Microprocessor Controller for DOAS
15
c
ooling
r
amp
1
This screen displays the active set point, supply discharge temperature, cooling
enable/disable, cooling ramp being sent from the controller, and the overall
capacity being demanded.
c
ompressor
r
equesT
The compressor request screen will be active if the unit is equipped with DX
cooling. This screen displays overall status of individual compressor operation
being sent from the unit controller. Example: Circuit A compressor enable (On)
with modulating value of 26%.
d
eFrosT
r
amp
o
uTpuT
This screen only appears if the unit has an energy recovery wheel and a frost
control method was provided on the unit.
Upon sensing a high differential pressure across the energy wheel, the unit will
go into defrost if the outside air temperature is below the defrost temperature set
point.
Unit Status Overview
h
eaT
p
ump
h
eaTing
r
amp
The Heat Pump Heating Ramp status screen is active when the unit is configured
as a heat pump. The screen displays the active set point, supply temperature,
status of the heat pump heating control ramp, the current ramp percentage, and
the current capacity of the operating compressors.
e
x
v s
TaTus
The ExV Status screen is active when the unit is equipped with an inverter
scroll compressor and electronic expansion valve (ExV). The screen displays
information from the EVD (electronic valve driver) including the number of steps
(stp) of the valve, the open percentage of the valve, the EVD control status,
the suction superheat, the suction temperature, the suction pressure, and the
saturated suction temperature. The second status screen also displays the
capacity of the circuit the valve is installed on and the discharge refrigerant
temperature for that circuit.
i
nverTer
c
ompressor
s
TaTus
The inverter compressor screen is active when an inverter scroll compressor is
installed in the unit. This screen displays information about the operation of the
inverter scroll starting with the requested capacity of the compressor compared
to its actual operating capacity. The requested capacity and the actual could
be different at startup and depending on where it is in the operating envelope.
The status of the compressor, current envelope zone and current refrigerant
temperatures and pressures are also displayed.
c
ondenser
F
an
s
TaTus
The pressure control status screen is active when a unit is equipped with
active head pressure control, this is currently available only with inverter scroll
compressors. This screen provides information regarding the outside fan ramp
status, circuits affected by the ramp, the status of the fans, and the set point,
offset and current saturated temperature.
