Manual 2100-614K
Page
15 of 61
automatically operate on compressor Stage 1 partial
capacity instead of the economizer.
2
nd
cooling setpoint is 4F (default setting, user
selectable 2-6F) warmer than Stage 1. On a call for
2
nd
stage cooling the lead unit Y2 cooling output turns
on. If the outdoor temperature and humidity conditions
are below the setpoint of the economizer control the
lead unit economizer will continue to operate, and the
compressor will operate on compressor Stage 1 partial
capacity. If the compressor is already operating on
Stage 1 partial capacity because outside free cooling
range the compressor will switch to compressor Stage 2
full capacity.
3
rd
cooling setpoint is 2F (default setting, user
selectable 2-3F) warmer than Stage 2. On a call for 3
rd
Stage cooling the blower of the lag unit will come on
immediately (if not already on – See Blower Operation),
and the Stage 3 LED will blink for 10-seconds before
going solid, at which time the lag unit Y1 cooling
output turns on. The lag unit economizer will operate
if the outdoor temperature and humidity conditions are
below the setpoint of the economizer control. If outdoor
conditions are not acceptable for free cooling the
compressor will automatically operate on compressor
Stage 1 partial capacity instead of the economizer.
4
th
cooling setpoint is 2F (default setting, user
selectable 2-3F) warmer than Stage 3. On a call for 4
th
Stage cooling the lag unit Y2 cooling output turns on
activating the compressor. If the outdoor temperature
and humidity conditions are below the setpoint of
the economizer control the lag unit economizer will
continue to operate, and the compressor will operate on
compressor Stage 2 full capacity. If the compressor is
already operating on Stage 1 partial capacity because
outside free cooling range the compressor will switch to
compressor Stage 2 full capacity.
NOTE A:
Economizers in ECONWM* or WECOP Series
are available with either “T” temperature only outdoor
sensor or “E” enthalpy (temperature and humidity)
outdoor sensor. The “T” versions will have a fixed (but
selectable) outdoor temperature decision whereas on
the “E” versions the outdoor temperature decision
will float based on outdoor humidity and the selected
Enthalpy curve in the economizer control module.
HEATING SEQUENCE OF OPERATION
NOTE:
All heating sequences for air conditioners with
electric heat or heat pumps will automatically operate
in Alternating Lead/Lag/Lead/Lag sequence even if
controller is set to Non-Alternating for cooling with or
without economizers.
1. Air Conditioners with Electric Heat
1
st
stage heating setpoint is the dead-band (db) below
the 1
st
stage cooling setpoint (the SP entered into the
program). The dead-band is adjustable from 2-40F, and
factory default is 17F.
2
nd
stage heating setpoint will operate at same inter-
stage differential as set for cooling mode.
2. Heat Pumps with Electric Heat
When the MC4002 controller is configured for heat pump
installations the 2
nd
-stage (Y2) outputs for both units 1
and 2 are redefined and used to control the reversing
valves, and which are energized in heating mode.
1
st
stage heating setpoint is the dead-band (db) below
the 1
st
stage cooling setpoint (the SP entered into the
program). The dead-band is adjustable from 2-40F, and
factory default is 17F.
1
st
-stage heating consists of lead unit blower coming
on (if not already on – See Blower Operation), and
reversing valve being energized. The Stage 1 heating
LED will blink for 10-seconds, at which time the
compressor turns on.
2
nd
heating setpoint is 4F (default setting, user
selectable 2-6F) cooler than Stage 1. On a call for 2
nd
Stage heating the blower of the lag unit is turned on (if
not already on – See Blower Operation), the reversing
valve is energized, and the Stage 2 LED will blink
for 10-seconds before going solid, at which time the
compressor will start.
3
rd
-stage heating will be the electric heater, if so
equipped, in the lead unit. Stage 3 heating LED comes
on solid with no blinking.
4
th
-stage heating will be the electric heater, if so
equipped, in the lag unit. Stage 4 heating LED comes
on solid with no blinking.
SPECIFICATIONS FOR OPTIONAL
REMOTE COMMUNICATION BOARD
CB5000 Series Communication Board
NOTE:
If the communication board (Bard CB5000
Series) was not originally factory installed, it can be
field installed at anytime. It allows remote access via
Ethernet, depending upon level of authority assigned,
to all functions of the controller system the same as if
one was in the building where the controller system is
physically installed.
Required input connections to the CB5000 Series
(these are all internal connections from either the alarm
board or main controller board):
1. Fire/smoke connection from MC4002 main
controller board.
2. Refrigerant lockout inputs.
3. If economizers are used, an additional 24V signal
wire is required from each air conditioner to the
controller system.
