Temperature Controllers
Humidistats 
and 
Thermostats Controllers Sensors Relays Switches Actuators Valves Accessories
Engineering 
Guide
Cross 
Reference
70-6925 35
RP920 Pneumatic Controller
Proportional, high capacity, single or dual input pneumatic 
controller used in conjunction with remote sensors to provide 
proportional (P) or proportional plus integral (P+I) control of 
temperature, humidity, pressure, or dewpoint for heating and air 
conditioning systems. Replacement devices are available for 
Johnson, Powers, Robertshaw, Barber-Colman, and older 
Honeywell controllers.
• Proportional plus integral control option minimizes offset. 
• Miniature diaphragm technology provides high degree of accuracy 
and reliability. 
• Direct Acting models can be converted to Reverse Acting (RA) 
function in field. 
• Field adjustable compensation start point. 
• Local or remote setpoint field option. Integral action cut-off provides 
trouble-free automatic startup. 
• Transparent cover (optional) provides protection while allowing easy 
reading of settings and gages. 
• Corrosion resistant construction.
Dimensions in inches (millimeters) Typical Dual-Input Control System
Typical Single-Input Control System
M17581
RP90A: 1-7/8 (48)
RP920B-D: 3-13/16 (96)
1/8 (3)
MINIMUM
SPACING
BETWEEN 
MODULES
3 (75) MINIMUM CLEARANCE
4
(102)
5-7/8
(148)
3-3/8 (86)
9/32
(7)
RP920A: 1-1/2 (36)
RP920B-D: 3-1/4 (83)
48 9
2
3
1
7
5
6
M
M
(COIL DISCHARGE)
(TEMPERATURE)
PRIMARY
SENSOR
VALVE
N.O.
COMPENSATION
SENSOR (OUTDOOR AIR)
RP920B OR D
C3361-1
0.007 IN.
RESTRICTION
HOT WATER CONVERTER
CONTROL SYSTEM
C87-2
M
24
1
M
CPA
OPTIONAL CPA
MODELS ONLY
RP920A OR C
DA
PRIMARY 
SENSOR IN HW
SUPPLY LINE
N.O.
TO CONVERTER
STEAM
SUPPLY
489
231
M
2
1
4
3
12
3
RP970A
PRIMARY
CONTROLLER
RP920C
489
231
7
IM  5
6
D.A.
1
24
M
489
231
M
LIMIT
CONTROLLER
RP920A
R.A.
FROM
FAN
INTERLOCK
VENT
E-P
RELAY
DAMPER
ACTUATOR
SP970
MINIMUM
POSITION
REGULATOR
OUTDOOR
AIR
RETURN
AIR
PRIMARY
SENSOR
SUPPLY
AIR
MIXED AIR CONTROL SYSTEM