ICP *9MPT050F12 Installation Instruction

Contents

440 01 2021 0136furnace will automatically shift to the high Heat mode for the re-maining duration of the heating cycle.For 2--stage thermostat installations, the R, W1 and W2 wiresfrom the thermostat connect to the R, W1 and W2 connections onthe furnace control. Set TT Dip switch (SW1--3) to ON position.During operation, the furnace will shift from Low Heat to high Heatas requested by the thermostat.Set thermostat heat anticipator in accordance with the TechnicalSupport Manual.Heat anticipator setting will need to be measured if 24VAC humidi-fier is installed. Measure currentin series from R to W1 at the ther-mostat. Be sure 24VAC humidifier is wired up to control. Allowfurnace to operate for 2 minutes before recording the AC amper-age reading. Set anticipator on thermostat to recorded value.Thermostat location has an important effect on the operation of thefurnace. Follow instructions included with thermostat for correctmounting and wiring.Low voltage connections to furnace must be made on terminalboard to furnace control. (See Figure 39)If cooling is used, the Y and G from the thermostat must be con-nected to the control board Y and G to energize cooling blowerspeed.Optional EquipmentAll wiring from furnace to optional equipment MUST conform to lo-cal codes or, in the absence of local codes with the latest edition ofThe National Electric Code, ANSI NFPA 70 and/or The CanadianElectric Code CSA C22.1. Install wiring in accordance withmanufacturerís instructions. The wiring MUST have a minimumtemperature rating of 105 C. codes or, in the absence of localcodes, the applicable national codes. Install wiring in accordancewith manufacturerís instructions.Humidifier/Electronic Air CleanerThe furnace is wired for humidifier and/or electronic air cleanerconnection.!REDUCED FURNACE LIFE HAZARDFailure to follow caution may result in reducedfurnace life.Do NOT exceed 115V/1.0 amp. maximum currentload for both the EAC terminal and the HUMterminal combined.CAUTIONHUMIDIFIER -- The HUM (115) is energized when the pressureswitch closes on a call for heat. The HUM is energized whenthe inducer is energized.ELECTRONIC AIR CLEANER -- EAC is energized when thereis a blower speed call, except is NOT energized when bloweroperates in the hard--wired continuous fan mode.Furnace ControlThe furnace control is preset at the factory with a fixed blower ONdelay of 30 seconds in the heating mode. The blower OFF timing ispreset at 140 seconds. If desired, the fan OFF delay can be reset toobtain the longest delay times while still maintaining comfort lev-els. See ìFurnace Wiring Diagramî.Dehumidification -- Variable Speed ONLY (*9MPV)The furnace control is wired for 24 VAC normally--open (N/O) de-humidistat connection. Connect dehumidistat to the Y terminaland the 1/ 4 male quick connect Dehum terminal on the furnacecontrol (See Figure 39 and “Furnace Wiring Diagram”.) A 20% re-duction of cooling airflow will occur when the Dehum dehumidistatterminal is energized by being connected to Y during a call for cool-ing from the thermostat.W2Low VoltageTerminal BoardW2Figure 38 Electrical ConnectionsNOTE: Junction Box can be mounted to either the left or right side.25--24--78aNOTE: 115 VAC/60Hz/single--phaseOperating voltage range*: 127 VAC max, 104 VAC min.* Permissible limits of voltage at which unit will operate satisfactorilyConnectionBoxNEUT.HOTGround115V. 60 Hz.WBKGRCW1RWRR W1W1YYGG Single StageThermostatGGLow VoltageTerminal BoardTwo StageThermostatW2Furnace Control FuseThe 24V circuit contains a 5--amp, automotive--type fuse locatedon furnace control board. (See Figure 39) Any electrical shorts of24V wiring during installation, service, or maintenance may causefuse to blow. If fuse replacement is required, use only a fuse ofidentical size (5 amp.)