Honeywell RP908A 1005, Service Data

Page: 1 / 14

GENERAL
DESCRIPTION
The RP908A and B are force balance pneumatic
amplifiers, with adjustable proportional band, for use as
Controllers in HVAC systems,
The RP908 is no longer being manufactured. There is
an RP920 model available for all RP908A and B applica-
tions. Refer to Application Replacement Listing in the
REPAIR section.
APPLICATION
RP908A
RP908A & B
PNEUMATIC CONTROLLERS
The RP908A, in conjunction with a remote sensor,
provides direct or limit control in air conditioning con-
trol systems, with or without remote control point
adjustment (CPA). It may be adjusted for either direct or
reverse acting operation. Refer to Figures 1 and 2 for
these applications.
PRIMARY LOW
CONTROLLER CONTROLLER
5759-2
Fig. 2. Typical RP908A Low Limit Control.
RP908B
5737-2
The RP908B dual input Controller is applied to com-
pensating systems by using an additional compensating
Fig. 1. Typical RP908A Primary Control of Normally
Open Valve.
signal to change the control point of the Controller (Fig.
3). Temperature, humidity, pressure, or dewpoint may
be controlled by using the appropriate sensors,
Rev. 6-84
Form No
Commercial Group
MLFTAB: C. 6.