Inspection And Cleaning; Operational Check; All Systems; System In Operation - Honeywell RP920A-D Service Data

INSPECTION AND CLEANING

Occasionally, check for leaks and loose fittings and
screws. Especially check the self-tapping screw in Port 8
and the self-tapping screw at the top of the integral module
(RP920C and D).
NOTE: Once removed, self-tapping screws can be a
source of air leakage because of a damaged 0­
ring. Check the O-ring and replace it if it is
damaged,
Use a soft cloth or brush to remove accumulated dust and/
or dirt from th e RP920.

OPERATIONAL CHECK

ALL SYSTEMS

Be certain all adjustment settings and conditions are
correct. See job drawing s for
of the adjustments available on each model.
Table 1 . RP92 0 Adjustments.
Adjustment
X
Proportional Band
X
Internal restrictor
X
switch
Direct/reverse acting X
(proportional
module position)
I
Authority
Positive/negative
compensation (switch
block module position
Reset time
Gage/integral cut-off
(switch block gasket

SYSTEM IN OPERATION

Be certain th eHVAC equipment is functional.
Observe BLP. If it is not between 3 and 13 psi (21 to
90 kPa) , slowly adjust th e setpoin t knob and/or CPA
until the BLP is in the 3 to 13 psi (21 to 9
Allow the system to stabilize before continuing.
Measure the temperature, humidity, or static pressure
at the main sensor. This should agree with th
throttling range .
of the
measurement should agree with the reset schedule
prope r
settings. Table 1 is a list
Model
X X X
X X X
I Xl X I X
X X X
I I
X
X X
X X
0 kPa ) range.
setpoint e
For theRP920B and Dthe
of the throttling range as set by the authority and
compensation startpoint. If a discrepancy exists,
recalibrate the controller.
4. Move th e setpoin t slightly up and down. The BLP
should change proportionally in the same direction
for direct acting and in the opposite direction for
reverse acting controllers. Repeat this step using the
CPA if applicable. If the BLP responds properly, the
controller is good. Return th e setpoin t and CPA to the
original settings,
NOTE: The RP920C or D should maintai n
closer to th e setpoin t or reset schedule than
the RP920 A or B because of the integral
action.
SYSTEM NOT OPERATING-SENSORS
DISCONNECTED

EQUIPMENT

0- to pressure gage.
Restricted air supply, adjustable from 3 to 15 psi (21
to 10 3 kPa) , with receiver gage to match sensors or
Sensor Controller Calibration Ki t MQP816A.
Pneumatic Calibration Kit MQP80 0 (optional).
PROCEDURE
1. Connect the 0- t o 30-psi gage to Port 2 (branch).
2. Connect the main air supply to Port 1 (18 psi
minimum).
3. Pipe a 3 to 15 psi (21 to 10
supply with a receiver gage which matches the
primary sensor to Port 3.
4.
Pipe a second 3 to 15 psi (21 to 10
air supply with a receiver gage which matches the
compensation sensor to Port 5 of an
5. If checking a CPA model, pipe 9 psi to (62
Port 9. The
supply 9 psi (62
6. On an
screw from the integral module (Fig. 12) and install
Barb Fitting 14003755-001 in its place. Apply 8 psi
(55 to the integral module. This prevents
integral action. Without this procedure, it is
necessary to allow additional time for the controller
to finish responding to any change in input pressure
or settings.
and
a . Adjust the input air pressure to Por 3t t o
correspond with the mid-point of the throttling
range of the primary sensor (see APPENDIX
A).
5
kPa ) adjustable air 3
kPa ) adjustable 3
or can be used to
and D, remove and save the seal
control
or D.
to
85-O 142