TH 192 DN Day-Night and DNV Day-Night-Vent Room Thermostat
Technical Instructions
Document Number 155-067P25
October 28, 2010
Siemens Industry, Inc.
Page 7
TH 192 DN and DNV
Thermostat Details
Figure 6. TH 192 DN and DNV Thermostat Details.
Thermometer
Calibration
1. Use a test thermometer to read the current room temperature.
2. Place a screwdriver in the center of the thermometer assembly (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 influences the
temperature reading.
Changeover Point
Adjustment
The changeover point is factory set to occur between 19 and 22 psi (131 and 152 kPa).
The changeover point can be field adjustable to occur between 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 thermometer for access to changeover adjust screw. Use a 1/16" Allen Hex
Key to adjust changeover adjust screw as follows:
a. If changeover is too high, turn off supply pressure and rotate changeover adjust
screw clockwise. One turn decreases changeover point by about 3 psi (20 kPa).
Turn on supply pressure and recheck to verify new changeover point.
b. If changeover is too low, turn off supply pressure and rotate changeover adjust
screw counterclockwise. One turn increases changeover point by about 3 psi
(20 kPa). Turn on supply pressure and recheck to verify new changeover point.
