Bard MC4000 User Manual

Manual 2100-563C
Page

6 of 40

SPECIFICATIONS/FEATURES FOR
ALARM BOARDS

MC4000-A w/Optional Base Alarm Board
(Inputs/Outputs)

NOTE: If this alarm board was not originally factory
installed, it can be field-installed at anytime. Bard
part number is AB3000-A.

MC4000-B w/Enhanced Version Alarm Board
(Additional Outputs) plus MC4000-A Inputs/Outputs

NOTE: If this alarm board was not originally factory
installed, it can be field-installed at anytime. Bard
part number is AB3000-B.

Note: All alarm and output relays are dry contacts rated
1A @ 24 VAC.

BASIC MC4000 CONTROLLER
INPUT/OUTPUT SPECIFICATIONS

MC4000 CONTROLLER CONNECTIONS

Located on Main Controller Board

Unit #1

C – 24VAC common
R – 24VAC hot
G – fan (Form A, NO)
Y1 – 1

-stage cool (Form A, NO)

Y2 – 2

-stage cool (Form A, NO)

W – heat (Form A, NO)

Unit #2

C – 24VAC common
R – 24VAC hot
G – fan (Form A, NO)
Y1 – 1

-stage cool (Form A, NO)

Y2 – 2

-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

Rem 2

Optional remote indoor sensor
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.

Inputs
Lockout 1

2,3 – input from HVAC #1

Lockout 2

2, 3 – input from HVAC #2

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

Econ 1

E, F - Form A (NO)
See note (b)

Econ 2

E, F - Form A (NO)
See note (b)

Stage (c)

Form C (SPDT)
2

-stage cooling alarm

(b) 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.

alarm activates on cooling Stage 3 initiation.

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.

NOTE:

Sensors are

solid state,

not RTD.

Use Bard

sensors only.

Note: All alarm relay outputs have 10-second delay
before issuing to protect against nuisance alarm signals.