Rev.01 03-27-17
Page 11 of 67
Compu-Aire
3.0
SEQUENCE OF OPERATIONS
3.1
Standard Units in General
In general, the controller is operated as follows. Note that the followings are applicable while the
controller is in active mode and only apply to DX and Chilled Water units.
•
Fan starts up on demand for cooling, heating, humidifying or dehumidifying, or operates
continuously
•
Sequences the compressors on in stages with adjustable delays to meet demand for
specified temperature and humidity setpoints.
•
Sequences the heaters on in stages with programmable delays to meet demand for heating
or reheat during dehumidification mode
•
Activates the humidifier as needed to meet the humidity demand
•
Dehumidification is achieved by means of cooling to reduce the humidity level. During the
dehumidification process, if the temperature falls below the room set point, heating is
brought on to reheat the air and maintain room temperature.
•
The controller monitors the complete system for any sensors, fans, compressors, heaters
and humidifier failure. Upon critical failures, the complete system will shut down with
alarm. For certain component failures, the applicable feature is disabled to insure safe
operation. For example, when compressor failure occurs, the failed compressor shall be
locked out but the system shall provide cooling by other compressor if available. On a
heater failure, the heaters are locked out. The system will not use that function until
manually reset on the display. The controller also keeps the history of last 100 alarms after
you reset them.
3.2
How to Turn the Unit ON
•
From the status screen, navigate to the On/Off menu and press enter. Use the Up/Down
arrow buttons to toggle the On/Off operation.
•
The System Status screen should indicate the current system operating mode
•
Default time delay for evaporator fan is 30 seconds to avoid short cycling
•
Unit will automatically control the necessary mode of operation to maintain room setpoints
3.3
Lead/Lag Redundancy
–
cLAN Network
System 2500+ series controllers can be set for n+1 redundancy setup. A maximum of 32 units can
be linked together on the cLAN network. The cLAN networked systems are identified with IP
address numbers. Any system within the network can be configured as master unit. This
alleviates the need to cumbersome wiring with the use of stand card Ethernet cables. In case of
master unit is out of service, any of the slave unit can be set as a new master from a few its own
interface. No wiring changes are needed. Each controller is self-dependent with necessary
sensors and it can be used as a stand-alone unit. When used on the cLAN Network, each unit are
not required to have to have the same software revision and date.
