Bard CMA-40 Owner's manual

Page 1 of 4
The purpose of the CMA-40 kit is to allow the
addition of sensors for connection to a DDC control
system. These sensors include a dirty filter switch, a
discharge air sensor, an airflow verification switch and a
compressor current sensor.
The CMA-40 kit is for use with Bard models W18-36AB
wall-mount air conditioners. NOTE: This kit is not
intended for units with mechanical dehumidification.
Component mounting locations as depicted in these
instructions will encounter obstructions if attempting to
install on units with dehumidification.
The CMA-40 consists of field-installable sensors for use
with DDC control systems. The CMA-40 includes:
• 7960-849 Supplemental Instructions
• 910-1894 Airflow Switch Assembly
• CMC-31 Dirty Filter Switch Kit
• 910-1223 Compressor Current Sensor
• 910-1224 Discharge (Supply) Air Sensor
• 8607-021 Low Voltage Terminal Board
• 7961-837 Terminal Board Label
• 8611-033 7/8" Snap Bushing (2)
• 1012-065 Phillips Head Screw (6)
• 1012-086 Hex Head Screw (8)
• 7961-312-0483 CMA-40 Unit I.D. Label
Field-supplied tools needed:
• Personal protection equipment, including gloves
and safety glasses
• 5/16" nut driver
• Phillips head screwdriver
• Small flat head screwdriver for securing wire in
terminal blocks
NOTE: Low ambient kit required for Balanced Climate
and compressor operation below 60º F (sold separately).
Bard Manufacturing Company, Inc.
Bryan, Ohio 43506
www.bardhvac.com
Manual: 7960-849
Supersedes: NEW
Date: 9-17-19
CMA-40 DDC Sensors
SUPPLEMENTAL INSTRUCTIONS
Sharp metallic edges.
Take care and wear appropriate protective
devices to avoid accidental contact with
sharp edges.
Failure to do so can result in personal
injury.
!CAUTION
Exposed moving parts.
Disconnect all electrical power before
servicing.
Failure to do so can result in severe injury
or amputation.
!WARNING
Electrical shock hazard.
Disconnect the remote electric power
supply or supplies before servicing.
Failure to do so can result in serious injury
or death.
!WARNING

Manual 7960-849
Page 2 of 4
Installation
1. Disconnect all power to wall mount before
installing sensors.
2. Remove inner and outer control panel covers.
Remove electric heater access panel, service panel
and blower access panel.
3. Install the airflow switch assembly using two (2)
hex head screws. Use the holes in the blower
partition shown in Figure 1.
4. Route the wires into the control panel.
5. Install the filter switch assembly. Refer to 7960-
853 instructions provided with the CMC-31 kit.
AIRFLOW SWITCH
MOUNTING HOLES
MIS-4077 A
WIRES FROM BOTH AIR FLOW
AND DIRTY FILTER SWITCH ARE TO
BE ROUTED DOWN AND THROUGH
THIS HOLE IN CONTROL PANEL
AIRFLOW
SWITCH ASS'Y
AIRFLOW SWITCH ASS'Y
IS TO BE MOUNTED WITH
TWO SCREWS IN BLOWER
PARTITION
FIGURE 1

Manual 7960-849
Page 3 of 4
6. Route the filter switch wires into the control panel.
7. Remove screw from the electric heater bracket (see
Figure 2).
8. Install the discharge (supply) air sensor using the
screw removed in Step 7 and one (1) additional
hex head screw supplied with kit.
9. Route the discharge air sensor wires into the
control panel through the electric heat wire chase
as shown in Figure 3.
10. Remove the black wire from the compressor
contactor (see Figure 3).
11. Route the wire through the hole in the current
sensor and reconnect wire.
12. Mount the current sensor to the control panel.
13. Route the current sensor wire, airflow switch wire,
filter switch wire and discharge air sensor wire into
the low voltage box.
14.
Attach wires to the terminal board according to the
wiring diagram. See Figure 3 and Figure 4 (page 4).
15. Carefully push wires into the low voltage box and
install terminal board using two (2) phillips head
screws (see Figure 5 on page 4).
MIS-3772 A
GY
BOX & CONNECT
ACCORDING TO
O
O
Y
Y
GY
WIRE DIAGRAM
PK
T
ROUTE WIRES
INTO LOW VOLTAGE
APPLY (2) BUSHINGS
LEFT HAND UNITRIGHT HAND UNIT
1
FROM CONTACTOR
HOLE INSENSOR AND
ROUTE WIRE THROUGH
2
3
REMOVE WIRE
MOUNTCURRENT
RECONNECT WIRE
SENSOR AS SHOWN
DISCHARGE SENSOR
WIRES
BOX & CONNECT
ACCORDING TO
GY
GY
Y
Y
T
O
WIRE DIAGRAM
O
PK
ROUTE WIRES
INTO LOW VOLTAGE
APPLY (2) BUSHINGS
FIGURE 3
FIGURE 2
MIS-1141
REMOVE SCREW
INSTALL DISCHARGE
SENSOR ASSEMBLY
AND INSTALL SCREWS
ROUTE WIRES TO
CONTROL PANEL
See Figure 4
on Page 4
MIS-3772
See Figure 4
on Page 4

Manual 7960-849
Page 4 of 4
LEFT HAND UNITRIGHT HAND UNIT
BOARD
INSTALL TERMINAL
VOLTAGE BOX AND
CAREFULLY PUSH
WIRES INTO LOW
ATTACH TERMINAL
BOARD LABEL TO
TERMINAL BOARD
BOARD
INSTALL TERMINAL
VOLTAGE BOX AND
CAREFULLY PUSH
WIRES INTO LOW
ATTACH TERMINAL
BOARD LABEL TO
TERMINAL BOARD
MIS-3774
16. Attach terminal board label to terminal board.
17. Attach “CMA-40” label and wiring diagram to the
inner control panel cover above the unit wiring
diagrams.
18. Make low voltage connections from the DDC
controller to the terminal board.
19. Install the blower access cover, control panel
covers and heater access panel.
20. Apply power to unit
21. Turn the unit blower on.
22. Restrict the filter of the unit by 75%.
23. Adjust the filter switch until it trips.
24. Remove restriction and reset filter switch.
25. Install the service panel.
9
10
11
12
13
14
15
16
COMPRESSOR CURRENT SENSOR
AIRFLOW SWITCH
TO THE LOW VOLTAGE TERMINAL BLOCK
+
NOTE: USE CLASS ONE WIRING FOR CONNECTION
MAX
COM .15A
30 VAC
@24 VAC
125 VA
@24 VAC
Figure 5
PK
T
Y
Y
O
O
GY
GY
DISCHARGE AIR SENSOR
FILTER SWITCH
TB6
24 VA
MIS-3717
LEGEND
GY GRAY
O ORANGE
YYELLOW
T TAN
PK PINK
LEGEND
GY GRAY
O ORANGE
YYELLOW
T TAN
PK PINK
FIGURE 4
10K ohm
@ 77˚F
FIGURE 5