Desert Aire CM3550 Series, Installation And Operation Manual

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9
1 Installation
1.1 Introduction
Your Desert Aire controller is designed for precise monitoring and control of air temperature, relative
humidity (RH) and Dew Point (DP) within a conditioned environment.
This CM3550 control system is easy to install and operate. The controller itself is installed in the
electrical cabinet of the dehumidifier and features either an internal display terminal (IDT) or a remote
display terminal (RDT). This display allows viewing and adjustment of the unit’s sensors and set
points. It also indicates the operating status of major components inside the dehumidifier.
Most sensors and devices have been factory-installed and wired inside the dehumidifier. In most
cases, only connection to a remote condenser, electrical power connection, zone and supply air
sensors are required. Connection to the facilities computer network or building management system
may also be required.
The CM3550 controller features optional building automation access. This includes options for
network communication ability including BACnet IP, BACnet MS/TP, ModBus RTU and ModBus IP.
1.2 Sensor Installation
The CM3550 control system requires a zone mounted combination relative humidity and temperature
sensor. Mount this sensor in the conditioned space away from any hot spots but in an area that is
representative of the zone. Constant air flow across this sensor will help insure proper readings.
A supply air temperature sensor is also required. Mount this sensor in the air duct supply conditioned
air to the zone.
1.3 Auxiliary Air Heating Control Wiring
Note: you must use the Desert Aire CM3550 control system to control or interlock with the room
heating system. This prevents wide fluctuations in room air temperature. It also prevents the heater
from trying to heat the room while the dehumidifier is running in the cooling mode.
1.3.1 Auxiliary Heating - Dry Contact Closure
The standard Desert Aire CM3550 Controller provides a dry contact closure to operate the
auxiliary space heater. The contact closes to energize a heater (may be supplied by others)
which has its own power source.
Install two wires from the thermostat blocks on the heater to the terminals H1 and H2 in the
control panel of the dehumidifier. See your wiring schematic for connection details.
Note: Units with an internal electric air heater have an airflow proving switch installed
between the heater and the control enclosure. If an air heater is installed external to the unit,
provide an external airflow proving switch for protection of the heater.
Desert Aire - CM3550 Manual