Install Instructions
TP970-72, TP970-74, TP9600, AND TP9630 PNEUMATIC SENSORS, HUMIDISTATS, AND THERMOSTATS
% rh
Output Pressure in psi (kPa)
Range:
15 to 75%
15 to 85%
HP971A1024* 65 to 95%
15 3.0 (21) 3.0 (21) —
20 3.5 (24) 3.9 (27) —
25 4.2 (29) 4.7 (32) —
30 4.9 (34) 5.6 (39) —
35 5.8 (40) 6.4 (44) —
40 6.8 (47) 7.3 (50) —
45 7.8 (54) 8.1 (56) —
50 8.9 (61) 9.0 (62) —
55 10.0 (69) 9.9 (68) —
60 11.1 (77) 10.7 (74) —
65 12.3 (85) 11.6 (80) 3.0 (21)
70 13.6 (94) 12.4 (85) 4.0 (28)
75 15.0 (103) 13.3 (92) 5.3 (37)
80 — 14.1 (97) 7.5 (52)
85 — 15.0 (103) 10.3 (71)
90 — — 13.1 (90)
95 — — 15.0 (103)
* Has a 0.007-in. restriction, and a 0.05-in. bleed restriction in
output line.
7. Readjust calibration screw slowly until pressure is
correct ±0.5 psi for the measured ambient humidity.
8. Remove Gage and replace cover.
Thermostat/Temperature Sensor
General
After installing the thermostat, set the thermostat to the desired
setpoint and let the system operate long enough to stabilize.
The length of time required for stabilization depends on system
response time and could be only a few minutes or as long as
several hours. Verify that the system has stabilized before
checking calibration.
NOTE: Thermostats and temperature sensors are factory
calibrated and should require only a bleed-off check to
ensure correct operation. The throttling range is factory
set and should not require adjustment under normal
operating conditions.
Figure 50 shows thermostat components.
GAGE TAP
BIAS SPRING
757065 80 85 90 95
SETPOINT
LOCKING STOPS
SETPOINT
ADJUSTMENT
ELEMENT
THROTTLING
SPRING
RANGE
ADJUSTMENT
THROTTLING
RANGE SCALE
SETPOINT
SCALE PLATE
INDICATOR
CALIBRATION
SCREW
NYLON
ELEMENT
SETPOINT
LOCK SCREW
C3945
Throttling Range Adjustment
1. Use Thermostat Tool to remove cover. Assemble Gage
and Gage Port Needle.
2. Insert Gage Port Needle in thermostat gage tap.
3. Slide throttling range (TR) adjustment to desired
position on TR scale.
4. Mechanically check TR by moving setpoint indicator to
determine difference in setpoint indication when
branchline pressure reads 3 psi (21 kPa) and 13 psi
(91 kPa).
NOTE: If required, turn calibration screw to adjust TR into
thermostat range.
5. Reset TR to within ±2 degrees F (±1 degrees C) of
required setting.
6. Follow applicable procedure under CALIBRATION
CHECK.
Calibration Check
Direct-Acting Thermostat
1. Use Test Thermometer to measure actual temperature
of space.
2. Turn setpoint indicator down to 5 degrees F (2.8 degrees
C) below room temperature.
3. Wait 5 to 10 seconds (30 to 60 seconds for TP973) to
allow thermostat to build up branchline pressure.
4. Turn setpoint indicator up slowly.
5. If thermostat begins to bleed off between 1 degree F
(0.6 degrees C) and 3 degrees F (1.7 degrees C) below
room temperature, no recalibration is necessary. If
recalibration is needed, see RECALIBRATION.
Reverse-Acting Thermostat
1. Use Test Thermometer to measure actual temperature
of space.
2. Turn setpoint indicator up to 5 degrees F (2.8 degrees
C) above room temperature.
3. Wait 5 to 10 seconds (30 to 60 seconds for TP973) to
allow thermostat to build up branchline pressure.
4. Turn setpoint indicator down slowly.
5. If thermostat begins to bleed off between 1 degree F
(0.6 degrees C) and 3 degrees F (1.7 degrees C)
above room temperature, no further calibration is
necessary. If recalibration is needed, see
RECALIBRATION.
Recalibration
The procedures in this section assume that a calibration
check has been performed (see CALIBRATION CHECK) and
that the thermostat has not operated correctly.
NOTE: Thermostats have either an adhesive paper dot or
an antihum spring, as shown in Figure 50. Verify that
either the adhesive paper dot is in place or the
antihum spring just touches the throttling plate and is
not wedged against it. If the antihum spring needs
adjustment, see TP970 Series Pneumatic
Thermostats Service Data 75-7134.
CAUTION
Excessive handling during calibration can heat the
thermostat and cause an inaccurate reading.
Fig. 50. Thermostat Front View, Cover Off.
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