Greenheck Microprocessor Controller v3.0 (469690) - Manual (Page 8)

8
Supply Reset Limits
Supply Min:055.0ºF
Supply Max:090.0ºF
T HIS SCREEN DISPLAYS THE MINIMUM AND MAXIMUM SUPPLY AIR TEMPERATURE .
This screen only appears if the room supply temp sensor is wired into terminals B4
and BC4 on the controller.
The supply air temp will integrate SLOWLY down (Pl loop) towards this minimum set
point to maintain room temperature. The supply air temp will integrate SLOWLY up (PI
loop) towards this maximum set point to maintain room temperature.
Cold coil set point
Normal Mode:55.0ºF
Dehumidify:50.0ºF
Active set pt:55.0ºF
T HIS SCREEN DISPLAYS THE TEMPERATURE SET POINTS FOR THE COOLING COILS .
This screen only appears if a Cooling option was provided with the unit.
The Normal Mode set point is the after coil temperature the unit will maintain under
standard operation. If a Humidistat was provided with the unit, the Dehumidify set
point is the temperature the cooling coil will discharge on a call for dehumidification
from a humidistat.
The Active set pt is the temperature that the unit is currently trying to maintain off the coil.
Unoccupied room set
point
Heating:65.0ºF
Cooling:85.0ºF
T HIS SCREEN DISPLAYS THE ROOM SET POINTS WHICH DICTATE THE UNIT HEATING
AND COOLING OPERATION DURING UNOCCUPIED MODE .
This screen only appears if the “Cycle on Room” unoccupied mode was chosen
for the unit. A room sensor temp. must be wired into terminals B4 and BC4 on the
controller, and the unit must have a night setback damper.
In Unoccupied Mode when the temperature falls below the room Heating set point
(hysteresis = 5ºF), the supply fan and unit heating will turn on. Unit will discharge the
Supply Max temperature per the ‘Supply Reset Limits’ screen above until the room set
point is satisfied. Unit will then shut down. In Unoccupied Mode when the temperature
rises above the Cooling set point (hysteresis = 5ºF), the supply fan and unit cooling will
turn on. Unit will discharge the Supply Min temperature per the ‘Supply Reset Limits’
screen above until the room temperature set point is satisfied. Unit will then shut down.
Unit will energize
to maintain unocc
room set points.
Differential:5.0ºF
T HIS SCREEN DISPLAYS THE D IFFERENTIAL SET POINT FOR THE HEATING AND
COOLING MODES .
This screen only appears if the 7th character in the DDC Code is set to 1, meaning
the “Cycle on Room” unoccupied mode was chosen. Operation in “Cycle on Room”
unoccupied mode requires the room sensor be wired into terminals B4 and BC4 , and
a night setback damper in the unit.
This differential acts as a hysteresis to keep the heating and cooling from cycling too
often. For example, on a call for heating (room temp. set point - differential, 65.0ºF-
5.0ºF=60.0ºF) supply fan cycles on. Unit cycles off when the room temperature reaches
the Unoccupied room set point (65.0ºF, adjustable). For cooling, the differential is
added to the Unoccupied room set point (85.0ºF+5.0ºF=90.0ºF) to cycle supply fan
on. Unit cycles off when the room temperature reaches Unoccupied room set point
(85.0ºF).
SET POINTS MENU - continued
Room Set Point
Local set pt:72.0ºF
T HIS SCREEN DISPLAYS THE SPACE TEMPERATURE SET POINT .
This screen only appears if the room supply temp sensor is wired into terminals B4
and BC4 on the controller.
The unit will reset the unit discharge temperature up and down to maintain the local
set point. If a BMS is interfaced with the controller, the user has the capability to
dictate the desired Room set point through the BMS. The screen will show a BMS
set point and an Active set point. The Active set point is the room temperature the
controller is currently trying to maintain.
Heater Lockout
Lockout heater when
outside air >:70.0ºF
Hysteresis=02.0ºF
T
HIS CONTROLLER WILL LOCK THE HEATING SECTION OFF WHEN THE OUTDOOR AIR
TEMPERATURE IS ABOVE THE SET POINT ( FACTORY DEFAULT = 70ºF).
This screen only appears if a Heating option was provided with the unit.
A Hysteresis of 2ºF helps to avoid short cycling of the heater. The hysteresis is similar
to a deadband above and below the Lockout heater set point.
(Example: If Lockout = 70ºF, heating is locked out for outside air conditions above 72ºF
and enabled below 68ºF).