Bard CRVS-3A User manual

Page 1 of 16
INSTALLATION INSTRUCTIONS
Bard Manufacturing Company, Inc.
Bryan, Ohio 43506
www.bardhvac.com
Manual: 2100-759
Supersedes: NEW
Date: 12-8-21
Commercial Room Ventilator
with Exhaust
For Use with Bard Heat Pump Models
T24H, T30H and T30S
Model: CRVS-3A

Manual 2100-759
Page 2 of 16
CONTENTS
General
General Information..............................................3
Unpacking...........................................................3
Description ..........................................................3
Models ................................................................3
CRV Features .......................................................3
Sequence of Operation.......................................... 3
Installation
Basic Installation ................................................. 4
CO2Control..........................................................7
Blade Adjustment for Desired Ventilation Air.........10
"V" Option CRV Sequence of Operation .................12
Figures
Figure 1 Removal of Exterior Panels..................... 4
Figure 2 Removal of Exhaust Cover Plate.............. 5
Figure 3 Install Ventilator ...................................6
Figure 4 8403-096 CO2Sensor Set Up................8
Figure 5 CRV Control Board Wiring ......................9
Figure 6 CRV Control Board ..............................11
Figure 7 CRV Control Board ..............................12
Figure 8 Call for Ventilation with or without
Compressor Operation..........................15
Figure 9 Call for Compressor or Fan Only
with Ventilation Off ............................. 16
Graphs
Graph 1 T30* High Speed Total and
Vent Airow ........................................ 14
Graph 2 T24H High & T30* Low Speed Total
and Vent Airow.................................. 14

Manual 2100-759
Page 3 of 16
General Information
The ventilator should only be installed by a trained
heating and air conditioning technician. These
instructions serve as a guide to the technician
installing the ventilator package. They are not
intended as a step-by-step procedure with which the
mechanically inclined owner can install the package.
The ventilator housing is shipped in one carton which
contains the electrical harness, miscellaneous hardware
and installation instructions.
Unpacking
Upon receipt of the equipment, be sure to compare the
model number found on the shipping label with the
accessory identication information on the ordering and
shipping document to verify that the correct accessory
has been shipped.
Inspect the carton housing of each ventilator as it is
received. Before signing the freight bill, verify that all
items have been received and that there is no visible
damage. Note any shortages or damage on all copies
of the freight bill. The receiving party must contact
the last carrier immediately, preferably in writing,
requesting inspection by the carrier’s agent. Concealed
damage not discovered until after loading must be
reported to the carrier within 15 days of its receipt.
Description
The CRVS-3A ventilator is designed to be used with
Bard heat pump models T24H, T30H and T30S. It is
an electromechanical vent system designed to provide
fresh air to meet indoor air quality standards.
Models
When installed in the above listed models, the CRV
provides built-in exhaust provisions. When the damper
blade opens to bring fresh air in, the damper also
opens an exhaust relief. The exhaust air will ow into
the condenser section of the unit. The condenser fan
will help draw exhaust air out.
CRV Features
• One piece construction – easy to install.
• Exhaust air damper – built in with positive closed
position. Provides exhaust air capability to prevent
pressurization of tight buildings.
• Actuator motor – 24 volt, power open, spring return
with built in torque limiting switch.
GENERAL
Electrical shock hazard.
Disconnect remote electrical power supply
or supplies before servicing.
Failure to do so could result in electric
shock or death.
!WARNING
Exposed moving parts.
Disconnect all electrical power before
servicing.
Failure to do so can result in severe injury
or amputation.
!WARNING
Sequence of Operation
On a call for blower operation, CRV will open to
pre-purge position as set by "PP" potentiometer
for the amount of time set by the PP jumper. The
CRV will then move to the position set by the "OCC"
potentiometer. If PP jumper is in 0 position, the CRV
will immediately open to the position set by the "OCC"
potentiometer.
NOTE:
These sequence descriptions do not apply if CO
2
controller is used. The CRV will control according
to observed CO
2
levels in the conditioned space.
Refer to information on page 8.
A call for 1st stage cooling or heating cycles the
compressor, and the dampers reposition to the Y1
potentiometer setpoint. A call for 2nd stage cooling or
heating energizes compressor solenoid and repositions
the damper blade to the Y2 potentiometer position. On
loss of blower operation, CRV closes fully.
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

Manual 2100-759
Page 4 of 16
Model For Use with
Following Units
CRVS-3A
T24H
T24H1D
T30H
T30H1D
T30S
T30S1D
INSTALLATION
Basic Installation
1. Unpack the ventilator assembly which includes the
integral ventilator with attached electrical harness
and miscellaneous hardware.
2. Remove and save the existing exterior blower
access and service access panels on the Bard wall
mount unit (see Figure 1).
Open and lock disconnect switch before
installing this accessory to prevent injury or
death due to electrical shock or contact with
moving parts. Turn thermostat to o.
!WARNING
FIGURE 1
Removal of Exterior Panels

Manual 2100-759
Page 5 of 16
3. Remove and save existing unit return air lter and
left side lter support bracket by removing two
(2) screws from front side of unit (see Figure 2).
Remove and save top four (4) screws from grille.
4. Remove and discard the exhaust cover plate.
FIGURE 2
Removal of Exhaust Cover Plate

Manual 2100-759
Page 6 of 16
5. Install ventilator into unit (see Figure 3).
IMPORTANT: Position front lip of ventilator on top
of front grille and condenser partition (see Figure 3
inset). This is important to ensure proper drainage
of any water entering damper assembly.
5. Open control panel to gain access to unit low
voltage terminal block.
6. Route electrical harness leads through the 7/8"
bushings in control panel into low voltage box (as
shown in Figure 3).
Note:
When installing CRV
position so hole infront
Plug the (4) Ø.125 holes
in the service door with
insert a self drilling screw.
WIRES
in condenser grille to
lip is centered over hole
CRV in unit
Right side of
Route the pink, purple,
grille and service door
MIS-2030 A
Lip of CRVisto be
canoe clips.
Service Door
with doors
removed
Front Grille
Front of unit
between the condenser
the upper grommet.
and black wires through
Place the provided ventilator slides
in the unit and position the vent package sides
on top of them. Use these to slide the vent into
the unit. Ventilator slides should be removed
after installation.
FIGURE 3
Install Ventilator

Manual 2100-759
Page 7 of 16
7. Make the following connections from the CRV wire
harness to the screw terminals on the low voltage
terminal strip:
• Brown/White wire to the "01" terminal
• Black/White wire to the "C" terminal
• Red/White wire to the "R" terminal
• Orange wire to the "G" terminal
• Yellow/White wire to the "Y" terminal
• Purple wire to the "Y1" terminal
8. Close control panel cover
9. Replace left lter support, lter and four (4)
screws in condenser grille.
10. Re-install the blower access panel at top of unit
and secure with sheet metal screws.
11. Ventilator Checkout
A. Resupply power to unit.
B. Move "PP" jumper on CRV control board (Bard
P/N 8201-167) to the 30-minute position.
C. Ventilator should open to the position
set by the "PP" potentiometer. Cycle the
potentiometer from full open to full closed.
Observe damper blade operation throughout
travel to assure free, unobstructed movement.
Return "PP" potentiometer to desired position
for pre-purge airow (refer to graphs 1 and 2
on pages xx-xx). Move the "PP" jumper to the 0
position. Ventilator should open to the position
set by the "OCC" potentiometer.
Energize Y; ventilator should open to the
position set by the "Y1" potentiometer.
Energize Y1; ventilator should open to the
position set by the "Y2" potentiometer.
D. De-energize evaporator blower. Damper blade
should close.
E. If pre-purge function is desired, move "PP"
jumper to the 30-, 60-, or 90-minute position
depending on desired pre-purge time.
F. This completes ventilator checkout.
12. Replace mist eliminator. Be sure it is installed with
the drain holes to the bottom.
13. Remove blank off plate or barometric fresh air
damper installed on service access door. Plug four
(4) mounting holes with the plastic plugs provided
with the ventilator.
14. Replace service access panel.
15. Ventilator is now ready for operation.
16. If retrotting an existing unit, thermostat
connection may change. See latest revision of
manual 2100-507, 2100-516 or 2100-554 for
proper thermostat connections to low voltage
terminal strip with this CRVS.
CO2Control
For CO2-based control, add a CO2sensor/controller
(Bard P/N 8403-096) to the wall and run additional
optional wires as shown in Figure 5 on page 9.
The CO2controller also must be re-congured from the
standard default settings as it comes out of the box.
See Figure 4 on page 8 for complete details.

Manual 2100-759
Page 8 of 16
FIGURE 4
8403-096 CO2Sensor Set Up
ON
OFFOFFOFF
ON
4 65
23
ON
1
PRESS UP AND DOWN
ARROWS TO ENTER
CONFIGURATION MODE
USE ARROWS TO SELECT
SETTING. PUSH MIDDLE
BUTTON TO CHANGE.
CONTROLLER WILL
SHOW SET.
IT HAS BEEN CONFIGURED.
DIP SWITCH TO "OFF" AFTER
CONTROLLER MOVE
NOTE: MENU
DIP SWITCH MUST
BE IN "ON" POSITION #5
TO CHANGE ANY
SETTINGS WITH
THE SIDE BUTTONS.
TO LOCK THE CO2
DIP SWITCHES MUST BE
POSITIONED AS SHOWN
FOR PROPER OPERATION MIS-4025 C
Settings Recommended Default
RON
(RELAY ON SET POINT) 725
ROF
(RELAY OFF SET POINT) 700
DSP
(DISPLAY
CONFIGURATION) C CT
UNI
(UNITS SELECTION) US US
COL
(CO2 LOW OUTPUT
RANGE) 700 0
COH
(CO2 HIGH OUTPUT
RANGE) 1500 2000
TOL
(TEMP. LOW OUTPUT
RANGE) Not Used
TOH
(TEMP. HIGH OUTPUT
RANGE) Not Used
BAR
(BAROMETRIC
PRESSURE)
See Instructions with
Controller For High
Altitude Installations
CAL
(CALIBRATION) Used for Field Calibration

Manual 2100-759
Page 9 of 16
FIGURE 5
CRV Control Board Wiring
3
1
2
5
4
6
UNIT LOW VOLTAGE
BROWN/WHITE
TERMINAL STRIP
OPTIONAL
YELLOW/WHITE
OPTIONAL
PURPLE
OPTIONAL WHEN
INDOOR FAN IS ON
MODULATING CO2 CONTROL
*A -
RED/WHITE
CONTROL
FDBK
24V
COM
KEY
ON/OFF CO2 CONTROL
*B -
*C
BE O1
4056-261 A
CY1Y
*D
W1
RG
*C - SINGLE-STAGE UNIT
*D - FIELD JUMPER FOR
CONSTANTVENTILATION
BLACK/WHITE
BROWN/WHITE
ORANGE
BROWN/WHITE
RELAY
BLACK/WHITE
56
30
0
CRV-CONTROL BOARD
60
-
Damper Motor
RED
BLACK BROWN
*A
CO2 Sensor
90
*A
OPTIONAL CO2 CONTROL
*B
55
+
REQUIRED FIELD WIRING FOR
CO2 VENTILATION OPERATION.
IN *B CONFIGURATION FOR MODULATING
PANEL UNLESS A CO2 SENSOR ISINSTALLED
GRAY WIREISDEAD-ENDED IN CONTROL
59
56
57
*UNUSED-
TAPE OFF*
WHITE
57
L
W2
GRAY
NC
NO
1
COM
49
MOVE THIS BROWN/WHITE WIRE
FROM COM TO NC IF JUMPERIS USED
BETWEEN01 AND G.

Manual 2100-759
Page 10 of 16
Blade Adjustment for Desired
Ventilator Air
The amount of ventilation air supplied by the
commercial room ventilator is dependent on four (4)
factors:
1. Return air duct static pressure drop.
2. Supply air duct static pressure drop.
3. Indoor blower motor speed.
4. Damper blade open position setting.
Refer to the graph below to determine the blade setting
necessary to achieve the ventilation air required for
each operating mode.
Factory default settings are:
TS TH
PP Potentiometer Closed Closed
OCC Potentiometer C C
Y1 Potentiometer C C
Y2 Potentiometer C C
Vent is factory set to supply between 100 and 150
CFM of fresh air in all modes of occupied operation.
For more accurate adjustment, use a owhood over
the intake opening to measure and adjust the airow
operation.
PP Potentiometer: Adjusts the airow during pre-purge
mode (if jumper is installed in positions 30-90).
OCC Potentiometer: Adjusts the airow during blower-
only operation, or during an occupied input from an
applicable thermostat.
Y1 Potentiometer: Adjusts the airow during 1st stage
cooling or heating operation.
Y2 Potentiometer: Adjusts the airow during 2nd stage
cooling or heating operation.
Energize blower-only mode and adjust OCC
potentiometer to desired airow.
Energize 1st stage cooling mode and adjust Y1
potentiometer to desired airow.
Energize 2nd stage cooling mode and adjust Y2
potentiometer to desired airow.
If pre-purge mode is desired, de-energize cooling
modes. Move PP jumper to the 30-, 60-, or 90-minute
position and adjust PP potentiometer to desired airow.
Minimum damper position when using CO2control
damper should be fully closed at 700 ppm or lower, if
not OCC potentiometer OCC can be adjusted counter-
clockwise (CCW) to close it. If it is fully closed at 700
ppm or lower, no adjustments required.

Manual 2100-759
Page 11 of 16
MIS-4047
60
30
90
0
STAGE ONE COOLING
POT "Y1" SETTING FOR
WHEN Y2 IS ENERGIZED
COOLING OR BLADE POSITION
Y1 WILL OVERRIDE OCC
POT "PP" PRE-PURGE
SET FOR PREOCCUPANCY
POT "OCC" OCCUPIED SETTING
TURN OFF FOR C02
FULL MODULATION
SETTING FOR 2ND STAGE
PRE-PURGE
TIMER
FIGURE 6
CRV Control Board

Manual 2100-759
Page 12 of 16
"V" Option CRV Sequence of Operation
The “V” Ventilation option includes a control board with
blade positioning potentiometers along with an input
for a 2-10V input signal (see Figure 7).
Adjustable potentiometers:
“PP” Potentiometer setting: This potentiometer can be
used to adjust the blade setting for outdoor air intake
during a pre-purge cycle. The pre-purge cycle time is
based on the setting of the pre-purge timer.
“OCC” Potentiometer setting: This potentiometer can
be used to adjust the blade setting for outdoor air
intake when the “01” terminal is energized on the low
voltage terminal strip indicating occupancy.
“Y1” Potentiometer setting: This potentiometer can be
used to adjust the blade setting for outdoor air intake
when the “Y” terminal is energized on the low voltage
terminal strip indicating 1st stage cooling or Balanced
Climate operation. When energized, it overrides the
“OCC” potentiometer setting.
“Y2” Potentiometer setting: This potentiometer can be
used to adjust the blade setting for outdoor air intake
when the “Y1” terminal is energized on the low voltage
terminal strip indicating 2nd stage cooling operation.
When energized, it overrides the “OCC” and “Y1”
potentiometer settings.
Pre-Purge Feature
Pre-purge is used to ventilate a specied CFM amount
before occupants enter the room or structure. The
control board has a built-in pre-purge timer that can be
set to 30-, 60- and 90-minute intervals by moving the
jumper noted in Figure 6 on page 11. This timer will
start when the jumper is installed and the "01" terminal
is energized on the low voltage terminal strip. Blade
adjustment can be made on the PP potentiometer.
Once the timer has timed out, the board will default
to the occupied setting and this blade position can
be adjusted on the OCC potentiometer. If the timer is
set to 0 (off—shipped position), the occupied setting
is instantaneous and the pre-purge setting (PP) is no
longer in the sequence.
Occupied Setting
Occupied is used to ventilate a specied CFM amount
when occupants enter the room or structure. The
control board will energize the occupied setting
after the pre-purge cycle, or if pre-purge is disabled
immediately when the "01" terminal is energized on the
low voltage strip. Blade adjustment can be made on the
OCC potentiometer.
Y1 Setting
Y1 is used to ventilate a specied CFM amount when
Y cooling is energized. The control board will energize
the Y1 setting when Y is energized on the low voltage
strip. Blade adjustment can be made on the Y1
90
60
30
0
FIGURE 7
CRV Control Board
potentiometer. This potentiometer setting overrides the
OCC occupied setting.
Y2 Setting
Y2 is used to ventilate a specied CFM amount when
Y1 cooling is energized. The control board will energize
the Y2 setting when Y1 is energized on the low voltage
strip. Blade adjustment can be made on the Y2
potentiometer. This potentiometer setting overrides the
OCC occupied and the Y1 setting.
2-10V Operation
A CO2sensor or other device sending a 2-10V signal
can be used to control the damper motor. Two control
methods are available to control the damper motor:
• Method 1: The control board will accept a
2-10VDC signal with a resistive load greater than
5000 ohms. Bard CO2sensor 8403-096 can be
used when the 2-10V output is connected to the
blade connector on the unlanded gray wire from
the CRV, located near the unit low voltage terminal
strip. The occupied OCC potentiometer setting
must be set to the off position for total modulation.
The OCC potentiometer can be used to maintain a
minimum blade position when "01" is energized.
• Method 2: The damper motor will accept a
2-10VDC signal with a resistive load less than
5000 ohms. This method involves bypassing the
control board and powering the motor directly from
the device providing the 2-10VDC modulating
signal. The gray wire connected to CO2VIN on the
control board must be spliced with the white wire

Manual 2100-759
Page 13 of 16
ran to the damper motor (OUT on control board).
The other end of the gray wire should be connected
to the CO2sensor as stated in Method 1.
During 2-10VDC operation with "01" energized and
pre-purge timed operation active, DC voltage signaling
occupancy from a source such as a CO2sensor will
increase ventilation amounts as needed.

Manual 2100-759
Page 14 of 16
GRAPH 2
T24H High Speed Total and Ventilation Airow/T30* Low Speed Total and Ventilation Airow
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
A
B
C
D
E
F
Airflow (cfm)
Vent Position
Total Air 0 ESP
Total Air .2 ESP
Total Air .4 ESP
Vent Air 0 ESP
Vent Air .2 ESP
Vent Air .4 ESP
0
100
200
300
400
500
600
700
800
900
0
A
B
C
D
E
F
Airflow (cfm)
Vent Position
Total Air 0 ESP
Total Air .2 ESP
Total Air .4 ESP
Vent Air 0 ESP
Vent Air .2 ESP
Vent Air .4 ESP
GRAPH 1
T30* High Speed Total and Ventilation Airow

Manual 2100-759
Page 15 of 16
FIGURE 8
Call for Ventilation
with or without Compressor Operation
MIS-347A
Supply Air
Evaporator
Coil
DAMPER BLADE EXHAUST AIR
Return Air
Condenser Air
Direction
Condenser
Coil
Outside Air

Manual 2100-759
Page 16 of 16
MIS-348A
Supply Air
Return Air
Evaporator
Coil
DAMPER BLADE
Condenser Air
Direction
Condenser
Coil
FIGURE 9
Call for Compressor or Fan Only
with Ventilation Off