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Technical Instructions 
Document Number 155-067P25 
October 28, 2010 

Page 8

 

Siemens Industry, Inc. 

 

Changeover Point 
Adjustment, 
Continued 

 

Figure 7.  Changeover Point Adjustment.  

Limit Stop 
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). 

 

Figure 8.  TH 192 DN and DNV 

Limit Stop Adjustments.  

Sensitivity 
Adjustment 

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) 

 

NOTE: 

If the thermostat sensitivity is adjusted, 
the thermostat must be recalibrated.  

Figure 9.  TH 192 DN and DNV 

Sensitivity Adjustment.  

Summary of Contents for TH 192 DN

Page 1: ...ions or with plug in adapters provided with the TH 192 rough in terminal box or optional accessories which slide into the wall mounting plate Features Direct and reverse acting for day and night modes DN models Two separate adjustable temperature setpoint indicating dials Two highly sensitive bimetal thermostatic elements Operating mode automatically switches from day to night on change of main ai...

Page 2: ...n evenings and weekends to reset the control system to the night mode ensures optimum energy management When a zone is operating in maximum economy mode at night an occupant can reset an individual space to day temperature by switching a manual override During night control the TH 192 DNV provides a separate output signal full air supply which allows ventilation to occur TH 192 DN DNV thermostats ...

Page 3: ...upply output signal required for ventilation control 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 2 TH 192 DN DNV Thermostat Chassis Part Numbers Chassis with Wall Plate Fahrenheit Celsius Connection Type Control Action Exposed at Bottom of Cover Exposed 1 2 Knob on Cover Exposed at Bott...

Page 4: ...e plastic cover option add W suffix code to cover part number for example 192 256W See Table 2 a For white metal cover option add H suffix code to cover part for example 192 356H See Table 3 Table 3 TH 192 DN DNV Thermostat Cover Part Numbers Cover Configuration Cover Part Number See Note 2 Setpoint Adjustment Thermometer Setpoint Indicator Standard Plastic Cover Standard Metal Cover Concealed 192...

Page 5: ...0 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 See the following Technical Bulletins for informatio...

Page 6: ...anual Selector Switch A manual selector switch allows an individual thermostat to control at its day setting even though the remainder of the system is controlling at its night setting In the normal AUTO position the manual selector switch does not interfere with air passage to the changeover relay To manually set the selector switch to the DAY position push the selector in until it latches and th...

Page 7: ...n 14 and 22 psi 96 and 152 kPa 1 Connect pressure gauge or manometer to measure supply pressure to thermostat Use 30 psi 207 kPa supply through a positioning switch so pressure can be fully variable 2 Determine current change over point Turn day dial so day and night control pressures are different Then note the changeover point on the control gauge as the supply pressure changes 3 Remove thermome...

Page 8: ...th 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 Figure 8 TH 192 DN and DNV Limit Stop Adjustments Sensitivity Adjustment To change thermostat sensitivity use a flat blade screwdriver to carefully move the sensitivity slide to the desired po...

Page 9: ...alibrate the instrument Day Time Calibration 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 daytime 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 Moi...

Page 10: ...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 the test port Read control pressure 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...

Page 11: ...ing Output Pressure Test Port Table 4 Troubleshooting Guide Problem Check Cause Action 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 Control pressure stays at approximately zero Calibration Out of calibration Recalibrate Nozzle Clogged nozzle Clean nozzle or replace thermost...

Page 12: ...placement kit 192 321 to replace filters 6 Use chassis tube connector replacement kit 192 525 to replace connector and mounting screws Service Parts The following chart lists accessory parts and tools available for thermostat service Description Part Number Dial thermometer 40 to 140 F 40 to 60 C with pocket case 141 0573 Basic pneumatic calibration kit with thermometer gauge squeeze bulb fittings...

Page 13: ... 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 package of 20 192 487 Elbow provides quick return for wall surface mounting white package of 20 192 488 20 scim 5 4 ml sec restrictors for 1 pipe systems package of 5 1 4 6 4 mm O D plastic barb unless noted Br...

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