Greenheck DOAS v8.1 Reference Manual page 20

20 Microprocessor Controller for DOAS
Menu
c l
ooling ockouT
This screen displays the cooling lockout temperature. Cooling will be disabled
when outside air is below the cooling lockout temperature (55ºF).
e l
conomizer ockouT
The screen displays the economizer lockout temperature when economizer is
enabled in the unit. Economizer is not available when the outside air temperature
is below the lockout temperature (40°F).
h l
eaTing ockouT
This screen displays the heating lockout temperature. Heating will be disabled
when outside air is above the lockout temperature (80ºF).
p l
reheaT ockouT
The preheat lockout screen appears when preheat is installed in the unit. Preheat
is not allowed when the outside air temperature is above the lockout temperature
(10°F). Further, the outside damper position must be greater than the OAD En Pos
setpoint (30%), on recirculating air units where preheat may be allowed.
w r
inTer amp
The winter ramp function prevents the supply temperature from dropping below
setpoint under the following conditions:
• Outside air temperature is below the winter ramp enable setpoint; and
• Heating capacity is at 100%
One of the following is used to perform the winter ramp function:
• Supply fan speed; or
• Outside air damper position
Note: If the unit is a heat pump, the supply fan is always used.
c h
ase eaT
The case heat function allows the use of the hot water valve modulation to
maintain the temperature of the case when the unit is off or in standby mode.
Case heat can be disabled with the service password in Ctrl Variables/Advanced/
Adv. Setpoints.
m s T-s
odbus pace TaT
The quantity of thermostats installed in the space that communicate the
temperature, humidity, and setpoint to the controller. The controller averages the
temperature and humidity readings when there is more than one installed. See
Appendix C for more information.
e m
conomizer ode
The economizer screen appears when economizer function is enabled.
The outside air damper will modulate between the min and max position to
maintain the supply temperature setpoint.
The user can select the economizer control method from the following options:
Outside Dry Bulb – Economizing is allowed when the outside dry bulb is less
than the economizer temperature setpoint (65°F).
Outside Enthalpy - Economizing is allowed when outside enthalpy is less than
the economizer enthalpy setpoint (23/btu/lb).