Page 50 of 8012.3 Basic Sequence of OperationAll sequence of operation information for units controlledwith ALC controls is available in the ALC Sequence ofOperation documents that can be requested from yourmanufacturer’s Addison representative for each specific job.• Sequence of operation information specifically for theoperation of the electric heater modules within theabove referenced document.For sequence of operation information for units controlledwith field-supplied DDC controls (whether factory-mounted or field-mounted), consult the DDC controlsmanufacturer and/or installer.12.4 Accessory Controls OptionsAccessory controls options include, but are not limited to:• Carbon Dioxide Detector: This option provides aroom-mounted carbon dioxide detector for initiatingadditional outdoor ventilation.• Clogged Filter Indicator: This section provides adifferential pressure switch and status indication.• Exhaust Fan Interlock: This option provides aninterlock between an exhaust fan and the unit.• Firestat: This option de-energizes the unit whenthe stat, mounted in the return air section, sensesreturn air above 135 °F (57.2 °C). The firestat must bemanually reset.• Freezestat: This option shuts down the unit whenthe discharge temperature falls below thecontroller’s setpoint.• Service Receptacle: This option provides a 115Vservice receptacle with 15A breaker. It is mounted in a2” x 4” (51cm x 10.2cm) enclosure. It can be field-wiredor factory-wired (outdoor condensing section only).• Smoke Detector: This option provides an ionizationtype supply air smoke detector which shuts off theunit if smoke is detected.RC/FC Series Installation, Operation, and Maintenance Manual