RP920A,B,C,D MODULAR PNEUMATIC CONTROLLERS
2. Install a 0 to 30 psi (0 to 207 kPa) gage in BLP test tap
or in BLP gage port if one is not permanently installed.
3. Apply MLP to the system.
4. Adjust the authority knob to minimum.
5. Adjust the compensation startpoint knob until the
receiver gage (port 5) reads the pressure equivalent of
the compensation startpoint (W
c
) (Fig. 9 or 10).
6. If the compensation startpoint (W
c
) and desired
startpoint do not match, remove the knob and replace it
so they do match.
7. The compensation startpoint (W
c
) is now calibrated.
NOTE: The response of the receiver gage may be
slow (up to one minute). The controller is not
defective under these conditions.
17. Remove the CCT816B Calibration Unit and pipe
sensors.
RP920C and D Systems
1. Remove the integral module screw (Fig. 13) and install
the 14003755-001 Barb Fitting and O-ring in its place.
2. Apply 8 psi (55 kPa) to the integral module.
3. Calibrate the RP920:
a. RP920C: follow the procedure for the RP920A.
b. RP920D: follow the procedure for the RP920B
except that the calibration value of the BLP for
Steps 10 and 15 should both be 8 psi (55 kPa).
4. When calibration is complete, remove the barb fitting
from the integral module and replace the screw.
8. Set up the CCT816B Calibration Unit (Fig. 11) to
connect to port 3 (primary sensor).
NOTE: Sensors are not connected.
FULL
COMP
SETPOINT
(W 1)
COMPENSATION
STARTPOINT (Wc )
C5110
COMPENSATION SENSOR
Fig. 9. Negative compensation calibration reset schedule.
C5109
PRIMARY SENSOR
THE GAGE RANGE MUST
4
8
9
7
5
MATCH THE RANGE OF THE
SENSOR FEEDING PORT 5
2
3
1
6
M
PRIMARY
SENSOR
Fig. 8. Piping for RP920B compensation
startpoint (W
c
) setting.
9. Apply a pressure equivalent of the primary sensor value
corresponding to the compensation start (comp start) on
the reset schedule (Fig. 9 or 10).
10. Adjust the setpoint knob until the BLP equals the
expected pressure of the controlled device at comp start
conditions.
11. If needed, remove the setpoint knob and replace it
so the setpoint matches the primary sensor value at
comp start.
12. The setpoint (W
1
) is now calibrated.
13. Set up the CCT816B Calibration Unit (Fig. 12) to
connect to port 3 (primary sensor) and port 5
(compensation sensor).
14. Apply sensor input pressures equivalent to the full
compensation on the building schedule.
15. Adjust the authority (A
c
) knob until the BLP equals the
expected pressure of the controlled device at full
compensation conditions.
16. Calibration is complete.
IMPORTANT
PRIMARY SENSOR
FULL
COMP
SETPOINT
(W1 )
COMPENSATION
STARTPOINT (Wc )
COMPENSATION SENSOR
C5111
Fig. 10. Positive compensation calibration reset schedule.
RP920B Calibration Example
Assume the following conditions:
— A 10°F (5.6K) throttling range.
— Using a 2.5 to 6.5 psi (17 to 45 kPa) operator with a
normally open (N.O.) valve where conditions are: 6.5 psi
(45 kPa) with no load and 2.5 psi (17 kPa) with full load.
— See Fig. 14 for the schedule graph.
— See Table 2 for the reset schedule.
Table 2. Reset Schedule.
Changing compensation startpoint (W
c
) or setpoint
(W
1
) affects only the one corresponding value of the
reset schedule, while changing authority (A
c
) affects
only the slope of the reset schedule.
NOTE: See the Compensation Startpoint (W
c
)
Adjustment section for more information.
Compensation
Range
Primary Sensor
(Discharge)
Compensation
Sensor (OA)
Start
120°F (49°C) (40%)
60°F (16°C) (50%)
Full
160°F (71°C) (60%)
0°F (-18°C) (20%)
Operating Span 40°F (22K)
60°F (33K)
Sensor Range
40 to 240°F
(4 to 116°C)
-40 to 160°F
(-40 to 71°C)
5
95-7392EF