ICP *9MPT050F12 Installation Instruction

Contents

440 01 2021 0142Changing Blower Speed (*9MPT Models)ELECTRICAL SHOCK HAZARD.Failure to do so could result in death or personalinjury.Turn OFF power to furnace before changingspeed taps.! WARNINGNOTE: The speed taps that the manufacturer sets from the factoryfor this product are based on a nominal 400 CFM per ton coolingand the basic mid range on the temperature rise for heating.Since the manufacturer cannot establish the static pressurethat will be applied to the unit, it is the responsibility of the in-staller dealer/contractor to select the proper speed taps forthe application when the unit is installed.REDUCED FURNACE LIFE HAZARDFailure to properly set the air temperature rise mayresult in reduced furnace life.Use ONLY the following blower motor speed taps forsetting air temperature rise.Blower Motor Model SizesSpeed Taps Heat High Heat LowHi (BLK) All NoneMed--Hi (O) All AllMed Lo (BL All AllLo (R) None 125L20! CAUTIONIf it is necessary to change speeds, refer to steps below.1. Refer to Furnace Wiring Diagram for location of the heatingand cooling speed taps located on the furnace control aswell as location of unused blower motor speed leads. Usethe chart (Table 9) to determine the blower motor speedsettings.Table 9 Blower Speed ChartWire Color Motor SpeedBlack HighOrange* Med--HighBlue MediumRed Low* Med--High speed may not be provided on all models.2. Change the heat or cool blower motor speed by removing themotor lead from the ìHI Heat or Lo Heatî or ìCoolî terminaland replace it with the desired motor speed lead from the“M1” or “M2î location. Connect the wire previously removedfrom the ìHi Heat or Lo Heatî or ìCoolî terminal to the va-cated “M1” or “M2î terminal.3. If the same speed must be used for both heating and cooling,remove the undesired motor speed lead from the ìHi Heat orLo Heatî or “Coolî terminal and connect that lead to the openterminal at “M1” or “M2î location or tape off. Attach a jumperbetween the ìHi Heat or Lo Heatî and ìCoolî terminals andthe remaining motor speed lead.Note: When using the same speed on motors with (4) speedleads, it will be necessary to tape off the terminal of the motorspeed lead removed from the ìHi Heat or Lo Heatî or ìCoolîterminal with electrical tape since an open terminal will not beavailable at the “M1” or “M2î location.Continuous--Fan Operation using “G”*9MPT ModelsEnergizing the îGî terminal on the furnace control provides contin-uous fan operation. This is done by connecting the G terminal ofthe thermostat to the G terminal on the furnace control. When theFAN switch is turned from auto to ON the fan will operate continu-ously at îLO HEATî speed. EAC will be energized in this mode.NOTE: In heating, the fan will turn off during furnace ignition andwarm up then restart at heating speed.*9MPTV ModelsEnergizing the îGî terminal on the furnace control provides contin-uous fan operation. This is done by connecting the G terminal ofthe thermostat to the G terminal on the furnace control. When theFAN switch is turned from auto to ON the fan will operate continu-ously at îLO HEATî speed. EAC will be energized in this mode.NOTE: No hard--wired continuous fan mode option available forvariable speed applications.NOTE: In heating, the fan will continue to operate at continuous fanspeed until the furnace control calls for heat speed after warm--up.Then the fan will run at heat speed.Hard--Wired Continuous Fan Operation (*9MPT ONLY)A terminal is provided on the furnace control located in the circulat-ing air blower compartment for operation of the continuous fan op-tion. This connection is intended for the low speed motor tap, andhas a lower contact rating (8 amps) than the heat and cool taps.When the low speed blower lead is connected to this terminal, thiswill provide low speed blower operation whenever the other threespeeds (ìHi Heat or Lo Heatî or Cool) are not energized.Thoroughly check the system after modification to ensure theproper operation of the circulating air blower in all modes of opera-tion.Separate speed selections for Heat, Cool, andContinuous--FanConnect low speed lead from circulating air motor to the “Cont”terminal at the furnace control coard. The appropriate motor leadsshould already be connected to the ìHi Heat and Lo Heatî and“Cool” terminals.Heating and Continuous--Fan Speed the SameIf it is necessary to operate the low heating speed and continuous--fan speed using the same blower speed, connect a jumper be-tween the “Lo Heat” and “Cont” terminals on the furnace control.Note: There should be only ONE motor lead going to the “LoHeat” and “Cont” terminals.Hard Wired Continuous Fan OperationA terminal is provided on the furnace control board located in thecirculating blower compartment for operation of the continuous fanoption. This connection is intended for the low speed motor tap,and has a lower contact rating (8 amps) than the heat and cooltaps. When the low speed blower lead is connected to this termi-nal, this will provide low speed blower operation whenever the oth-er three speeds (Lo Heat or Hi Heat or Cool) are not energized.