Carrier Performance 48VR-A Installation Instructions Manual

Also see for Performance 15 48VR-A: Owner's information manual Owner's information manual

Contents

29Table 8 – Color Coding for Indoor Fan Motor LeadsBlack = High SpeedOrange = Med --- High SpeedRed = Med SpeedPink = Med --- Low SpeedBlue = Low SpeedSelection of Proper Fan Speeds for OperationModes:NOTE: All models are factory--shipped for nominal high stageand low stage cooling airflow operation at minimum external staticpressure. Many models are factory--shipped for nominal high stageand/or low stage gas heating airflow at minimum external staticpressure. Table 10 provides airflow data for higher external staticpressures.Low Stage Gas Heating: Table 10 shows the suitability of eachspeed for a given external static pressure for low stage gas heating.Any speed/static combination that is outside the rise range ismarked “NA” and must not be used. The unit must operate withinthe low stage gas heat rise range printed on the rating plate.Connect the chosen fan speed wire to “LO HEAT” connection onthe IGC Board (see Fig. 18).High Stage Gas Heating: Table 10 shows the suitability of eachspeed for a given external static pressure for high stage gas heating.Any speed/static combination that is outside the rise range ismarked “NA” and must not be used. The unit must operate withinthe high stage gas heat rise range printed on the rating plate.Connect the chosen fan speed wire to “HI HEAT” connection onthe IGC Board (see Fig. 18).Low Stage Cooling/Heat Pump: Using Tables 11, 12, and 13,and the nominal airflow for low stage cooling (Table 1) find theexternal static pressure drops for wet coil, economizer, and filter,and add them to dry coil measured on the system. Using this totalstatic pressure, use Table 10 to find the airflows available at thetotal static pressure. Connect the chosen fan speed wire to “LOCOOL” connection on the IGC Board (see Fig. 18).High Stage Cooling/Heat Pump:Using Tables 11, 12, and 13,find the external static pressure drops for wet coil, economizer, andfilter, and add them to dry coil measured on the system. Using thistotal static pressure, use Table 10 to find the airflows available atthe total static pressure. The speed chosen must provide airflow ofbetween 350 to 450 CFM per ton of cooling. Connect the chosenfan speed wire to “HI COOL” connection on the IGC Board (SeeFig. 18).High Stage Enhanced Dehumidification Cooling: Using thetotal static pressure for selecting the high stage cooling speed, useTable 10 to find lower speed/airflows available at that total staticpressure. All airflows highlighted in Table 10 are acceptable forDehum speed. The speed chosen must provide airflow of between320 to 400 CFM per ton of cooling. Connect the chosen fan speedwire to “DHUM” connection on the IGC Board (see Fig. 18).To activate the high stage enhanced dehumidification coolingmode, the shunt jumper in Fig. 18 must be moved from the No DHto DH selection (See Fig. 18, close up).Continuous Fan (All models): Continuous fan speed is the samespeed as Low Stage Cooling.Using the Same Fan Speed for More than One Mode: Some fanspeeds are ideal for more than one mode of operation. It ispermissible to use a field--supplied jumper wire to connect onespeed tap wire to two or more speed connections on the ignitionboard (IGC). Jumper wires must use 18 AWG wire with at least2/64” insulation.Cooling Sequence of Operationa. Continuous Fan(1.) Thermostat closes circuit R to G energizing theblower motor for continuous fan. The indoor fan isenergized on low speed.b. Cooling Mode(1.) Low Stage: Thermostat closes R to G, R to Y1and R to O. The compressor and indoor fan areenergized on low speed. The outdoor fan is alsoenergized.(2.) High Stage: Thermostat closes R to G, R to Y1, Rto Y2 and R to O. The compressor and indoor fanare energized on high speed. The outdoor fan isalso energized.c. Heat Pump Mode(1.) Low Stage: Thermostat closes R to G, R to Y1.The compressor and indoor fan are energized onlow speed. The outdoor fan is also energized.(2.) High Stage: Thermostat closes R to G, R to Y1, Rto Y2. The compressor and indoor fan are ener-gized on high speed. The outdoor fan is also ener-gized.d. Defrost Mode(1.) Outdoor Fan is disabled, thermostat closes R to Oand R to W1. Low stage gas heat tempers the leav-ing air. When defrost is complete, unit will returnto heating mode. If room thermostat is satisfiedduring defrost, unit will shut down and restart indefrost on next call for heat.Step 4 — Defrost ControlQuiet ShiftQuiet Shift is a field--selectable defrost mode, which will eliminateoccasional noise that could be heard at the start of defrost cycle andrestarting of heating cycle. It is selected by placing DIP switch 3(on defrost board) in ON position.When Quiet Shift switch is placed in ON position, and a defrost isinitiated, the following sequence of operation will occur. Reversingvalve will energize, outdoor fan will turn off, compressor will turnoff for 30 sec and then turn back on to complete defrost. At thestart of heating after conclusion of defrost reversing valve willde--energize, compressor will turn off for another 30 sec, and theoutdoor fan will stay off for 40 sec, before starting in the Heatingmode.DefrostThe defrost control is a time/temperature control which includes afield--selectable time period (DIP switch 1 and 2 on the board)between defrost cycles of 30, 60, 90, or 120 minutes (factory set at60 minutes). To initiate a forced defrost, two options are availabledepending on the status of the defrost thermostat.48VR-- A