Siemens POWERS Free Energy Band TH 193 HC Technical Instructions

POWERS™ CONTROLS

Technical Instructions

Free Energy Band

®

TH 193 HC

Hesitation Room Thermostat

Document No. 155-069P25

TH 193-5

March 23, 2018

Description

Features

The TH 193 HC Hesitation Thermostats are proportional, single output, dual setpoint,
two-pipe (high air capacity) sensor controllers. Each thermostat includes a wall
mounting plat e for installation in a variety of rough-in terminal box es. Sensitive bimetals
respond to temperature changes to modulate control air through a flapper nozzle. As
the heating load decreases due to internal heat gains, a deadband of control minimizes
energy consumption while the setpoint changes from 72°F (22 °C) heating mode to 78°F
(26°C) cooling mode. Two setpoint dials allow adjustment of the deadband (4°F [2°C]),
minimum). Air connections are made with 5/32-inch (4 mm) O.D. plastic tubing, directly
to the thermostat chassis for retrofit applicati ons, or with plug-in adapters (provided with
the TH 192 rough-in terminal box or optional accessories), which slide into the wall
mounting plate.

• Direct and reverse acting.

• Two separate, adjustable temperature setpoint indicating dials.

• Two highly sensitive bimetal thermostatic elements.

• Fahrenheit or Celsius models.

• Field adjustable deadband output pressure.

• Individual field adjustable sensitivity with graduated scale.

• Integral field adjustable limit stops.

• Control pressure test port accessible without removing cover.

• Easil y replaceable t hermometer, setpoint dials, f ilters and restrictor plate.

• Cov ers av ailable for concealed or exposed therm ometers and for concealed, key,

• St andard plastic thermostat covers provide Desert Beige or white finish.

or exposed knob adjustment and setpoint indication.

Siemens Industry, Inc.

Technical Instructions Free Energy Band TH193 HC Hesitation Room Thermostat
Document Number 155-069P25
March 23, 2018

Optional Design
Features

Application

• Fixed temperature limit stops meet government specifications.

• Met al covers available in standard configurati ons with Desert Beige fi nish.

• Competitor adapter mounting kits available.

• All thermostat chassis availabl e with opt ional 1/2-inch setpoint adjustm ent knobs.

TH 193 HC Hesitati on Thermostats control valve and damper actuators in building
applicati ons that require early morning heat and aft ernoon cooling. TH 193 HC
Hesitation Thermostats control space t emperature and take advantage of the deadband
to "float" room temperature between heating and cooling modes while maintaining
energy management (maximum economy) and occupancy comf ort.

Use TH 193 HC Hesitation two-pipe thermostats where multiple valves and actuat ors,
used with or without high/l ow limiting controls, require higher air capacities. The
thermostats are av ailable with covers that conceal or expose the setpoint adjustment
dials.

Piping

Product Numbers
and Ordering
Information

Chassis

Figure 1. Typical TH 193 HC Hesitation Thermostat Application.

Figure 2. TH 193 HC Hesitation Thermostat Conn ections.

See Table 1 for product num ber and ordering information on TH 193 HC Hesitation
Thermostat chassis.

1. Is a Fahrenheit or Celsius scale required?

2. Is the heat ing and cooling control direct or rev erse acting?

3. Where is the setpoi nt adj ustment knob located?

a. Adjustment knob located at bottom of chassis.
b. Adjustment knob on front with 1/ 2-inch exposed knob.

Page 2 Siemens Industry, Inc.

Free Energy Band TH 193 HC Hesitation Room Thermostat Technical Instructions

Chassis with Wall Plate

Connection

Setpoint

Fahrenheit

Celsius

Document Number 155-069P25

March 23, 2018

Table 1. TH 193 HC Hesitation Thermostat Chassis Part Numbers.

Covers

Type

Hesitation Exposed

Adjustment

Heating and

Cooling DA

Heating and

Cooling RA

Heating and

Cooling DA

Heating and

Cooling RA

193-219 — 193-239 193-240

at Bottom

of Cover

Exposed

193-219K — — —

1/2" Knob

on Cover *

* This f eature requires a key setpoint adjustment cover (or key type cover).

See Table 2.

See Table 2 for product number and ordering information on TH 193 HC Thermostat
covers.

1. Is the setpoint adjustment exposed for customer adjustment or conc ealed to
prevent alt eration of setting?

2. Is the thermometer exposed or concealed?

3. Is the setpoint indication exposed or conc ealed behind the cover?

4. Is a pl astic or zinc cast met al cover required?
a. Plastic covers order 192-2XX.
b. Metal covers order 192-3XX.

5. I s finish of cov er standard or optional? The standard finish color for plastic and
metal covers is Desert Beige.

• For white plastic cov er opti on, add “W” suff ix code to cover part number

(for example: 192-256W). See Table 2.

Siemens Industry, Inc. Page 3

Technical Instructions Free Energy Band TH193 HC Hesitation Room Thermostat

Setpoint

Standard

Optional

Document Number 155-069P25
March 23, 2018

Table 2. TH 193 HC Hesitation Thermostat Cover Part Numbers.

Cover Configuration

Cover Part Number

2

Specifications

Setpoint

Adjustment

Thermometer

Indicator

Plastic Cover

Desert Beige

Metal Cover

Desert Beige

Concealed Concealed Concealed 192-256 192-356

Exposed 192-254 192-354

Key

1

Concealed Exposed 192-267 192-367

Exposed 192-268 192-368

Exposed Concealed 192-258 192-358

Exposed 192-260 —

1 Key setpoint adjustment cover required for all t hermostat chassis with optional

1/2-inch setpoint adjustment knobs.

2 To order a plastic cover with white finish, add suffix code "W".

Control acti on See Table 1.
Operating ranges 45°F to 85°F (7°C to 30°C)
Supply air pressure, maximum 30 psi (207 kPa)
Normal air supply pr essure 18 to 25 psi (124 to 172 kPa)
Sensitivity adjustment 1 to 4 psi/°F (12 to 50 kPa/°C)
Nominal air consumption 40 scim (11 ml/sec)
Deadband

Output Pressure Adjustment 1 to 15 psi (7 to 103 kPa)
Range 0°F to 40°F (0°C to 20°C)

Temperature
Storage temperature -10°F to 140°F (-23°C to 60°C)
Ambient operating temperature 40°F to 140°F (4°C to 60°C)

Temperature response 0.1°F (0.06°C)
Dial graduati ons 2°F (1°C)
Factory setti ngs

Calibration 72°F (22°C) 7.5 psi (52 kPa)
Sensitivity 2.5 psi/°F (31 kPa/°C)
Limit stop adjustment 45°F and 85°F (7°C and 30°C)

Standard cov er Cycolac, desert bei ge
Shipping weight 0.7 lbs. (0.3 kg)
Dimensions See Figure 9.

Page 4 Siemens Industry, Inc.

Free Energy Band TH 193 HC Hesitation Room Thermostat Technical Instructions

Technical Bulletin

Document Number

Document Number 155-069P25

March 23, 2018

Accessories

TH 193 HC FEB
Hesitation
Thermostat Details

See the following Technical Bulletins for information on accessories

TB 237 Terminal Kits
TB 214 Adapter Kits
TB 193 Guard Kit
TB 241 Test Head Kit
TB 167 Restrictors

Figure 3. TH 193 HC Hesitation Thermostat Details.

155-244P25
155-231P25
155-222P25
155-255P25

155-213

Operation

The TH 193 HC Hesitation Thermostat is a two-temperature thermostat with a single
output. In di rect acting control, an increase in temperature increases the control air
pressure, and a decrease in tem perature decreases the control pr essure. I n reverse
acting control, an increase in temperature decreases the control ai r pressure, and a
decrease in temperature increases the control pressure.

The TH 193 HC Hesitation Thermostat provides two separate bimetal elements; one for
heating mode and the other for cooling mode. The setpoint of the two elements
determines the window of the deadband. A 4° F (2°C) minimum deadband is standard,
where the heating mode setpoint is 72°F (22°C) and the cooling mode setpoint is 78°F
(26°C). Fi gure 4 shows a typi cal application with setpoint s adjusted for a 6°F (4°C)
deadband.

Figure 5 shows direct acting TH193 HC hesitation output characteristics. As heati ng
increases, the output pressure increases from 0 to 8 psi (0 to 52 kPa). A field adjustable

deadband occurs. T he deadband spans from 0°F to 40°F (-17°C to 4°C) with a 3 to
15 psi (21 to 103 kPa) output pressure. When the deadband elapses, cooling increases
from 8 to 15 psi (52 to 103 kPa).

Siemens Industry, Inc. Page 5

Technical Instructions Free Energy Band TH193 HC Hesitation Room Thermostat
Document Number 155-069P25
March 23, 2018

Operation,
Continued

Thermometer
Calibration

Deadba n d Output
Pressure Adjustmen t

Figure 4. TH 193 HC Hesitation

Operating Characteristics.

1. Use a test thermometer to read the current room temperature.

2. Pl ace a screwdriver in the cent er of the therm ometer assembly (Figure 3). Caref ully
rotate the thermometer assembly until the pointer tip indicates the correct room
temperature.

NOTE: Avoid breat hing on or touching the bimetal spiral, since this influences the

temperature reading.

Step 1 —

Set the heating dial to minimum
temperature and the cooling dial to
maximum temperature.

Figure 5. TH 193 HC Hesitation

Input/Output Characteristics.

Step 2 —

Adjust the relief valve until the control
pressure is at the deadband output
pressure.

Step 3 —

Set heating and cooling dials to desired setpoints. The deadband is between these two
setpoints.

Page 6 Siemens Industry, Inc.

Free Energy Band TH 193 HC Hesitation Room Thermostat Technical Instructions

Document Number 155-069P25

March 23, 2018

Limit Stop
Adjustment

Sensitivity
Adjustment

Thermostat limit stops define the minimum
and maximum thermostat setpoints. The
limit stops engage in t he 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 the limit stop between
the setpoint cam gear teeth. Rotate the
limit stop to its new position. Do not pull
the limit stop any more than necessary to
clear the gear teeth. Changing the limit
stop position one gear t oot h 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 end

of the

bimetal

element

1 psi/°F

(12 kPa/°C)

Figure 6. Thermostat Limit Stop

Adjustments.

Figure 7. TH 193 HC Hesitation

Sensitivity Adjustment.

NOTE: If the thermostat sensitivity is adjusted,

the thermostat must be recalibrated.

Siemens Industry, Inc. Page 7

Technical Instructions Free Energy Band TH193 HC Hesitation Room Thermostat
Document Number 155-069P25
March 23, 2018

Thermostat
Calibration

Cooling Calibration

The thermostat i s factory calibrated to a control pressur e 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 has changed, or it is out of adjustment, use the following steps to recalibrate
the instrument .

Step 1 —
Remove the cover using the 192-632
Calibration Tool. Verify that the room
temperature is between 70°F and 80° F
(21°C and 27°C).

Step 2 —
Verify that the suppl y pressure is 18
to 25 psi (124 to 172 kPa). Set the
cooling dial to room temperature by
turning the exposed adjustment knob,
or using a hex key as shown. Allow
the thermostat to stand for about five
minutes to adjust to the new setting.

Step 3 —
Rotate the adjustment screw
clockwise to open the relief valve to
maximum. Allow the thermostat to
stand for about five minutes to adjust
to the new setting.

Step 4 —
Moisten the needle and insert the 192­633 Test Gauge and needl e adapter in
the test port. Read the c ontrol
pressure.

Step 5 —
If the control pressure does not read
7 to 8 psi (48 to 55 kPa), turn the
calibration screw using the 192-632
Calibration Tool or 1/8-inch (3.2 mm)
wrench until the pressure is 7 to 8 psi
(48 to 55 kPa). The sensing el ement
is now in calibration and the setpoint
can be changed to the desired r oom
temperature.

Page 8 Siemens Industry, Inc.

Free Energy Band TH 193 HC Hesitation Room Thermostat Technical Instructions

Document Number 155-069P25

March 23, 2018

Heating Calibratio n

Step 1 —

If not already done, remove the cover
using the 192-632 Calibration Tool.
Verify that the room temperature is
between 70°F and 80 °F (21°C and
27°C).

Step 3 —
Moisten the needle and insert the
192-633 Test Gauge and needle
adapter in the test port. Read the
control pressure.

Step 2 —
Verify that the suppl y pressure is 18
to 25 psi (124 to 172 kPa). Set the
heating dial to minimum, and the
cooling dial to maximum temperature
by turning the exposed adjustment
knob, or using a hex key as shown.

Step 4 —
Rotate the adjustment screw
counterclockwise to close the relief
valve until the pressure i s at least 5
psi (35 kPa). Allow the t hermostat to
stand for about five minutes to adjust
to the new setting.

Siemens Industry, Inc. Page 9

Technical Instructions Free Energy Band TH193 HC Hesitation Room Thermostat
Document Number 155-069P25
March 23, 2018

Heating Calibratio n, Continued

Step 5 —

Set the heating dial to room
temperature by turning the exposed
adjustment knob, or by using a hex
key as shown. Allow the thermostat to
stand for about five minutes to adjust
to the new setting.

Troubleshooting

Before troubleshooting thermostat per Table 4, ensure that there is clean, dry supply air
at 18 psi (124 kPa) minimum. Use the test probe gauge and needle adapt er to measure
the control pressure at the thermostat test port.

The output pressure test port is accessible without removing the thermostat cover
through the 8th opening from the top left side for two-pipe thermostats.

Step 6 —
Moisten needle and insert
P/N 192-633 test gauge and needl e
adapter in the test port. Read control
pressure.

Step 7 —
If control pressure does not sho w
required deadband output pressure,
turn calibration screw to obtain this
pressure. Sensing element is now in
calibration.

Figure 8. Accessing Output Pressure Test Port.

Page 10 Siemens Industry, Inc.

Free Energy Band TH 193 HC Hesitation Room Thermostat Technical Instructions

Problem

Check

Cause

Action

Dirt on either supply or

exhaust port on left

Document Number 155-069P25

March 23, 2018

Table 4. Troubleshooting Guide.

Chassis Tube
Connec tor and
Restrictor Plate
Replacement

Control pressure

stays at

approxim ately z ero

Control pressure

stays at

approxim ately

supply pressure

Excessive air
leakage from

side of thermostat

1. Rem ove the thermostat chassis from wall. T he terminal does not have a ball check
valve.

NOTE: You must close off the supply air. For example, use a connector wit h the

supply air terminal plugged.

Air supply Low supply pressure As required

Nozzle or flapper Dirt on nozzle or

flapper

Restrictor Clogged restrictor Replace restri ctor

Calibrati on Out of calibration Recalibrate

Nozzle Clogged nozzle Clean nozzle or

Calibrati on

exhaust valve seat

Supply and return

line connection

Connections are

interchanged or

connection to port is

incorrect

Clean nozzle or

replace therm ostat

replace therm ostat

Alternat ely close and

open nozzle by gently

pushing down the

bimetal

As required

2. Rem ove the two Phill ips head screws f rom the connector on t he back of the thermostat
chassis. Pull t he connect or out of the recess. If necessary, pry the connector loose with
a screwdriver, but be careful not to damage restrictor plate and gasket.

3. Rem ove the gasket from under the connector. Remove the restrictor. Remove the
second gasket from under restrictor.

4. Use the Restrictor Replacement Kit 192-321 t o replace the gasket, restrictor, and
second gasket.

NOTE: The restrictor plate is keyed to ensure proper orientation during installation.

5. Rem ove the filters from the existing connector and insert in new connector. Or, if filters
are dirty, use restr ictor replacement kit P/N 192-321 to replace filt ers.

6. Use the Chassis Tube Connect or Replacement Kit 192-525 to repl ace the connector
and mounting screws.

Siemens Industry, Inc. Page 11

Technical Instructions Free Energy Band TH193 HC Hesitation Room Thermostat

Description

Part Number

Document Number 155-069P25
March 23, 2018

Service Parts

The following chart lists accessory parts and tools available for thermostat service.

Dial thermometer (-40°F to 140°F, -40°C to 60°C) with pocket

141-0573

case
Basic pneumatic calibration kit with therm om eter, gauge, squeeze

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 inch diameter gauge 0-30 psig

192-633

(0-200 kPa) and cali bration/cover wrench
Needle probe, no gauge ( package of five) 192-759
1-1/2 inch diameter gauge , 0-200 kPa,

142-0344

back connected 1/8-inch NPT male
1-1/2 inch diam eter compound gauge, 0-30 psig/0-200 kPa,

142-0373

back connected 1/8-inch NPT male
1-1/2” diameter c om pound gauge, 0-30 psig/0-200 kPa,

142-0426
bottom connected 1/8-inch 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 surf ace mounting), blue

192-487

(package of 20)
Elbow (provides quick return for wall surf ace mounting), white

192-488

(package of 20)

20 scim (5.4 ml/sec) restrictors for one-pipe systems (package
of 5). (1/4-inch, 6.4 mm, O.D. plastic barb unless noted.)

Brass coupling, 1/ 8-i nch NPT (1 only). 184-040
Coupling 184-116
Tee 184-113
Pre-piped dual tee for dual one-pipe systems 184-130

Page 12 Siemens Industry, Inc.

Free Energy Band TH193 HC Hesitation Room Thermostat Technical Instructions

Description

Part Number

Scale Range

Thermostat Model

Document Number 155-069P25

March 23, 2018

Service Parts,
Continued

Replacement t hermometer kits, brown (packages of 5)

45°F to 85°F

192-775

10°C to 30°C 192-776

Model 3 and Up

45°F to 85°F

192-786

10°C to 30°C 192-785

Models 1 and 2

Replacement setpoint dials (packages of 10)

°F, Direct Acting Right Side 192-779
°F, Reverse Acting 192-780
°C, Direct Acting 192-783
°C, Reverse Acting 192-784
°F, Direct Acting Left Side 192-777
°F, Reverse Acting 192-778
°C, Direct Acting 192-781
°C, Reverse Acting 192-782

Dimensions

Figure 9. TH 193 HC Hesitation Room Thermostat Dimensions in Inches

(Millimeters).

Information in this publication is based on c urrent specifications. Th e company reserves the right to make changes in specifications and models as
design i mprovemen ts are intr oduced. POWERS is a trad em ark and F ree Energy Band is a registered tr ademark of Siemens In dustry, Inc . Other
product or company names mention ed herein m ay be the trad emarks of their respective ow ners. © 20 18 Siemens Industry, Inc.

Siemens Industry, Inc.

Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60 089
USA
+ 1 847-215-1000

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Document No. 155-069P25

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Page 13