.5)
2-1/32
(5.16)
2-1/32
(5.16)
MB
Dimensions are in inches (mm).
Figure-11 Mounting Dimensions.