Bard DC3002, Dc3003 User Manual

INSTALLATION INSTRUCTIONS

& REPLACEMENT PARTS LIST

DC3002 and DC3003 SOLID STATE

LEAD/LAG CONTROLLER

with DC FAN CONTROL

Bard Manufacturing Company, Inc.
Bryan, Ohio 43506

Since 1914...Moving ahead, just as planned.

Manual No.: 2100-484E
Supersedes: 2100-484D
File: Vol. III Tab 19
Date: 08-29-11

Manual 2100-484E
Page 1 of 22

CONTENTS

Getting Other Information and Publications 3
DC3000 General Information

Shipping Damage .................................................. 4

General .................................................................. 4

Theory of Operation............................................... 4

Controller Certifications ......................................... 4

Specifications/Features for Basic Controller

DC3000 Basic Controller ....................................... 5

Mounting the Controller

Installation Instructions .......................................... 5

T emperature Sensors

Remote Indoor Sensor........................................... 5

Remote Outdoor Sensor ........................................ 5

T emperature Sensor Logic

Using Multiple Sensors .......................................... 5

Controller Input/Output Specifications

Main Controller Board............................................ 6

Internal Alarm Board .............................................. 6

Low Voltage Field Wiring

Circuitry in the DC3000.......................................... 7

Controller Grounding

Earth ground .......................................................... 7

Security (Locking) Feature

Locking and Unlocking the DC3000 ...................... 9

Generator Run Feature

Standby Generator Disable Operation................... 9

Backup DC Power Connection

Input Connections Available .................................. 9

DC Fan Control

Free Cooling & Emergency Ventilation................ 10

Shelter Purge Control .......................................... 10

Controller Wiring

Refer to Connection Diagram ...................... 10 & 11

Alarm Wiring

Wiring Alarm Relays ............................................ 16

2nd Stage Cooling Alarm

Alarm Output is Available..................................... 16

Refrigerant Pressure Alarms

Connecting the Alarm Circuit ............................... 16

Emergency Ventilation Sequence
Using Economizers

Two Operating Sequences .................................. 16

Programming Instructions ................................... 19

Controller Power-Up

Time Delay on Power-Up....................................... 7

Fire Suppression Circuit

Disabling the DC3000............................................ 7

Staging Delay Periods

Stages 1 - 4............................................................ 7

Blower Operation

Various Blower Options ......................................... 7

Advance (Swap) Lead/Lag Unit Feature

Manual Switching of Units ..................................... 7

Accelerate Timer Feature

Testing the Timer Function..................................... 7

Humidity Control Option

Adding Optional Humidity Control.......................... 8

Sequence of Operation - Cooling (Air Conditioners)

No Economizer ...................................................... 8

With Economizers.................................................. 8

Sequence of Operation - Heating (Air Conditioners)

With Electric Heat .................................................. 9

Manual 2100-484E
Page 2 of 22

Figures

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7 Alarm Board Connections for Normally

(Label) DC3000 Series....................................... 20

Figure 8 Parts List Description ............................. 21

Tables

Table 1 Controller Connection Diagrams ............ 10

Table 2 Parts List ................................................ 22

DC3002 Controller Connections for 2 Air

Conditioners with Economizer ...................

DC3002 Controller Connections for 2 Air

Conditioners with No Economizer..............

DC3003 Controller Connections for 3 Air

Conditioners with 3 Economizers .............. 13

DC3003 Controller Connections for 3 Air
Conditioners with Economizers

(No Economizer A/C #3)......................... 14

DC3003 Controller Connections for 3 Air

Conditioners with No Economizers............ 15

Alarm Board Connections for Normally Closed

“NC” Open-On-Alarm Strategy................... 17

Open

“NO” Close-On-Alarm Strategy ..... 18

11

12

Getting Other Information and Publications

These publications can help you install the air
conditioner or heat pump. You can usually find these at
your local library or purchase them directly from the
publisher. Be sure to consult current edition of each
standard.

Standard for the Installation .............. ANSI/NFPA 90A

of Air Conditioning and
Ventilating Systems

Standard for Warm Air Heating ........ ANSI/NFPA 90B

and Air Conditioning Systems

FOR MORE INFORMATION, CONTACT
THESE PUBLISHERS:

ACCA Air Conditioning Contractors of America

1712 New Hampshire Avenue, NW
Washington, DC 20009
Telephone: [phone]
Fax: [phone]

ANSI American National Standards Institute

11 West Street, 13th Floor
New York, NY 10036
Telephone: [phone]
Fax: [phone]

ASHRAE American Society of Heating, Refrigerating,

and Air Conditioning Engineers, Inc.

1791 Tullie Circle, N.E.
Atlanta, GA 30329-2305
Telephone: [phone]
Fax: [phone]

BARD Bard Manufacturing Company, Inc.

1914 Randolph Drive
Bryan, OH 43506
Telephone: [phone]
Fax: [phone]

Manual 2100-484E
Page 3 of 22

** IMPORTANT **

The equipment covered in this manual is to be installed by
trained, experienced service and installation technicians.
Please read entire manual before proceeding.

SHIPPING DAMAGE

Upon receipt of equipment, the carton should be checked
for external signs of shipping damage. If damage is
found, the receiving party must contact the last carrier
immediately, preferably in writing, requesting inspection
by the carrier’s agent.

GENERAL

NOTE: DC3000 is used throughout this Manual as a
general reference to the controller system. There are
two controller models, DC3002 for 2 HVAC units and
DC3003 for 3 HVAC units, and these model numbers
are referenced when specific features or characteristics
apply only to either the DC3002 or the DC3003.
Occasional reference is made to alarm board AB3002 or
AB3003. AB3002 is the internal alarm board for the
DC3002 controller, and AB3003 is the internal alarm
board for the DC3003 controller.

These instructions explain the operation, installation and
troubleshooting of the DC3000 controller.

All internal wiring is complete. Only attach low voltage
field wiring to designated terminal strips.

THEORY OF OPERATION

The DC3002 controller is used to control two wall
mount air conditioners from one control system. It
provides total redundancy for the structure and equal
wear on both units. It can be used with units with or
without economizers and it is recommended that both
units be equipped alike.

The DC3003 controller is designed to control 3 air
conditioners, and can be used for 2 if it is anticipated the
third unit may be installed later.

NOTE: If this is done, see Note 1 on Alarm Board
Connections (Figure 6 or 7) to prevent nuisance Power
Loss Alarm indication for absent HVAC #3

When DC3003 is used for controlling three HVAC
units, only units 1 or 2 operate in lead/lag sequence.
HVAC #3 is always last to operate and functions only in
the number 3 position. All three units are available to
operate on-demand as required.

Alarm capability is standard on both models.

CONTROLLER CERTIFICATIONS

The DC3000 main controller board, optional alarm
boards, and remote sensors have undergone extensive
testing for immunity and emissions. This system is
FCC-compliant, in accordance with CE requirements,
and meets the following standards:

EN50082-2 Standard for Immunity
EN55011 Standard for Emissions

The DC3000 is for use with units with or without
economizers, and has a dehumidification control feature
if an optional humidity controller is connected.

Each unit should be sized to handle the total load of the
structure if 100% redundancy is required.

It is recommended that a five (5) minute compressor
time delay relay be installed in each unit.

The DC3000 controllers are suitable for both 50 and 60
HZ operation, and are fully configurable such that they
can be used in virtually any installation. See Controller
Programmable Features and Default Settings.

Manual 2100-484E
Page 4 of 22

SPECIFICATIONS/FEATURES FOR
BASIC CONTROLLER

DC3000 Basic Controller

•Input power: 18 to 32VAC, 60/50Hz, power is supplied
from A/C #1 and/or A/C #2

•Isolation circuitry: no line or low voltage phasing
required

•Backup power: connection for -24VDC or -48VDC
(-20 to -56V) maintains microprocessor operation, front
panel indication, and alarm relay operation during
commercial power outages.

•Digital display: 4-character LCD

•Temperature display: F or C

•HVAC outputs: Form A (NO) relays (1A @ 24VAC)

•Cooling control stages: 2 for each A/C unit

•Heating Control stages: 1 for each A/C unit

•Dehumidification circuit: requires optional humidity
controller as input signal.

•Operating temperature range: 0 to 120F (-18 to 49C)

•Storage temperature range: -20 to 140F (-29 to 60C)

•Temperature accuracy: +/- 1F from 60-85F (16-30C)
+/- 1% outside 60-85F

•Lead/lag changeover time: 0 to 30 days

•Timing accuracy: +/- 1%

•Inter-stage time delay: 10 seconds between stages

•Inter-stage differential: 2F (1C) for all modes

•On-Off differential: 2F (1C) is standard, 4F (3C) when

“excessive cycling” mode is enabled.

•Cooling set point range: 65 to 90F (18 to 32C)

•Comfort setting-Cooling 72F (22C), Heating 68F(20C),

for 1 hour.

•Dead band (difference between cooling and heating set

points): 2F to 20F (1C to 10C)

•Fire/smoke interface: standard NC circuit jumper, remove

for connection to building system control, shuts down both
A/C units immediately.

•Memory: EEPROM for set point and changeable

parameters (maintains settings on power loss).

•Temperature sensors: 1 local is standard, will accept up to

2 optional 25-foot remote sensors, Bard part number
8612-023. One can be used for remote indoor sensor and
one is dedicated for outdoor sensor for DC Fan free
cooling operation, if desired.

•Controller Enclosure: 20-gauge pre-painted steel, 9.25"W

x 13.50"H x 3.00"D, hinged cover, thirteen (13) .875"
diameter electrical knockouts.

•LEDs for basic controller: Lead unit, Cooling stages 1

through 4, Heating Stages 1 through 4, Dehumidification
operation. DC3003 has cooling stage and alarm LED’s
displayed internally for HVAC #3.

•Six (6) Push-button controls: On/Off switch-Change lead

unit-Increase and Decrease set points-Program/Save­Comfort.

MOUNTING THE CONTROLLER

Included in the controller carton is the controller and
installation instructions.

The controller should be installed on a vertical wall
approximately four (4) feet above the floor - away
from drafts and outside doors or windows. Four (4)
mounting holes are provided for mounting to the wall,
and 7/8" holes for conduit connections are provided in
both the base, sides and top of the controller.

TEMPERATURE SENSORS

The standard (local) temperature sensor has 12" leads
and comes installed from the factory.

The controller is designed to accept 1 additional
remote indoor sensor, and connects to “Rem 1”. The
Bard part number for the optional sensor with 25-foot
leads is 8612-023. This remote indoor sensor can be
installed as required in the structure to address hot
spots, barriers to airflow, etc. It can also be used as
the local sensor

Outdoor sensor, same 8612-023 with 25-foot leads, is
required for non-economizer installations when DC
fan is to be used for free cooling. This sensor
connects to the “Out” terminals.

It is recommended that the sensor lead wires be
installed in conduit for protective purposes.

The highest reading of any connected indoor sensor
will be used for high temperature alarm and the lowest
reading sensor will be used for low temperature alarm.

NOTE: All sensors are polarity sensitive. The

copper lead must connect to terminal CU,
and the silver lead to AG.

Sensors are solid state, not RTD.
Use only sensors supplied by Bard.

TEMPERATURE SENSOR LOGIC

The standard local (Loc) sensor monitors the
temperature at the controller location. If this is the
only sensor connected, it will control the temperature
read-out, the space (building) temperature, and also be
used for Low and High Temperature alarm functions.

If one REMOTE sensor is installed and connected
(Rem 1), the temperature read-out will display and the
building will be controlled to an average of connected
sensors. If there is more than 10F difference from the
highest to the lowest connected sensor, the actual
control will be governed by the hottest sensor for
cooling and the coldest sensor for heating.

If two indoor temperature sensors are used, the
average of the two sensors becomes the controller
cooling and testing set point.

Manual 2100-484E
Page 5 of 22

CONTROLLER INPUT/OUTPUT SPECIFICATIONS

DC3002/3003 CONTROLLER CONNECTIONS

Located on Main Controller Board

Unit #1 C – 24VAC common

R – 24VAC hot
G – fan (Form A, NO)

st

-stage cool (Form A, NO)

Y1 – 1
Y2 – 2nd-stage cool (Form A, NO)
W – heat (Form A, NO)

Unit #2 C – 24VAC common

R – 24VAC hot
G – fan (Form A, NO)
Y1 – 1st-stage cool (Form A, NO)

nd

Y2 – 2
W – heat (Form A, NO)

Unit #3 C – 24VAC common
(DC3003 only R – 24VAC hot
and located on G – fan (Form A, NO)
Internal Alarm Y1 – 1st-stage cool (Form A, NO)
Board) Y2 – 2nd-stage cool (Form A, NO)

W – heat (Form A, NO)

F1-F2 Fire/smoke interface

Shipped with jumper installed (a)

48Vdc Back-up power input

-24Vdc or –48Vdc

-20V to –56V range

Local Main sensor, 12-inch leads

CU – copper, AG – silver
Polarity sensitive

Rem 1 Optional remote indoor sensor

CU – copper, AG – silver
Polarity sensitive

Out Optional outdoor sensor (b)

CU – copper, AG – silver
Polarity sensitive

Gen Generator interface G1-G2

Shipped with jumper installed (a)

H1-H2 Humidity controller input

Requires optional controller
Field installed

(a) These connections require either jumper or Normally

Closed (NC) relay contact at the Fire/Smoke and Generator
interface for Controller to function.

(b) Required connection if field installed DC Fan is to be used

for free cooling and no economizers are installed in HVAC
units.

Note: All alarm relays are dry contacts rated 1A @

24VAC, 120VAC or 150VDC.

-stage cool (Form A, NO)

NOTE:

Sensors are

solid state,

not RTD.

Use Bard

sensors only.

DC3002/3003 CONTROLLER CONNECTIONS

Located on Internal Alarm Board AB3002

DC3002 Inputs

Lockout 1 2,3 – input from HVAC #1
Lockout 2 2, 3 – input from HVAC #2
Y Unit 1 signals when comp. #1 is active
Y Unit 2 signals when comp. #2 is active

DC3002 Alarm Outputs

Smoke/Fire Form C (SPDT)
Lockout 1 Form C (SPDT)

Refrigerant alarm HVAC #1

Lockout 2 Form C (SPDT)

Refrigerant alarm HVAC #2

Power Loss 1 Form C (SPDT)

Power loss HVAC #1

Power Loss 2 Form C (SPDT)

Power loss HVAC #2

Low Temp Form C (SPDT)

Low temperature alarm

High Temp 1 Form C (SPDT)

High temperature alarm #1

High Temp 2 Form C (SPDT)

High temperature alarm #2

Controller Form C (SPDT)

Controller failure alarm

DC3002 Control Outputs

Econ 1 E, F - Form A (NO)

See note (c )

Econ 2 E, F - Form A (NO)

See note (c )

DC Fan Form C (SPDT)

Pilot relay for DC Fan control

2nd Stage Form C (SPDT)

2nd-stage cooling alarm

(c ) Make these connections to terminals E & F in HVAC 1

and 2 respectively if desired to have economizers open for
emergency ventilation at High Temp Alarm #2 setpoint
condition.

DC3003 Inputs
Everything from DC3002 plus:

Lockout 3 2,3 – input from HVAC #3

DC3003 Alarm Outputs (on AB3003 Internal Alarm Board)
Everything from DC3002 plus:

Lockout 3 Form C (SPDT)

Refrigerant alarm HVAC # 3

Power Loss 3 Form C (SPDT)

Power loss HVAC #3

DC3003 Control Outputs

Econ 3 E, F - Form A (NO)

See note (c )

Alarm relays can be wired for NO (close on alarm) or NC (open on alarm) strategy. Alarm relays can be used individually if
there are enough available building alarm points, or can be arranged into smaller groups or even a single group so that all
alarm capabilities can be utilized. When multiple alarms are grouped together and issued as a single alarm there will be no
off-site indication of which specific problem may have occurred, only that one of the alarms in the group has been triggered.
The individual alarm problem will be displayed on the LED display on face of the controller.

Manual 2100-484E
Page 6 of 22

LOW VOLTAGE FIELD WIRING

The DC3000 is powered from the air conditioners that it
is controlling, 24VAC (18-32V) low voltage only.

Circuitry in the DC3000 isolates the power supplies of
all connected air conditioners so that no back feeds or
phasing problems can occur. Additionally, if any air
conditioner loses power, the DC3000 and the other air
conditioner are unaffected and will continue to operate
normally.

Connect the low voltage field wiring from each unit per
the low voltage field wiring diagrams in Section on
“Controller Wiring”.

CONTROLLER GROUNDING

A reliable earth ground must be connected in addition to
any grounding from conduit.

CONTROLLER POWER-UP

Whenever power is first applied to the controller, there
is a twenty (20) second time-delay prior to any function
(other than display) becoming active. This time-delay is
in effect if the controller On/Off button is used when
24VAC from air conditioners is present, and also if
controller is in “ON” position and 24VAC from all
connected air conditioners is removed and then restored.

FIRE SUPPRESSION CIRCUIT

To disable the DC3000 and shut down both air
conditioners, terminals F1 and F2 may be used. The F1
and F2 terminals must be jumpered together for normal
operation. A normally closed (nc) set of dry contacts
may be connected across the terminals and the factory
jumper removed for use with a field-installed fire
suppression system. The contacts must open if a fire is
detected. See appropriate connection diagram - Figures
1, 2 or 3 for this connection. Contacts should be rated
for pilot duty operation at 2 amp 24VAC minimum.
Shielded wire (22-gauge minimum) must be used, and
the shield must be grounded to the controller enclosure.

IMPORTANT NOTE: Some Bard models employ an
electronic blower control that has a 60-second blower
off-delay. In order to have immediate shutdown of the
blower motor, in addition to disabling the run function
of the air conditioners will require a simple wiring
modification at the blower control located in the
electrical control panel of the air conditioners being
controlled by the lead/lag controller. To eliminate the
60-second blower off-delay, disconnect and isolate the
wire that is factory-connected to the “R” terminal on the
electronic blower control, and then connect a jumper
from the “G” terminal on the blower control to the “R”
terminal on the blower control. The electronic blower
control will now function as an on-off relay with no off­delay, and the blower motor will stop running
immediately when the F1-F2 fire suppression circuit is
activated (opened).

STAGING DELAY PERIODS

The following delays are built in for both cooling and
heating:

Stage 1 –

Stage 2 –

Stage 3 –

Stage 4 –

Note: For cooling Stages 1 and 2, the stage LED will

blink for 10 seconds while the cooling output is delayed
after that stage is called for. There is also a delay after
the stage is satisfied, and after the LED stops blinking,
the stage will turn off. There is a minimum 10-second
delay between stages 2 & 3, and 3 & 4, but no delayed
output when stage is turned on or off, and LED for those
stages will not blink.

0 seconds for blower (if not already on as
continuous)
10 seconds for cooling or heating output

10 seconds after Stage 1 for blower

10 additional seconds for cooling or heating
output

10 seconds after Stage 2

10 seconds after Stage 3

BLOWER OPERATION

The controller can be configured to have main HVAC
blowers cycle on and off on demand; have all blowers
run continuously (for DC3003, the blower is not “On”
continuously for HVAC #3, but runs on demand only
condition); or have the lead unit blower run continuously
with the lag unit blower cycling on demand. Lead unit
blower operating continuously is the default setting.
There is also an option to have all blowers cycle on if one
remote sensor is connected, and a temperature difference
of more than 5F between any two sensors is observed.
This helps to redistribute the heat load within the structure
and should reduce compressor operating time.

When any of the stages are satisfied, the stage LED will
blink for ten (10) seconds before the stage is actually
turned off.

ADVANCE (SWAP) LEAD/LAG UNIT
FEATURE

Pressing the Advance button for one (1) second will cause
the lead and lag units to change positions. This may be
useful during service and maintenance procedures.

Note: DC3003 always operates HVAC #3 in last position:
only HVAC #1 and #2 operate in lead/lag sequence.

ACCELERATE TIMER FEATURE

Pressing the UP arrow button for five (5) seconds will
activate an accelerate (speed-up) mode, causing the
normal changeover time increments of days to be
reduced to seconds. Example: 7 days becomes 7
seconds. When “ACC” displays, release button.
Whichever LED is on, indicating lead unit will blink
over for each second until the controller switches. This
is a check for the timer functionality.

Manual 2100-484E
Page 7 of 22