Carrier 50TCQD14 Installation Instructions Manual

Also see for 50TCQD: Installation instructions

Contents

24Defrost — The defrost control mode is a time/temperaturesequence. There are two time components: Thecontinuous run period and the test/defrost cycle period.The temperature component is provided by DefrostThermostat 1 and 2 (DFT1 and DFT2) mounted on theoutdoor coil.The continuous run period is a fixed time period between theend of the last defrost cycle (or start of the current Heatingcycle) during which no defrost will be permitted. This periodcan be set at 30, 60, 90 or 120 minutes by changing thepositions of DIP switches SW1 and SW2 (see Fig. 37 andTable 6). The default run period is 60 minutes for size 14units.a50--- 9688Fig. 37 -- DIP Switch Settings — Defrost BoardShorting the jumpers for a period of 5 to 20 secondsbypasses the remaining continuous run period and placesthe unit in a Forced Defrost mode. If the controlling DFTis closed when this mode is initiated, the unit willcomplete a normal defrost period that will terminate whenthe controlling DFT opens or the 10 minute defrost cyclelimit is reached. If the controlling DFT is open when thismode is initiated, the Defrost cycle will run for 30seconds. Both modes end at the end of the Defrost cycle.Unit Without Thru--Base Connection Kit —Pass the thermostat control wires through the bushing onthe unit end panel. Route the wire through the snap--inwire tie and up to the web bushing near the control box.Route the wire through the bushing and into the bottomleft side of the control box after removing one of the twoknockouts in the corner of the box. Using a connector atthe control box to protect the wire as it passes into thecontrol box. Pull the wires over to the terminal strip at theupper left corner of the Central Terminal Board (CTB).Use the connector at the control box and the wire tie toensure that the thermostat wire is tight and will not bedamaged by contact with the condenser coil. See Fig. 38.NOTE: If thru--the--bottom connections accessory isused, refer to the accessory installation instructions forinformation on routing power and control wiring.C10018Fig. 38 -- Thermostat Wire RoutingHeat Anticipator Settings —Set heat anticipator settings at 0.14 amp for the first stageand 0.14 amp for second--stage heating, when available.Electric Heaters50TCQ units may be equipped with field--installedaccessory electric heaters. The heaters are modular indesign, with heater frames holding open coil resistancewires strung through ceramic insulators, line--break limitswitches and a control contactor. One or two heatermodules may be used in a unit.Heater modules are installed in the compartment belowthe indoor (supply) fan outlet. Access is through theindoor access panel. Heater modules slide into thecompartment on tracks along the bottom of the heateropening. See Fig. 39.UNIT DAMAGE HAZARDFailure to follow this caution may result in equipmentdamage.Not all available heater modules and single pointboxes may be used in every unit. Use only thoseheater modules that are UL listed for use in a specificsize unit. Refer to the label on the unit cabinet for thelist of approved heaters and single point boxes.CAUTION!