036-21539-003-B-030520 Unitary Products Group• SMOKE DETECTORS - (supply air & return air) Thesmoke detectors stop operation of the unit by interruptingpower to the control board if smoke is detected within theair compartment.• COIL GUARD - Customers can purchase a coil guard kitto protect the condenser coil from damage. This is not ahail guard kit.• STAINLESS STEEL HEAT EXCHANGER - For applica-tions in corrosive environments, this option provides afull stainless steel heat exchanger assembly.• STAINLESS STEEL DRAIN PAN - An optional rust-proofstainless steel drain pan is available to provide years oftrouble-free operation in corrosive environments.• PHASE MONITORS - Designed to prevent unit damage.The phase monitor will shut the unit down in an out-of-phase condition.• HIGH SPEED DRIVE - May include a belt, blower pulley,motor pulley or a motor change to enhance blower per-formance.• DIRTY FILTER SWITCH - This kit includes a differentialpressure switch that energizes the fault light on the unitthermostat, indicating that there is an abnormally highpressure drop across the filters. Factory installed optionor field installed accessory.• HINGED FILTER DOOR/”TOOLLESS” BLOWER ANDACCESS PANELS (not hinged) - This option allows foreasy access and maintenance.NOTE:Knobs are shipped separately within the unit toprevent shipping damage. These must be fieldinstalled for toolless operation.• LOW SPEED DRIVE - Includes a motor change whenhigh airflow is not required. (DR300 only)FIELD-INSTALLED ACCESSORIES• SINGLE INPUT ELECTRONIC ENTHALPY ECONO-MIZERS - Includes a slide-in / plug-in damper assemblywith fully modulating spring-return motor actuator capa-ble of introducing up to 100% outdoor air with nominal1% leakage type dampers.The enthalpy system contains one sensor that monitorsthe outdoor air and determines when the air is coolenough and dry enough to provide free cooling.The rainhood is painted to match the basic unit and mustbe field-assembled before installing.Power exhaust is not available as a field installedoption.• MOTORIZED OUTDOOR AIR INTAKE DAMPER -Includes a slide-in / plug-in damper assembly with a 2-position, spring return motor actuator which opens tosome pre-set position whenever the supply air blower isoperating and will drive fully closed when the blower unitshuts down.The rain hood is painted to match the basic unit andmust be field-assembled before installing.Power exhaust is not available as a field installed option.• ROOF CURBS - Fourteen-inch high roof curbs provide awater-tight seal between the unit and the finished roof.These full perimeter curbs meet the requirements of theNational Roofing Contractors Association (NRCA) andare shipped knocked-down for field assembly.They're designed to fit inside the base rails of the unitand include both a wood nailing strip and duct hangersupports.• HIGH ALTITUDE NATURAL GAS - Burner orifices andpilot orifices are provided for proper furnace operation ataltitudes up to 6,000 feet.• PROPANE - Burner orifices, pilot orifices and gas valveparts are provided to convert a natural gas furnace topropane.• HIGH ALTITUDE PROPANE - Burner orifices and pilotorifices are provided for proper furnace operation at alti-tudes up to 6,000 feet. This accessory supplements thebasic propane conversion kit.• SIDE DUCT FLANGES - One-inch flanges replace thesupply and return air panels on the rear of the unit toaccommodate horizontal duct connections. Theseflanges can also be used individually for bottom supply/horizontal return or horizontal supply/bottom return. Theycannot be used on units with power exhaust.• BAROMETRIC RELIEF DAMPER - This damper acces-sory can be used to relieve internal building air pressureon units with an economizer without power exhaust. Thisaccessory includes a rain hood, a bird screen and a fullyassembled damper. With bottom duct connections, thedamper should be mounted over the opening in thereturn air panel. With horizontal ductwork, the accessoryshould be mounted on the return air duct.• ENTHALPY ACCESSORY CONTROL KIT - This kitcontains the required components to convert a singleenthalpy economizer to dual enthalpy.• BURGLAR BARS - Mount in the supply and returnopenings to prevent entry into the duct work.• FLUE EXHAUST EXTENSION KIT - In locations withwind or weather conditions which may interfere withproper exhausting of furnace combustion products, thiskit can be installed to prevent the flue exhaust fromentering nearby fresh air intakes.• WOOD SKID - Allows unit to be handled with 90” forks.• CO 2 SENSOR - Senses CO2 levels and automaticallyoverrides the economizer when levels rise above thepresent limits.• COIL GUARD - Customers can purchase a coil guard kitto protect the condenser coil from damage. This is not ahail guard kit.• PHASE MONITORS - Designed to prevent unit damage.The phase monitor will shut the unit down in an out-of-phase condition.