154
JOHNSON CONTROLS
5276178-JIM-C-0118
Sequence of Operation
•
The
“UNDERFLOOR SLAB TEMP”
rises
to or above the
“MX SUPPLY AIR TEMP
SETPOINT”.
•
Or 20 minutes have elapsed.
Unoccupied Standby
1.
The Unit Control checks the
“UNDERFLOOR
SLAB TEMP”
immediately after transitioning from
Occupied to Unoccupied Standby mode.
2. If the
“UNDERFLOOR SLAB TEMP”
is less than
the
“RETURN AIR TEMP”
minus 2.0°F, the
“UN-
DER FLR TEMP OVRD”
shall be set to Active.
3. The
“UNDERFLOOR TEMP CONTROL SP”
is
set to the present instantaneous
“RETURN AIR
TEMP”
plus 10.0°F.
4. The Unit Control then generates a call for one stage
of heat for staged heat operation or controls the
“SUPPLY AIR TEMPERATURE”
to the
“UNDER-
FLOOR TEMP CONTROL SP”
for modulating
heat.
5. Heating operation will continue until:
a) The
“UNDERFLOOR SLAB TEMP”
rises
to or above the
“RETURN AIR TEMP”
plus
1.0°F.
b) Or 20 minutes has elapsed.
Dew Point Reset Sequence of Operation
The Unit Control uses the
“SUPPLY AIR TEMP”
and
the
“UNDERFLOOR AIR HUMIDITY”
to calculate the
“UNDERFLOOR SLAB DEW POINT”.
If the
“UNDERFLOOR SLAB DEW POINT”
is greater
than or equal to the
“UNDERFLOOR SLAB TEMP”
minus 2.0°F for 120 seconds, the Unit Control will
switch to the
“EVAP LEAVING AIR TEMP LOW”
set
point.
EXHAUST FAN OPERATION
On/Off Control Based On Damper Position
Required Programmed Values
“POWER EXHAUST TYPE”
must be set to
“ON-OFF
DAMPER CONTROL”
through the OPTION key,
EXHAUST subsection of the User Interface.
“ECONO OUPUT FOR FAN START”
must be set using
the SETPOINTS key, EXHAUST subsection of the
User Interface.
“ECONO OUPUT FOR FAN STOP”
must be set using
the SETPOINTS key, EXHAUST subsection of the
User Interface.
Operation
This option is only available on Constant Volume
units. The fixed speed motor is turned ON and OFF
based on the position of the outside air damper. The
Exhaust Motor is turned ON when the damper position
is more than or equal to the
“ECONO OUTPUT FOR
FAN START”
setting and turns OFF when the damper
position is less than or equal to the
“ECONO OUTPUT
FOR FAN STOP”
.
On/Off Control Based On Building Pressure
Required Programmed Values
“POWER EXHAUST TYPE”
must be set to
“ON-
OFF PRESS CONTROL”
through the OPTION key,
EXHAUST subsection of the User Interface.
“BUILDING PRESSURE ACTIVE SETPOINT”
must be
set using the SETPOINTS key, EXHAUST subsection
of the User Interface.
“BLDG PRESSURE CNTRL OFFSET”
must be set
using the SETPOINTS key, EXHAUST subsection of
the User Interface.
Operation
This option is available on all units. The fixed speed
exhaust motor is turned ON and OFF based on the
building pressure. When the Building Static Pressure
input is equal to or greater than the
“BUILDING
PRESSURE SETPOINT”
plus the
“BLDG PRESSURE
CNTL OFFSET”,
the exhaust fan will turn ON. When
the Building Static Pressure input is equal to or less
than the
“BUILDING PRESSURE SETPOINT”
minus
the
“BLDG PRESSURE CNTL OFFSET”
the exhaust
fan will turn OFF .
Modulating Damper with Fixed Speed
Exhaust
Required Programmed Values
“POWER EXHAUST TYPE”
must be set to
“MODULATE DAMPER - VFD”
through the OPTION
key, EXHAUST subsection of the User Interface.
“BUILDING PRESSURE SETPOINT”
must be set
using the SETPOINTS key, EXHAUST subsection of
the User Interface.
“EXHAUST OUTPUT FOR FAN START”
must be set
Summary of Contents for 40 25 TON
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