Carrier 48FK Controls Operation And Troubleshooting

Carrier 48FK Controls Operation And Troubleshooting Manual pdf 26 page image

Table 9 — Potentiometer Inputs and RangesPOTENTIOMETER DESCRIPTION LOCATION CONTROLVALIDRANGE DEFAULT VALUEP1 Supply AirSet Point DisplayBoard 45 to 70 F 45 F if -22 F < P1 < 45 F70 F if P1 > 70 F OR IF P1 < -22 FP2* EconomizerPosition EconomizerMotor 0 to 100% None (0 if P2 is bad)P3 Reset Limit AccessoryBoard 0 to 80 F None (limited to 70 F maximum)P4† Demand Limit,Single-Step Main Control Box 0 to 100% NoneDLCM-P1 Demand Limit,2-StepDLCM Board 50 to 100% NoneDLCM-P2 DLCM Board 0 to 49% NoneP5* Minimum EconomizerPosition Accessory Board 0 to 100% NoneP6 Warm-UpSet Point Accessory Board 40 to 80 F 40 F if 0° F < P6 < 40 F OR IF P6 < 95 FOR IF P6 < 080 F if 80 F < P6 < 95 FP7** ResetTemperature Reset Board 40 to 100 F None*Optional factory-installed economizer is required. Potentiometer P2 is not a set point.†Accessory two-step demand limit module is required (which has 2 potentiometers), or a 5 to 20 k-ohmfield-supplied potentiometer is required for single-step demand limit.**Accessory temperature reset is required.NOTE: Potentiometers P1-P6 input data to pin terminal connector J3.Potentiometer P7 inputs data to pin terminal connector J1.Configuration Header — The configuration headeris a series of 8 small wires that are broken (open circuit) orunbroken (closed circuit) in a pattern to indicate several uniquecharacteristics of the unit. The configuration header is fac-tory set and should not be changed; changing the factory set-ting may cause the unit to malfunction.Before start-up, visually check the configuration headeragainst the factory setting for the unit size. See Table 10 forfactory settings. See Table 11 for purpose for each jumper.Table 10 — Configuration Header andDIP Switch Factory SettingsJUMPER ORSWITCH NO.UNIT SIZES034-038,048-088UNIT SIZE044UNIT SIZE104HeaderPositionSwitchPositionHeaderPositionSwitchPositionHeaderPositionSwitchPosition1 ▫ Off ▫ Off ▫ Off2 n Off n Off n Off3 n On/Off* n On/Off* n On/Off*4 ▫ On/Off* ▫ On/Off* n On/Off*5 ▫ Off ▫ Off ▫ Off6 n Off n On n On7 ▫ On ▫ Off ▫ Off8 n Off n Off n OffLEGENDDIP — Dual, In-Line Package▫ — Broken Jumper (open circuit)n — Unbroken Jumper (closed circuit)*Depending on factory-installed options or field-installed accessories.Table 11 — Configuration Header JumpersJUMPERNUMBER FUNCTION FACTORYSETTING MEANING1,2 Unit Type ▫ n VAV Rooftop Unit3,4,5 Qty Compressors n ▫ ▫ 2 Compressors6 Expansion Valve n TXV7 Power Frequency ▫ 60 Hz8 Not Used n No SignificanceLEGENDTXV — Thermostatic Expansion ValveVAV — Variable-Air Volume▫ — Broken Jumper (open circuit)n — Unbroken Jumper (closed circuit)DIP Switches — The DIP switches configure the unitfor several factory-installed options and field-installed ac-cessories, plus factory unloaders. The DIP switches are lo-cated under a plastic enclosure which must be removed foraccess. See Fig. 1. The switches can be field adjusted. Switchesmust only be adjusted when control power is deenergized.See Table 12 for DIP switch purposes and Table 10 for fac-tory settings of the switch positions.Disconnect control power before changing the settingsof the DIP switches. To disconnect control power, openthe control circuit breaker.26