t.a.c. 2212-318 Instruction manual

Printed in U.S.A. 8/08 ©Copyright 2008 TAC All Rights Reserved. F-24576-4
Application
The 2212-318 and 2212-319 Dual Setpoint/Deadband
Pneumatic Room Thermostats are designed for the
proportional control of pneumatic valves, damper
actuators, or other final control devices in
environmental control systems. These devices are
used when it is desirable to set up, between selected
heating and cooling setpoints, a temperature span
within which the HVAC system uses no energy for
heating or cooling. The high capacity, two-pipe,
pilot-operated, relay-type design provides pneumatic
feedback for accuracy and stability over the entire
operating range.
These thermostats are available in either direct- or
reverse-acting models, each utilizing two bimetals, one
heating and one cooling, to interrupt the deadband
(branch) pressure. In the direct-acting model, the
heating bimetal modulates the pressure between zero
and the deadband pressure, and the cooling bimetal
modulates the branch pressure between the deadband
pressure and main air pressure. In the reverse-acting
model, this action is reversed. The deadband pressure
is adjustable in the field, to adapt to specific
applications. Two concealed setpoint dials, one
heating and one cooling, are used to set the individual
heating and cooling setpoints to the desired values.
This creates the desired deadband between the two
selected setpoints. All calibration functions are
accessible from the front of the thermostat. The use of
a blank cover (21-928) is recommended with this
device. Other cover options may be utilized if desired.
Features
•Factory-calibrated, stainless steel ball-in-seat
provides pneumatic feedback for stable, linear
operation.
•Deadband is easily selected by setting the desired
heating and cooling setpoints.
•Field-adjustable deadband output pressure is
factory set at 8 psig.
•Leak-proof, self-closing branch gauge tap.
SPECIFICATIONS
Action: Proportional.
Setpoint Range:
Heating, 57 to 75 °F (14 to 24 °C).
Cooling, 65 to 83 °F (18 to 28 °C).
Throttling Range: 1.5 °F (approx.) non-adjustable for each
setpoint.
Maximum Air Pressure: 30 psig.
Main Air Consumption: 30 scim.
Setpoint Adjustment: Individualconcealedadjustmentsfor
heating and cooling by means of a 20-881 calibration wrench.
Calibration:
Deadband, Factory-set at 8 psig (adjustable).
Direct-Acting Models,
Heating 5.5 psig at setpoint.
Cooling 10.5 psig at setpoint.
Reverse-Acting Models,
Cooling 5.5 psig at setpoint.
Heating 10.5 psig at setpoint.
Construction:
Mechanical Components, Die cast aluminum, stainless
steel, and glass-filled nylon.
Diaphragm, Fabric-reinforced Neoprene.
Air Lines, Connect to thermostat nipples with
spring-reinforced plastic tubes.
Branch Connections, Equipped with internal fiters.
Environment
Humidity: 5 to 95% relative humidity, non-condensing.
Locations: NEMA Type 1.
2212-318
2212-319
Dual Setpoint/Deadband
Pneumatic Room Thermostats
General Instructions
Blank Cover Shown
(Covers must be ordered
separately except as noted.)

2©Copyright 2008 TAC All Rights Reserved. F-24576-4
ORDERING DATA
Table-1 Model Chart — Thermostats.
Wholesale
Number Replaces Model Action Description
2212-318 T35-301 Direct Includes (2) 1/4" x 3/16"
barbed couplings, 6" piece of
polyethylene tubing, 20-714
wall plate, 20-711 mounting
plate, and mounting screws.a
aOther rough-in hardware and installation fittings must be ordered
separately.
2212-319 T36-301 Reverse
Table-2 Model Chart — Thermostat Replacement Kits.
Wholesale
Number Replaces Model Action Description
2212-538 T35-301 Direct Includes thermostat, 21-928
blank cover, and 22-022
conversion kit
2212-539 T36-301 Reverse
Table-3 Covers.
Wholesale
Numbera
aThermostat covers with concealed setpoint adjustment inlude setpoint adjustment cover 21-800 (black) or 21-801 (Euro-white).
Replaces
Model Color Material Dial
Markings Setpoint Adjustment Thermometer
21-928 C2-42 Satin Chrome Metal Blank Concealed No
22-1028 C2-48 Euro-white Plastic
21-957 C11-42 Satin Chrome Metal None Concealed Yes
(External)
22-1057 C11-48 Euro-white Plastic
21-960 C14-42 Satin Chrome Metal Blank Concealed Yes
(Internal)
22-1060 C14-48 Euro-white Plastic
Table-4 Accessories.
Wholesale
Number Replaces Model Description
20-695 10-15 Aspirating box
20-707 10-53 Metal thermostat guard
20-710 10-57 Universal mounting fitting
20-712 10-59 Dial stop kit
20-714 10-77 Black wall plate
20-715 10-62 Clear thermostat guard
20-716 10-78 Insulated back plate
20-850 — Thermostat mounting plate
20-881 N2-4 Calibration wrench
21-473 10-73 Drywall mounting bracket
21-800 10-72 Setpoint adjustment cover (black)
21-801 10-81-48 Setpoint adjustment cover (Euro-white)
21-876 10-76 Opaque thermostat guard
22-022 — Thermostat conversion kit
22-023 — Thermostat conversion kit
22-138 MCS-GA Branch tap gauge adaptor
900-002 — Thermostat calibration kit
TYPICAL APPLICATIONS
(Piping Diagram)
INSTALLATION
Inspection
Inspect the package for damage. If damaged, notify the
appropriate carrier immediately. If undamaged, open the
package and inspect the device for obvious damage. Return
damaged products.
BM
HC
2212 Series
Dead-Band Thermostat
HWS CWS
N.O. Heating Valve
3 to 8 psig N.C. Cooling Valve 8 to 13 psig
M
Figure-1 Direct-Acting Application.

F-24576-4 ©Copyright 2008 TAC All Rights Reserved. 3
Requirements
•Tools (not provided):
– Appropriate screwdriver for mounting the thermostat
– 20-881 Thermostat calibration and cover screw
wrench (or 1/16” and 1/4” hex wrenches)
•Training: Installer must be a qualified, experienced
technician
•Appropriate accessories
•Piping diagrams
Location
Caution:
•Do notlocate thethermostat near sourcesof heat orcold,
such as lamps, motors, sunlight, or concealed ducts or
pipes. Doing so will affect the accuracy of the thermostat.
•Avoidinstalling the thermostat on outside walls. If such a
location is necessary, mount the thermostat on an
insulated back plate (accessory item).
•Mount thermostats only after the wall surfaces have
been finished.
Locate the thermostat where it will be exposed to an
unrestricted circulation of air, which represents the average
temperature of the controlled space.
Mounting
Standard Mounting Options
Mount the thermostat according to the applicable figure
(Figure-2 through Figure-8). See Figure-12 for mounting
dimensions.
BranchMain
Polyethylene
Tubing Air Supply
20-714
Wall Plate
(included with
thermostat)
21-473
Drywall Mounting
(order separately)
20-693
6 in. Tube Assembly
with Eyelets
(included with
thermostat)
Thermostat
Mounting Screws
(included with thermostat)
Cover
(order separately)
21-611
1/4 x 3/16 in. Barbed Couplings
for Plastic Tubing
(included with thermostat)
Figure-2 Flush Mounting of Thermostat.
(2) #6 Self-Tapping
Screws
20-693
6 in. Tube Assembly with Eyelets
(included with thermostat)
20-850 Plate
Thermostat
Cover
(order separately)
(2) Screws for Electrical
Box Mounting
Pre-plumbed
Electrical Box
Wall
Polyethylene Tubing
Air Supply
Branch Main
Figure-3 Flush Mounting of Thermostat, Using 20-850 Plate
and Pre-Plumbed Electrical Box.
Bracket
Mounting Screws
(included with thermostat)
20-693
6 in. Tube Assembly with Eyelets
(included with thermostat)
Skirt
Wall Plate
Thermostat
Cover
(order separately)
Polyethylene Tubing
Air Supply
Branch Main
Figure-4 Thermostat Mounted with 22-022
Conversion Kit, Using Wall Plate and Skirt, to
Replace Competitive Thermostats.

4©Copyright 2008 TAC All Rights Reserved. F-24576-4
Optional Mounting
Eliminate the pipehead fitting by using the 22-022 thermostat
conversion kit andthe 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
copperlines.The tubeassemblycanthen be connected tothe
3/16" end of the couplings.
Bracket
20-693
6 in. Tube Assembly with Eyelets
(included with thermostat)
Wall Plate
Thermostat
Cover
(order separately)
Mounting Screws
(included with thermostat)
Polyethylene Tubing
Air Supply
Branch Main
Figure-5 Thermostat Mounted with 22-022
Conversion Kit, Using Wall Plate Only, to
Replace Competitive Thermostats.
Wall Plate
Pre-plumbed
Electrical Box
(optional)
Air Supply Tubing
Branch
(2) Thermostat
Mounting Screws
(included with thermostat)
3/16 in. Tygothane
Tubing with Eyelets
(included with thermostat)
Thermostat
Cover
(order separately)
Insert
1 Provided in the 22-023 thermostat conversion kit.
2 Optionally, the thermostat may be mounted with the #6 x 1 in.
self-tapping screws provided in the 22-023 kit.
3 Use the #8 x 1 in. mounting screws provided in the 22-023 kit
when mounting the wall plate directly to the wall, without an
electrical box.
2
1
1
Wall
3/16 in. x 1/4 in.
Barbed Couplings
(included with thermostat)
Main
(2) #6 x 1 in.
Mounting Screws
(for electrical box mounting)
1 3
Figure-6 Thermostat Mounted with 22-023 Thermostat
Conversion Kit.
Block Branch
Main
Polyethylene
Tubing
Air Supply
Remove Locator
and Adaptor
20-710
Mortar Joint Fitting
(order separately)
20-693
6 in. Tube Assembly with Eyelets
(included with thermostat)
Thermostat
Cover
(order separately)
Mounting Screws
(included with thermostat)
20-714
Wall Plate
(included with
thermostat)
Figure-7 Thermostat Installation Using
Pipehead in Masonry Wall.
Branch Main
Polyethylene
Tubing
Air Supply
Cutouts
(partially formed
on underside)
20-689
Mounting Fitting with
8 ft. Copper Lines
(order separately)
20-716
Insulating Back Plate
(order separately)
20-693
6 in. Tube Assembly
with Eyelets
(included with
thermostat)
Cover
(order separately)
20-642
Mounting Ring and
Flathead Screws
(order separately)
Thermostat
Mounting Screws
(included with thermostat)
Figure-8 Surface Mounting of Thermostat,
Pipehead Application.

F-24576-4 ©Copyright 2008 TAC All Rights Reserved. 5
OPERATION
The deadband output (branch) pressure is factory set at
8 psig (55.2 kPa), placing both heating and cooling actuators
in the “off” (or closed) position. The output remains at that
pressure while the ambient (room) temperature varies within
the deadband. When the ambient temperature closely
approaches either the heating orcooling setpoint at eitherend
of the deadband, the output pressure changes at the rate of
approximately 3.3 psi/°F (41 kPa/°C). This modulates the
respective heating orcooling actuator from itsclosed position
toward itsopen position,whilethe otheractuator remains in its
closed position. The temperature sensing assembly,
consisting of a deadband lever and two bimetal elements,
allows onlyone actuatorat a timeto be modulated toward the
open position.
CALIBRATION
Deadband Pressure Calibration
The deadband pressure is factory set at 8 psig. If necessary,
check calibration or adjust this pressure to meet application
requirements, 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 and a suitable gauge into the branch
pressure tap hole (Figure-10 or Figure-11).
2. Be sure ambient temperature is between 65 and 75°F.
Turn the heating dial to 57°F and the cooling dial to 83°F.
3. Adjust the deadband pressure by turning calibrating
screw “A” (see Figure-10 or Figure-11), using a 20-881
thermostat wrench (1/16” hex wrench) until the desired
deadband pressure is obtained.
Setpoint Calibration
Direct-Acting Models
The direct-acting models are calibrated to have a 5.5 psig
branch pressure when the heating dial is set at ambient
temperature, and a 10.5 psig branch pressure when the
cooling dial is set at ambient temperature.
1. Refer to Figure-10. Using a 20-881 thermostat wrench
(1/16” hex wrench), gently turn screw “B” to position the
cooling dial to the 83°F setting. This moves the cooling
bimetal away from the deadband lever. Turn screw “C” to
obtain 5.5 psig output pressure. If there is a difference
between the ambient temperature and the dial reading,
rotate the dial gently to its stop and continue rotating screw
“C”, slipping the screw inside the dial. Rotate the dial back
to again obtain 5.5 psig. If the dial does not match the
ambient temperature, a second try may be required.
Figure-9 Direct-Acting Thermostat Operation.
Thermostat Output Pressure Increase
Heating Heating and
Cooling Off
Dead-Band
(adjustable)
Temperature Increase
Dead-Band Pressure
(factory set at 8 psig)
Dashed lines indicate reverse action.
Cooling
Direct Action

6©Copyright 2008 TAC All Rights Reserved. F-24576-4
2. To calibrate the cooling dial, the heating dial must first be
turned tothe57°Fsetting.Thismovestheheatingbimetal
away from the deadband lever. Turn screw “B” to obtain
10.5 psig. If there is a difference between the ambient
temperature and the dial reading, rotatethe dial gently to
its stop and continue rotating the screw, slipping the
screwinside the dial. Rotate the dial back to again obtain
10.5 psig. If the dial does not match the ambient
temperature, a second try may be required.
3. Position the heating and cooling dials to the desired
setting and replace the cover.
Reverse-Acting Models
The reverse-acting models are calibrated to have a 5.5 psig
branchpressurewhenthecoolingdialispositionedatambient
temperature, and 10.5 psig whenthe heating dial is positioned
at ambient temperature.
To calibrate the reverse-acting models, refer to Figure-11 and
proceed with calibration as outlined under the procedures for
the direct-acting models.
Note: If, for some reason, a thermostat gets completely out
of adjustment and does not respond to the preceding
calibration, first adjust screws “B” and “C” until, by
observation, neither the heating nor cooling bimetals are
touching the deadband lever. Then proceed with the
calibration as outlined.
Calibrating
Screw "C"
Heating
Dial
Heating Setpoint
and Stop Cooling Setpoint
and Stop
Cooling
Dial
Calibrating
Screw "B"
Calibrating
Screw "A"
Branch
Pressure
Tap
Direct-Acting
H
E
A
T
I
N
G
74
72
70
68
66
C
O
O
L
I
N
G
78
76
74
72
70
68
Cooling Bimetal
Heating Bimetal
Dead-Band
Lever
Sensor Ball
Figure-10 Direct-Acting Calibration.
C
O
O
L
I
N
G
68
70
72
74
76
78
H
E
A
T
I
N
G
66
68
70
72
74
Calibrating
Screw "B"
Cooling
Dial
Cooling Setpoint
and Stop Heating Setpoint
and Stop
Heating
Dial
Calibrating
Screw "C"
Calibrating
Screw "A"
Branch
Pressure
Tap
Reverse-Acting
Cooling Bimetal Heating Bimetal
Dead-Band
Lever
Sensor Ball
Figure-11 Reverse-Acting Calibration.

F-24576-4 ©Copyright 2008 TAC All Rights Reserved. 7
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
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-12 Mounting Dimensions.

Copyright 2008, TAC
All brand names, trademarks and registered
trademarks are the property of their respective
owners. Information contained within this
document is subject to change without notice.
F-24576-4
TAC
1354 Clifford Avenue
P.O. Box 2940
Loves Park, IL 61132-2940
www.tac.com