126
JOHNSON CONTROLS
5276178-JIM-C-0118
Sequence of Operation
SECTION 5 – SEQUENCE OF OPERATION
UNIT TYPE
The Unit Controller is capable of being programmed
for three different
“UNIT TYPE”
which establish the
mode of operation. The
“UNIT TYPE”
is set through
the OPTIONS key, UNIT DATA subsection of the User
Interface. The three options are:
•
“CONSTANT VOLUME”
•
“VARIABLE AIR VOLUM”
•
“FLEXSYS”
CURRENT OPER MODE
The
“CURRENT OPER MODE”
, occupied or
unoccupied, is a derived value and can be established
in three ways:
•
Digital Input “
OCCUPANCY STATE”
ON /OFF
input (“ON” occupied / “OFF” unoccupied).
The Digital input is made through a connection
between “24V” and
“OCC”
on the unit field low
voltage terminal block.
•
Serial Input
“OCCUPANCY COMMAND”
usu-
ally originates from a BAS system.
•
Internal Time Clock
“OCCUPANCY SCHED-
ULE”
the internal clock can be turned ON and
OFF through the SCHEDULE key of the User
Interface. The occupied / unoccupied schedule
can be programmed through the SCHEDULE
key of the User Interface.
Within the
“CURRENT OPER MODE”
are twenty sub-
modes of operation:
•
“OCCUPIED COOLING”
•
“OCC COOLING LOW”
•
“OCC COOLING HIGH”
•
“OCC COOLING W/ BYP”
•
“OCC COOLING W/O BYP”
•
“OCCUPIED HEATING”
•
“OCC HEATING LOW”
•
“OCC HEATING HIGH”
•
“OCCUPIED STANDBY”
•
“UNOCCUPIED COOLING”
•
“UNOC COOLING LOW”
•
“UNOC COOLING HIGH”
•
“UNOCCUPIED HEATING”
•
“UNOC HEATING LOW”
•
“UNOC HEATING HIGH”
•
“UNOCCUPIED STANDBY”
•
“COMFORT VENT COOLING”
•
“COMFORT VENT HEATING”
•
‘‘MORNING WARM UP”
•
‘‘UNDER FLOOR TEMP OVERRIDE”
The
“CURRENT OPER MODE”
can be viewed at the
STATUS screen.
The operation of the unit in each of the above modes of
operation will be defined later in this manual.
The Unit Controller monitors the switching from the
standby mode to an active cooling or heating mode. The
unit must be in the standby mode for 3 minutes before
the control will allow it to switch to an active heating
or cooling mode.
The Unit Controller also monitors the switching between
the active cooling and heating modes. The unit must
remain in one of the active heating or cooling modes for
30 seconds before it can be turned off or switched.
Constant Volume Mode
A
“CONSTANT VOLUME”
unit will be controlled by
one of three
“CONTROL METHODS”
:
•
“STAGED”
(Thermostat)
•
“WIRED ZONE TEMP”
(Hardwired)
•
“COMM ZONE TEMP”
(Communicated)
The
“CONTROL METHOD”
is entered into the Unit
Controller through the OPTION key, UNIT DATA
subsection of the User Interface.
Summary of Contents for 40 25 TON
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