Introduction
SS-SVX002B-EN
11
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.
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 Modbus signal. 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 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:
•
Locked rotor
•
Low main supply voltage
•
Loss of a phase
•
Over-heating of electronics
•
Over-heating of motor
If a communication loss occurs, the fans will run at their
last received output command until a new 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.
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
Temperature/Humidity Sensor,” p. 22
the types of T/H control methods that may be utilized.
Optional Equipment
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.
Humidifier
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.
Condensate Pump
An optional condensate pump may be factory installed.
The pump automatically eliminates condensate and
humidifier flush water (if applicable) from the drain pan.
An internal overflow safety switch is wired to the system
controller to automatically signal an alarm should an
overflow occur.
Water Detector
As an option, a spot type or strip/cable type water
detectors (see Section
“Remote Water Detector,” p. 23
Upon sensing a leak, the water detector control circuit will
signal the system controller of the alarm condition.
Smoke Detector
Optionally mounted in the return air stream, a photo-
electric smoke detector is used to sense the presence of
smoke and signal the controller when a smoke alarm
condition exists. The system controller is programmed to
shut down the compressor and the fans when smoke is
detected. When the alarm condition is cleared, a manual
re-set is required by cycling the main power service
disconnect switch off and on.
Firestat
Optionally mounted in the return air stream, a fire detector
senses high return air temperature and signals the
controller when a fire alarm condition exists. The system
controller is programmed to shut down the compressor
