036-21490-002-A-0204
8
Unitary Products Group
FEATURES
All models are available with a wide variety of factory-
mounted options such as stainless steel heat exchangers,
phase monitor, dirty filter switch, and coil guard to make them
suitable for almost every application.
All units are self-contained and assembled on full perimeter
base rails with holes in the four corners for overhead rigging.
Every unit is completely piped, wired, charged and tested at
the factory to simplify the field installation and to provide
years of dependable operation.
All models (including those with an economizer) are suitable
for either bottom or horizontal duct connections. Models with
factory installed power exhaust are suitable for bottom
duct connections only. For bottom duct, you remove the
sheet metal panels from the supply and return air openings
through the base of the unit. For horizontal duct, you replace
the supply and return air panels on the rear of the unit with a
side duct flange accessory.
All models are available with these “factory mounted” outdoor
air damper options:
•
Single enthalpy economizer
•
Single enthalpy economizer with power exhaust
•
Motorized outdoor air damper
A fixed outdoor air intake assembly will be shipped in the
return air compartment of all units ordered without an econo-
mizer or motorized outdoor air damper option. The assembly
includes a rain hood with a damper that can be set for 10, 15
or 25% outdoor air. With bottom duct connections, the intake
damper assembly should be mounted over the opening in the
return air panel. With horizontal ductwork, it should be
mounted on the return air duct.
All supply air blowers are equipped with a belt drive that can
be adjusted to meet the exact requirements of the job. A high
static drive option is available for applications with a higher
CFM and/or static pressure requirement.
All compressors have internal pressure relief. Every refriger-
ant circuit includes an expansion valve, a liquid line filter-
drier, a discharge line high pressure switch and a suction line
with a freezestat and low pressure/loss of charge switch to
protect all system components.
•
Simplicity
™ Controls -
Simplicity
™ control boards have
standardized a number of features previously available
only as options or by utilizing additional controls.
•
Low Ambient - An integrated low-ambient control
allows all units to operate in the cooling mode down
to 0ºF outdoor ambient without additional assis-
tance. Optionally, the control board can be pro-
grammed to lockout the compressors when the
outdoor air temperature is low or when free cooling
is available.
•
Anti-Short Cycle Protection - To aid compressor
life, an anti-short cycle delay is incorporated into the
standard controls. Compressor reliability is further
ensured by programmable minimum run times. For
testing, the anti short cycle delay can be temporarily
overridden with the push of a button.
•
Fan Delays - Fan on and fan off delays are fully pro-
grammable. Furthermore, the heating and cooling
fan delay times are independent of one another. All
units are programmed with default values based
upon their configuration of cooling and heat.
•
Safety Monitoring - The control board monitors the
high and low-pressure switches, the freezestats, the
gas valve, if applicable, and the temperature limit
switch on gas and electric heat units. The unit con-
trol board will alarm on ignition failures, compressor
lockouts and repeated limit switch trips.
•
Nuisance Trip Protection and Strikes - To prevent
nuisance trouble calls, the control board uses a
“three times, you’re out” philosophy. The high and
low-pressure switches and the freezestats must trip
three times within two hours before the unit control
board will lock out the associated compressor.
•
On Board Diagnostics - Each alarm will energize a
trouble light on the thermostat, if so equipped, and
flash an alarm code on the control board LED. Each
high and low-pressure switch alarm as well as each
freezestat alarm has its own flash code. The control
board saves the five most recent alarms in memory,
and these alarms can be reviewed at any time.
Alarms and programmed values are retained
through the loss of power.
All units have long lasting powder paint cabinets with 750
hour salt spray test approval under ASTM-B117 procedures.
All models are CSA approved.
•
Warranty - All models include a one-year limited parts
warranty on the complete unit. Compressors and electric
heater elements carry a five-year warranty.
•
Electric Heat Operation - All electric heat models (fac-
tory installed only) are wired for a single power source
and include a bank of nickel chromium elements
mounted at the discharge of the supply air blower to pro-
vide a high velocity and uniform distribution of air across
the heating elements. Every element is fully protected
against excessive current and temperature by fuses and
two thermal limit switches.
The power supply wiring can be routed into the control
box through a threaded pipe connection in the base pan
of the unit or through a knockout in the wiring panel on
the front of the unit.
