Desert Aire SelectAire Plus SP Series, Installation And Operation Manual

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Desert Aire - SP Manual
The SP dehumidifiers are equipped with a local man-machine interface on the face of the unit
controller located inside the electrical box of the unit. A separate, optional remote display terminal
can be ordered for service or remote access. See the controller manual for details on wiring and
environmental limits.
Most proportional valves have either three or four terminals for field-installed wiring.
• Four-terminal valves have two terminals for 24 VAC power and two terminals for the
signal input.
• Three-terminal valves have one terminal for the “hot” 24 VAC input, a second terminal for
the “positive” signal input, and a third, common terminal for the “neutral” 24 VAC input and
the “negative” signal input.
You must follow the instructions included with the valve cut sheet. Observe the proper polarity, or you
may damage both the valve and the Desert Aire controller. See the unit wiring schematics for
information on signal wire connection points.
When the proportional signal is ordered, the binary heating output acts as an interlock. This can be
used to activate a pump, valve, or interlock that needs to be coordinated with the proportional heating
signal. The contact rating is shown on the electrical schematic. Use a transformer and relay to
energize loads that are higher than the contact rated current draw or power.
2.10 Gas Heater (Optional)
2.10.1 Gas Heater Installation Safety
The Desert Aire dehumidifier may be equipped with an optional Category III gas-fired heater to provide air
heating during the winter months. You must read and understand the following guidelines and warnings
before you connect the heating section. Failure to follow these guidelines can result in improper and unsafe
operation of this equipment, which can cause severe personal injury, death, or substantial property damage.
Observe the following precautions:
• Follow all appropriate national and local code and guidelines when installing gas-heating
equipment. Failure to follow CGA, NFPA, and/or ANSI standards may cause equipment damage,
personal injury, or death.
• Corrosive environments may reduce heater service life. This furnace is not to be used for
temporary heating of buildings or structure under construction. Many of the chemicals used during
construction form acid-bearing condensate when burned. This can substantially reduce the life of
the heat exchanger.
• Gas heating equipment located indoors requires adequate combustion air. If you install the
equipment inside a penthouse or mechanical room, an indoor unit heater and terminal kit must be
used.