254599-YTG-C-0807
Unitary Products Group
23
steel for corrosion resistance and allowing minimum mixed
air entering temperature of 25°F. Burners shall be of the
inshot type, constructed of aluminum coated steel and con-
tain air mixture adjustments. All gas piping shall enter the unit
cabinet at a single location through either the side or curb,
without any field modifications. Integrated control boards
shall provide timed control of evaporator fan functioning and
burner ignition. Heating section shall be provided with the fol-
lowing minimum protection:
a.
Primary and auxiliary high-temperature limit switches.
b.
Induced draft motor speed sensor.
c.
Flame roll out switch.
d.
Flame proving controls.
e.
If any of the above safety devices trip, a LED (light-
emitting diode) indicator shall flash a diagnostic
code that indicates which safety switch has tripped.
ELECTRIC HEATING SECTION
An electric heating section, with nickel chromium elements,
shall be provided in a range of 5 thru 30 KW, offering two
stages of capacity - 16 KW and above on 208/230 volt heaters
and 20 KW and above on 460 and 575 volt heaters. The heat-
ing section shall have a primary limit control(s) and automatic
reset to prevent the heating element system from operating at
an excessive temperature. The heating section assembly
shall slide out of the unit for easy maintenance and service.
Units with Electric Heating shall be wired for a single point
power supply with branch circuit fusing (where required).
UNIT OPERATING CHARACTERISTICS
a.
Unit shall be capable of starting and running at 125°F
outdoor temperature, exceeding maximum load crite-
ria of ARI Standard 210/240. The compressor, with
standard controls, shall be capable of operation down
to 0°F outdoor temperature. Unit shall be provided
with fan time delay to prevent cold air delivery before
heat exchanger warms up (Gas heat only).
ELECTRICAL REQUIREMENTS
All unit power wiring shall enter unit cabinet at a single factory
provided location and be capable of side or bottom entry, to
minimize roof penetrations and avoid unit field modifications.
Separate side and bottom openings shall be provided for the
control wiring.
STANDARD LIMITED WARRANTIES
•
Compressor 5 Years
•
Heat Exchanger 10 Years
•
Electric Heat Element 5 Years
•
Other Parts 1 Year
OPTIONAL OUTDOOR AIR
(Shall be made available by
either/or):
•
ELECTRONIC ENTHALPY AUTOMATIC ECONO-
MIZER
- Outdoor and return air dampers that are inter-
locked and positioned by a fully-modulating, spring
return damper actuator. The maximum leakage rate for
the outdoor air intake dampers shall not exceed 2%
when dampers are fully closed and operating against a
pressure differential of 0.5 IWG. A unit-mounted potenti-
ometer shall be provided to adjust the outdoor and return
air damper assembly to take in CFM of outdoor air to
meet the minimum ventilation requirement of the condi-
tioned space during normal operation. During econo-
mizer operation, a mixed-air temperature control shall
modulate the outdoor and return air damper assembly to
prevent the supply air temperature from dropping below
55°F. Changeover from compressor to economizer oper-
ation shall be provided by an integral electronic enthalpy
control that feeds input into the basic module. The out-
door intake opening shall be covered with a rain hood
that matches the exterior of the unit. Water eliminator/fil-
ters shall be provided. Simultaneous economizer/com-
pressor operation is also possible. Dampers shall fully
close on power loss.
•
MOTORIZED OUTDOOR AIR DAMPERS
- Outdoor air
dampers are positioned by a 2-position, spring-return
damper actuator. The maximum leakage rate for the out-
door air intake dampers shall not exceed 2% when
dampers are fully closed and operating against a pres-
sure differential of 0.5 IWG. A unit-mounted potentiome-
ter shall be provided to adjust the outdoor damper
assembly to take in the design CFM of outdoor air to
meet the ventilation requirements of the conditioned
space during normal operation. Whenever the indoor fan
motor is energized, the dampers open up to one of two
pre-selected positions - regardless of the outdoor air
enthalpy. Dampers return to the fully closed position
when the indoor fan motor is de-energized. Dampers
shall fully close on power loss.
OTHER PRE-ENGINEERED ACCESSORIES AVAILABLE
•
ROOF CURB
- 14"and 8” high, full perimeter curb with
wood nailer (shipped knocked-down).
•
BAROMETRIC RELIEF DAMPER
- Contains a rain
hood, air inlet screen, exhaust damper and mounting
hardware. Used to relieve internal air pressure through
the unit.
•
PROPANE CONVERSION KIT
- Contains new orifices
and gas valve parts to convert from natural to L.P. gas.
One per unit required.
•
HIGH ALTITUDE - NATURAL GAS
- Contains orifices
required for applications between 2000 and 6000 feet
altitude.
•
HIGH ALTITUDE - PROPANE GAS
- Contains orifices
required for applications between 2000 and 6000 feet
altitude. Must be used with propane conversion kit.
•
LOW NOX
- Required to reduce the emission of nitrogen
oxides below 40 nanograms per joule.
