80-4280-10, Rev. 4
MAINTENANCE
42
DCM-2 REPLACEMENT (cont’d)
REQUIRED TOOLS
FOR ALL MODELS
1/2” socket wrench
Torque wrench (appropriate for 10 lb-ft)
Communications device for calibration
Additional Tools for Model 22-309
#3 Phillips head screwdriver
Torque screwdriver with #3 Phillips head bit
(appropriate for 50 lb-in)
Additional Tools for Model 22-409
7/16” hex socket wrench
Torque wrenches
(appropriate for 50 lb-in and 10 lb-ft)
CAUTION
To prevent electrostatic discharge
damage to the electronics, wear
a grounding strap during this
procedure.
PROCEDURE
DCM-2 chassis assembly diagrams and the
Group 22 operating parameter table (Table 2) are
provided to help you identify the components and
parameters referenced in the following directions.
The DCM-2 is located in the DCM
Compartment. Loosen the (4) captive
5/16-18
x 1.75” mounting screws and remove
the DCM Compartment cover.
The new DCM-2 operating parameters
should be configured to match the existing
DCM settings. The Group 22 operating
parameter table (Table 2 - page 41) lists
some of the settings in approximate order
of importance and shows the factory default
configuration.
The most commonly changed parameter
is the actuator rotation direction. The actuator
can be configured for clockwise or counter-
clockwise rotation on increasing Demand
signal (usually the rotation from closed to
open). This direction should be referenced
by facing the output shaft side of the actuator.
If replacing an older DCM-H (HART®
interface) or DCM-2 and HART® communication
is still possible, read and record the values
listed in Table 2. These values can be obtained
through a HART® handheld communicator or a
HART® capable control system. Refer to the
HART® appendix for additional information on
handheld communicator connection and DD menu
structure.
If replacing an older DCM-L (Local interface)
and serial communication is still possible, read
and record the values listed in Table 2. These
values can be obtained through the DCM serial
port using the Beck serial commands. It is possible
to obtain this information from the serial port on
DCM-H and DCM-2 chassis as well if HART is
not available. Refer to the serial port appendix
for additional information on serial port connection
and commands.
WARNING
WARNING
Electrical shock hazard. Disconnect
power before proceeding. Remove
the actuator from line voltage and
disconnect any external power
sources feeding the auxiliary switches.
Remove the DCM assembly:
1. Place the Handswitch in STOP.
2. Ensure power to the actuator has been
disconnected.
3. Disconnect the (5) wiring connectors shown in
the appropriate DCM-2 chassis illustration on
the following page.
4.
For 22-309
:
While holding the DCM handle,
loosen the (4) captive mounting screws with a
#3 Phillips head screwdriver. Go to Step 5.
OR
For 22-409
:
Loosen the (6) hex mounting
screws with a 7/16” socket wrench.
5. Using the handle, remove the DCM-2 chassis
from the DCM Compartment.
Install the new DCM assembly:
1. Position the new DCM-2 in the DCM
Compartment.
2. Align the locating pin holes in the DCM with the
pins in the rear wall of the DCM Compartment
as the DCM is seated.
3.
For 22-309
:
While pushing the DCM back
on its mounting surface, tighten the captive
mounting screws with a #3 Phillips head bit.
Torque to 50 lb-in (5.6 N•m). Skip to step 4.
OR
For 22-409
:
While pushing the DCM back
on it’s mounting surface, tighten the (6) hex
mounting screws with a 7/16” socket wrench.
Torque to 50 lb-in (5.6 N•m).
