occurs, gas is drawn into the scrolls and moved in
increasingly smaller pockets toward the center. At
this point the gas, now compressed to a high
pressure,
is discharged from a port in the center if the fixed
scroll. During each orbit, several pockets of gas are
compressed simultaneously, creating smooth, nearly
continuous compression.
1.4.5.1 Electronic Expansion Valve
The
E²
system controller manages the operation of
the electronic expansion valve (EEV) for each
refrigeration circuit. The controller manages the EEV
based on input signals from the suction pressure and
temperature sensors. It regulates the amount of
refrigerant entering the evaporator to maintain the
correct superheat temperature.
1.4.6 Coils
The evaporator coils are aluminum finned/copper
tube construction. The coils are leak tested prior to
installation by the factory. A condensate drain pan is
provided to collect water condensed by the coils.
The drain pan is emptied by gravity drain that directs
the water away from the cabinet. A condensate pump
may be provided as an option.
1.4.7 EC Fan(s)
The unit is equipped with high efficiency,
Electronically Commutated (EC) fan(s). EC Fans
utilize a brushless motor equipped with permanent
magnets and permanently lubricated ball bearing.
The Fan impellers are backward curved and
attached to the rotor casing. The fan is balanced and
aerodynamically optimized to minimize vibration.
The fan does not utilize drive belts. The fan
speed is variable via a 0 to 10 VDC signal from
the system controller. The fan motor is equipped
with integral
electronics and does not require the addition of
secondary electronics such as thermal protection,
inverters or filters. The fan will not produce AC
inverter whine.
EC fans feature an integrated monitoring function
to protect the motor and electronics against
damage from jamming, phase loss or overheating.
The
E²
controller monitors each fan via the modbus and if
any of the following failure conditions occur, the
motor automatically stops and an alarm is signaled:
a. Locked rotor
b. Low main supply voltage
c. Loss of a phase
d. Over-heating of electronics
e. Over-heating of motor
If a communication loss occurs, the fans will run
at their last received output command until a
new
CyberAiR DX Floor Mounted IOM Manual
command is received (Modbus comm is back
online). If a power cycle occurs, (dual power
changeover or power outage) the fans will begin to
run immediately
to their last received command once power is restored.
Once the controller reboot cycle is completed (and
the Modbus network is online), the fan speed will
be managed by the system controller.
1.4.8 Temperature/Humidity Sensor
As a standard, a temperature/humidity (T/H)
sensor is factory mounted in the return air stream
for room air control. The T/H sensor monitors the
return air conditions and provides input signal(s)
to the system controller to manage the operation
of the A/C unit
consistent with the set points entered in the
controller. As an option, sensor(s) may be shipped
loose for field installation. Refer to the electrical
drawing supplied with your unit for details specific to
your system. See Section 2.6.4.1 for descriptions of
the types of T/H control methods that may be utilized.
1.4.9 Heaters
The precision A/C unit incorporates heaters for re-
heating the supply air as required to offset the
sensible cooling of the system during the
dehumidification cycle and for the automatic heating
mode. As a standard, electric resistance heating
elements are factory installed in the supply airstream
to heat the supply air.
As an option, hot water reheat may be selected. A
hot water heating coil is factory installed in the
supply air stream to heat the supply air. A control
valve is
provided to regulate the flow of hot water through the
coil to maintain the reheat temperature to the control
setpoint.
1.5 Optional Equipment
1.5.1
Humidifier
STULZ CyberAir systems may be equipped with
an optional electrode steam humidifier. For this
option
a humidifier is installed inside the air conditioner with
automatic fill and drain valves and associated piping.
Operation of the humidifier’s fill and drain cycles is
based on water conductivity and is maintained by the
humidifier controller. An operating manual for the
humidifier is provided under separate cover. Refer to
that manual for detailed information on the operation
and maintenance of the humidifier.
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