Honeywell RP908A Series Service Data page 7

REPAIR
RP908 DISASSEMBLY PROCEDURES
remove Cover (Fig. 9, Part 1).
the Backplate, and move Controller to a bench,
If replacing the CPA Seal, it is necessary to do this
while the Bracket is attached to the Body It is very
easy to rip the CPA Seal if the Setpoint Screw
Assembly is loose. See Step 15, CPA Models.
Remove the four Screws securing the Bracket to the
Body (Fig. 9, Part 2).
4. Remove the four Screws securing the Manifold (Fig.
9, Part 3).
5. Lift the Manifold from the Body.
6. Remove and discard the Gasket, if replacing.
Note the location of the Filters and Restriction(s),
The RP908A may have two or three Filters (depend-
ing on model), and the RP908B may have three or
four Filters. Some Controllers may have a field-
installed Blank Orifice in place of a Restriction, Fil-
ter, Screen, and Washer. If this Blank Orifice is
required, the job drawing will show a box drawn
around the port of the RP908 to be blocked.
NOTE: Serviceline Repair Kit 14002696-001 is
available for order. This kit contains one
Gasket, four O-Rings, four Screens, two
Restrictions, four Filters, and four
Washers
8.
Remove the Washers, Filters, Screens, Restriction,
and O-Rings, if replacing, and discard.
9. Remove Blank Orifice, if installed. Install replace-
ment parts in reverse order,
For Body repair, first disconnect the Bias Spring and
the two Reverse Acting Springs at the lower attach-
ment point.
Remove the two Pivot Screws securing the Lever
Assembly to the Body. Set Lever Assembly and
Screws aside.
12.
Remove the two Screws securing Upper Lever
Assembly. Set Upper Lever Assembly and Screws
aside.
13. Remove the two cross-head Screws from the Cover
Assembly to replace any parts in the Cover
Assembly,
14.
For replacement of the Proportional Band Adjust-
ment Knob, simply unscrew from the Indicator
Assembly.
15.
Non-CPA Models:
Remove the Setpoint Knob (Fig. 9, Part 4). The Set-
point Spring, Setpoint Nut, and Setpoint Screw will
then come right out.
CPA Models:
a. Loosen the two cross-head Screws and remove the
CPA Housing (Fig. 9, Part 4), Carefully remove
the Seal while the bracket is still attached to the
Body. The Seal should be removed and then the
Bracket detached from the Body to remove the
point Screw Assembly.
b. Remove the two cross-head Screws from the end
of the Authority Adjustment Lever Assembly.
Remove the two Screws from the front and back
of the Bracket to remove the Body Assembly that
is situated over the Authority Adjustment Lever
Assembly.
Assemble RP908 in reverse order and turn on system
air.
17.
Make all Settings and Adjustments applicable to
model according to job drawings. Perform Opera-
tional Check and Calibrate (see MAINTENANCE
section).
REPLACEMENT OF RESTRICTION
The Internal Restriction must be replaced with a
Blank Grifice when the sensor is supplied with an
external source of restricted air, This occurs when the air
supply to the M Port of the Controller is varied by other
controls, or when a single sensor is connected to more
than one Controller. To replace the Restriction with a
Blank Orifice, proceed as follows, referring to Figure 9,
Part 3.
1. Remove the Manifold and Gasket.
2. Remove the Port 1 O-Ring, Restriction, Screen,
Filter, and Washer. Install Blank Orifice 316125.
3. Reassemble the O-Ring, Gasket, and Manifold,
carefully noting orientation of the Gasket,
When using only one port of an RP908B and the
Restriction is not blocked, do not plug the unused port
but leave it open to avoid building up to mainline pres-
sure in the sensor chamber. Two limit models of the
Orifice identified by a red Manifold. When field install-
ing a Blank Orifice, the Manifold and job drawings
should be marked, indicating that the Restriction is
blocked.
75-553 1