Page 1
Powers® Controls
TH 192 S Single Temperature
Room Thermostat
Technical Instructions
Document No. 155-065P25
TH 192-1
October 28, 2010
6050 70 80
70
80
TH0355R1
POWERS
Description
Features
Optional Design
Features
The TH 192 S thermostats are proportional single output, single setpoint, 1-pi pe (low air
capacity) or 2-pipe (high air capacity) sensor controllers. Each thermostat includes a
wall mounting plate for installation in a variety of rough-in terminal boxes. A sensitive
bimetal responds to temperature change to modulate control air through a flapper
nozzle. One setpoint dial is provided. Air connections are made with 5/32” (4 mm) O.D.
plastic tubing, directly to the thermostat chassis for retrofit applications or with plug-in
adapters (provided with the TH 192 rough-in terminal box or optional accessories) that
slide into the wall mounting plate.
• Direct and reverse acting models for one- and two-pipe.
• Fahrenheit or Celsius setpoint dials.
• Highly sensitive bimetal thermostatic element.
• Field adjustable sensitivity with graduated scale.
• Integral field adjustable limit stops.
• Control pressure test port accessible without removing cover.
• Easily replaceable thermometer, setpoint dial, filters, and restrictor plate.
• Covers available for concealed or exposed thermometers and for either concealed,
key, or exposed knob adjustment and setpoint indication.
• Standard plastic thermostat covers provide Desert Beige or white finish.
• Fixed temperature limit stops meet government specifications.
• Competitor adapter mounting kits available.
• Metal covers available in standard configurations with Desert beige or white fini sh.
• Some thermostat chassis are available with optional 1/2-inch, large setpoint
adjustment knobs.
Siemens Industry, Inc.
Page 2
Technical Instructions
Document Number 155-065P25
October 28, 2010
Application
TH 192 S thermostats are temperature sensing devices that control pneumatic valve and
damper actuators in heating and cooling applications such as air conditioners, space
heaters, unit ventilators, and air volume controllers. The thermostats maintain energy
management (maximum economy) and occupant comfort. TH 192 S thermostats are
available with covers that conceal or expose the setpoint adjustment dial.
Use TH 192 S 1-pipe thermostats with an external restrictor (20 scim, 5.4 ml/sec) where
a limited air capacity operates a single valve and/or actuator. Use TH 192 S 2-pipe
thermostats where multiple valves and actuators, used with or without high/low limiting
controls, require higher air capacities.
1 - PIPE
EXTERNAL RESTRICTOR
R1
DA
HOT
WATER
N.O. VALVE
CHILLED WATER
TH0242R1
DIAGRAM 1
NOTE: DOTTED LINES ARE ALTERNATIVE CONTROL SCHEMES.
S
N.C. VALVE
1 - PIPE 2 - PIPE
EXTERNAL RESTRICTOR
R1
RA
CHILLED
WATER
N.O. VALVE
HOT WATER
DIAGRAM 2 DIAGRAM 3
S
N.C. VALVE
R1
S
DA
CHILLED
WATER
S
N.C. VALVE
HOT WATER
N.O. VALVE
R1
S
RA
CHILLED
WATER
DIAGRAM 4
2 - PIPE
S
N.O. VALVE
HOT WATER
N.C. VALVE
Figure 1. Typical TH 192 S Thermostat Applications.
Piping
Figure 2. TH 192 S One-Pipe
Thermostat Connections.
Figure 3. TH 192 S Two-Pipe
Thermostat Connections.
Page 2 Siemens Industry, Inc.
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TH 192 S Single Temperature Room Thermostat Technical Instructions
Document Number 155-065P25
October 28, 2010
Product Numbers
and Ordering
Information
Chassis
Adjustment
Exposed
at Bottom
of Cover
Exposed
1/2” Knob
on Cover *
* This feature requires a key setpoint adjustment cover (or key type cover).
See Table 1 for product number and ordering information on TH 192 S thermostat
chassis.
1. Is a one-pipe (low air capacity) or two-pipe (high air capacity) connection required
for application?
2. Is a Fahrenheit or Celsius scale required?
3. Is the control action direct or reverse acting?
a. Direct acting: An increase in temperature increases the control air pressure.
b. Reverse acting: An increase in temperature decreases the control air
pressure.
4. Where is setpoint adjustment knob located?
a. Adjustment knob located at bottom of chassis.
b. Adjustment knob on front with 1/2-inch, large exposed knob.
Table 1. TH 192 S Thermostat Chassis Part Numbers.
Chassis with Wall Plate
Connection
Type
Two-pipe,
relay
One-pipe,
non-relay
Two-pipe,
relay
One-pipe,
non-relay
See Table 2.
Fahrenheit Celsius Setpoint
Direct
Acting
192-202 192-203 192-222 192-223
192-200 192-201 192-220 192-221
192-202K 192-203K 192-222K 192-223K
192-200K — — —
Reverse
Action
Direct
Acting
Reverse
Acting
Siemens Industry, Inc. Page 3
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Technical Instructions
Document Number 155-065P25
October 28, 2010
Covers
See Table 2 for product number and ordering information on TH 192 S thermostat
covers.
1. Is the setpoint adjustment exposed for customer adjustment or concealed to
2. Is the thermometer exposed or concealed?
3. Is the setpoint indication exposed or concealed behind cover?
4. Is a plastic or zinc cast metal cover required?
5. Is finish of cover standard or optional? The standard finish color for plastic and
Table 2. TH 192 S Thermostat Cover Part Numbers.
Setpoint
Adjustment
Key
(See Note 1)
prevent alteration of setting?
a. Plastic covers order 192-2XX.
b. Metal covers order 192-3XX.
metal covers is Desert Beige.
a. For white plastic cover option, add “W” suffix code to cover part number
(for example: 192-256W). See Table 2.
b. For white metal cover option, add "H" suffix code to cover part
(for example: 192-356H). See Table 2.
Cover Configuration Cover Part Number
(See Note 2)
Thermometer
Concealed 192-256 192-356 Concealed
Exposed
Concealed 192-265 192-365
Setpoint
Indicator
Concealed
Exposed
Plastic Cover
Desert Beige
Metal Cover
Desert Beige
192-254 192-354
Exposed 192-266 192-366
Concealed 192-250 192-350 Exposed
Exposed
192-252 192-352
1. Key setpoint adjustment cover required for all thermostat chassis with
optional 1/2” large setpoint adjustment knobs.
2. To order a plastic cover with white finish, add the "W" suffix code. To order
a metal cover with a white finish, add the "H" suffix code.
Page 4 Siemens Industry, Inc.
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TH 192 S Single Temperature Room Thermostat Technical Instructions
Document Number 155-065P25
October 28, 2010
Specifications
Control action See Table 1.
Operating range 45 to 85°F (7 to 30°C)
Supply air pressure, maximum 30 psi (207 kPa)
Normal air supply pressure 18 to 25 psi (124 to 172 kPa)
Sensitivity adjustment 1 to 4 psi/°F (12 to 50 kPa/°C)
Nominal air consumption
One-pipe 25 scim (6.8 ml/sec)
Two-pipe 20 scim (5.5 ml/sec)
Temperature
Storage temperature -10 to 140°F (-23 to 60°C)
Ambient operating temperature 40 to 140°F (4 to 60°C)
Temperature response 0.1°F (0.06°C)
Dial graduations 2°F (1°C)
Factory settings
Calibration @ 72°F (22°C) 7.5 psi (52 kPa)
Sensitivity 2.5 psi/°F (31 kPa/°C)
Limit stop adjustment 45 and 85°F (7 and 30°C)
Standard cover Cycolac, desert beige
Shipping weight 0.7 lbs. (0.3 kg)
Dimensions See Figure 4.
Accessories
Dimensions
See the following Technical Bulletins for information on accessories.
Technical Bulletin
TB 237 Terminal Kits
TB 213 Aspirator Wall Box Kit
TB 214 Adapter Kits
TB 193 Guard Kit
TB 241 Test Head Kit
TB 167 Restrictors
Figure 4. TH 192 S Dimensions in Inches (Millimeters).
Document Number
155-244
155-245
155-231
155-222
155-255
155-213
Siemens Industry, Inc. Page 5
Page 6
Technical Instructions
Document Number 155-065P25
October 28, 2010
Operation
TH 192 S
Thermostat Details
In the TH 192 S direct acting thermostat, an increase in temperature increases the
control air pressure and a decrease in temperature decreases the control pressure.
In the TH 192 S reverse acting thermostat, an increase in temperature decreases the
control air pressure and a decrease in temperature increases the control pressure.
Figure 5. TH 192 S Input/Output Characteristics.
Thermometer
Calibration
Page 6 Siemens Industry, Inc.
1. Use a test thermometer to read the current room temperature.
2. Place a screwdriver in the center of the thermometer assembly (See Figure 6).
Carefully rotate thermometer assembly until pointer tip indicates the correct room
temperature.
NOTE: Avoid breathing on or touching the bimetal spiral since this affects the
temperature reading.
Figure 6. TH 192 S Thermostat Details.
Page 7
TH 192 S Single Temperature Room Thermostat Technical Instructions
Document Number 155-065P25
October 28, 2010
Limit Stop
Adjustment
Sensitivity
Adjustment
Thermostat limit stops define the
minimum and maximum thermostat
setpoints. The limit stops engage in the
setpoint cam gear teeth and cause
interference between the setpoint cam
gear and the adjustment knob gear.
To change limit stop settings, use needle
nose pliers to pull limit stop between the
setpoint cam gear teeth. Rotate limit stop
to its new position. Do not pull limit stop
any more than necessary to clear the
gear teeth. Changing the limit stop
position one gear tooth changes the limit
stop setting by 1-1/3°F (0.7°C).
To change thermostat sensitivity, use a flat-blade
screwdriver to carefully move the sensitivity slide to
the desired position as follows:
Graduation
closest to the
rigid end of
the bimetal
element
4 psi/°F
(50 kPa/°C)
Graduation
closest to the
minimum
(MIN) end of
the bimetal
element
1 psi/°F
(12 kPa/°C)
Figure 7. TH 192 S Limit Stop
Adjustments.
Figure 8. TH 192 S Sensitivity
Adjustment.
Thermostat
Calibration
Siemens Industry, Inc. Page 7
NOTE: If the thermostat sensitivity is adjusted,
the thermostat must be recalibrated.
The thermostat is factory calibrated to a control pressure of 7.5 psi (52 kPa) when the
setpoint and the ambient temperature are both at 72°F (22°C). The factory sensitivity
setting is approximately 2.5 psi/°F (31 kPa/°C). No adjustments are required if these
settings are appropriate for the application. If the thermostat has been tampered with, the
sensitivity changed, or is out of adjustment, use the following steps to recalibrate the
instrument.
Page 8
Technical Instructions
Document Number 155-065P25
October 28, 2010
Step 1 —
Remove cover using 192-632 calibration
tool. Verify room temperature is between 70
and 80°F (21 and 27°C).
Step 2 —
Verify that supply pressure is 18 psi
(124 kPa). Set dial to room temperature by
turning the exposed adjustment knob or
using a hex key as shown. Allow thermostat
to stand for about five minutes to adjust to
the new setting.
Step 3 —
Moisten needle and insert 192-633 test
gauge and needle adapter in a test port.
Read control pressure.
Page 8 Siemens Industry, Inc.
Step 4 —
If control pressure does not read 7 to 8 psi
(48 to 55 kPa), turn calibration screw using
192-632 calibration tool or 1/8” (3.2 mm)
wrench until pressure is 7 to 8 psi (48 to
55 kPa). The sensing element is now in
calibration and the setpoint can be changed
to the desired room temperature.
Page 9
TH 192 S Single Temperature Room Thermostat Technical Instructions
Document Number 155-065P25
October 28, 2010
Troubleshooting
Before troubleshooting thermostat per Table 3, make certain there is clean dry supply air
at 18 psi (124 kPa) minimum. Use test probe gauge and needle adapter to meas ure
control pressure at thermostat test port.
The output pressure test port is accessible without removing the thermostat cover
through the 8th opening from the top. For one-pipe thermostats, the port is on the right
side. For two-pipe thermostats, the port is on the left side.
Figure 9. Accessing Output Pressure Test Port.
Siemens Industry, Inc. Page 9
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Technical Instructions
Document Number 155-065P25
October 28, 2010
Problem Check Cause Action
Control pressure
stays at
approximately zero
Control pressure
stays at
approximately
supply pressure
Excessive air
leakage from
exhaust port on left
side of thermostat
Table 3. Troubleshooting Guide.
Air supply Low supply pressure As required
Nozzle or flapper
Dirt on nozzle or
flapper
Clean nozzle or
replace thermostat
Restrictor Clogged restrictor Replace restrictor
Calibration Out of calibration Recalibrate
Nozzle Clogged nozzle
Clean nozzle or
replace thermostat
Calibration
Dirt on either supply or
exhaust valve seat
Alternately close and
open nozzle by gently
pushing down the
bimetal
Supply and return
line connection
Connections are
interchanged or
As required
connection to port is
incorrect
Chassis Tube Connector
and Restrictor Plate
Replacement
1. Remove thermostat chassis from wall. Terminal does not have a ball check valve.
NOTE: You must close off the supply air. For example, use a connector with the supply
air terminal plugged.
2. Remove two Phillips head screws from connector on back of thermostat chassis. Pull
connector out of recess. If necessary, pry connector loose with a screw driver, but be
careful not to damage restrictor plate and gasket.
3. Remove gasket from under connector. Remove restrictor. Remove second gasket
from under restrictor.
4. Use restrictor replacement kit 192-321 to replace gasket, restrictor, and second
gasket.
NOTE: The restrictor plate is keyed to ensure proper orientation during installation.
5. Remove filters from existing connector and insert in new connector. Or, if filters are
dirty, use restrictor replacement kit 192-321 to replace filters.
6. Use chassis tube connector replacement kit 192-525 to replace connector and
mounting screws.
Page 10 Siemens Industry, Inc.
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TH 192 S Single Temperature Room Thermostat Technical Instructions
Document Number 155-065P25
October 28, 2010
Service Parts
The following chart lists accessory parts and tools available for thermostat service.
Table 4. Service Parts.
Description Part Number
Dial thermometer (-40 to 140°F, -40 to 60°C) with pocket case
Basic pneumatic calibration kit with thermometer, gauge, squeeze
141-0573
832-177
bulb, fittings, and case
Test head kit 832-179
Calibration tools 832-178
Test probe to check pressure with cover on
Needle probe with 1-1/2” diameter gauge 0-30 psig
192-633
(0-200 kPa) and calibration/cover wrench
Needle probe, no gauge (package of five) 192-759
1-1/2” diameter gauge , 0-200 kPa,
142-0344
back connected 1/8” NPT male
1-1/2” diameter compound gauge, 0-30 psig/0-200 kPa,
142-0373
back connected 1/8” NPT male
1-1/2” diameter compound gauge, 0-30 psig/0-200 kPa,
142-0426
bottom connected 1/8” NPT male.
Replacement for use with 192-633
Chassis tube connector replacement kit with mounting screws
192-525
(material for 10 thermostats included)
Restrictor plate replacement kit with filters and gasket
192-321
(material for 10 thermostats included)
Plug-in adapters for quick thermostat removal
Straight, blue (package of 20) 192-485
Straight, white (package of 20) 192-486
Air link connects adapters for pressure tests (package of 20) 192-501
Compression ring (package of 100) 141-388
Elbow (provides quick return for wall surface mounting), blue
192-487
(package of 20)
Elbow (provides quick return for wall surface mounting), white
192-488
(package of 20)
20 scim (5.4 ml/sec) restrictors for 1-pipe systems (package of 5).
(1/4 “, 6.4 mm, OD plastic barb unless noted.)
Brass coupling, 1/8” NPT (1 only). 184-040
Coupling 184-116
Tee 184-113
Pre-piped dual tee for dual 1-pipe systems 184-130
Siemens Industry, Inc. Page 11
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Technical Instruction
Document No. 155-065P25
October 28, 2010
Service Parts
(Continued)
Table 4. Service Parts (Continued).
Description Part Number
Replacement thermometer kits, brown (packages of 5)
Scale Range Thermostat Model
45° to 85°F
192-775
10° to 30°C
TH0443R1
192-776
Model 3 and Up
45° to 85°F
192-786
10° to 30°C
TH0442R1
192-785
Models 1 and 2
Replacement setpoint dials (packages of 10)
°F, Direct Acting 192-779
°F, Reverse Acting 192-780
Right Side
°C, Direct Acting 192-783
°C, Reverse Acting
°F, Direct Acting 192-777
°F, Reverse Acting 192-778
°C, Direct Acting 192-781
Left Side
°C, Reverse Acting
192-784
192-782
Information in this publication is based on current specifications. The company reserves the right to make changes in specifications and models as
design improvements are introduced. Powers is a registered trademark of Siemens Industry, Inc. Other product or company names mentioned
herein may be the trademarks of their respective owners. © 2010 Siemens Industry, Inc.
Siemens Industry, Inc.
Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089
USA
+ 1 847-215-1000
Your feedback is important to us. If you have comments
about this document, please send them to
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Document No. 155-065P25
Printed in the USA
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