Manuals / Carrier / Household Appliance / Air Conditioner

Carrier JK034-074 Ð Accessory Relay Board Standard Factory Supplied, Ð Enthalpy Sensor Location

Models: 48FK 50FK JK034-074

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Fig. 15 Ð Accessory Relay Board

LEGEND

ECON Ð Economizer

MIN Ð Minimum

PÐ Potentiometer

VAV Ð Variable-Air Volume

Fig. 15 Ð Accessory Relay Board

(Standard; Factory Supplied)

		LEGEND
IC	Ð	Integrated Circuit
IN	Ð	Input

PÐ Potentiometer RTN Ð Return

Fig. 16 Ð Two-Step Demand Limit Module

Fig. 17 Ð Enthalpy Sensor Location

Variable Frequency Drive (VFD) Ð The optional VFD is used to modulate supply fan air¯ow to maintain duct static pressure on VAV applications. The VFD is located in the supply fan section (see Fig. 18 and 19), and can be ac- cessed by opening the fan section access door.

The unit is supplied with a pressure transducer capable of measuring from 0.0 to 5.0 in. wg. The pressure transducer will send a 4 to 20 mA signal to the VFD to modulate the speed of the indoor fan motor to precisely control the fan to the desired static pressure set point. The VFD is factory set at 2.5 in. wg duct static pressure. Refer to the Operating Se- quence section for more information on the VFD.

The VFD has been programmed and wired at the factory for this application. No further adjustments (except for Duct Static Pressure Set Point) should be necessary at start-up. Factory jumper wire con®gurations are shown in the Supply Fan Control with VFD Option section on page 28.

A separate service manual for the factory-installed VFD is supplied with each unit. Refer to the VFD manual for more information on the VFD controls.

Temperature Reset Ð Accessory temperature reset al- lows the unit to automatically adjust (``reset'') the supply- air temperature set point to a higher value once most of the space cooling load has been met. When the space conditions are satis®ed, the VAV terminals will close to the minimum position. All VAV units will sense the decrease in actual supply- air temperature and the unit controls respond by reducing

Fig. 18 Ð Variable Frequency Drive,

Sizes 034-048 and 078-104

Fig. 19 Ð Variable Frequency Drive, Sizes 054-074

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Carrier JK034-074, 50FK, 48FK Ð Accessory Relay Board Standard Factory Supplied, Ð Two-Step Demand Limit Module

Contents

Controls Operation and Troubleshooting 48FK,JK034-074 50FK,FY,JK,JY034-104 Variable-Air Volume Rooftop UnitsCONTENTS cont SAFETY CONSIDERATIONSGENERAL Table 1 Ð Pin Terminal Connector J1 Thermistor Inputs Return-Air TemperatureFig. 1 Ð Processor Board Fig. 3 Ð Pin Terminal Connector J2 Status Switch InputsFig. 2 Ð Pin Terminal Connector J1 Thermistor Inputs Table 2 Ð Pin Terminal Connector J2 Status Switch InputsThe potentiometer locations and functions are as follows Table 3 Ð Output Pin and Terminal Assignments Fig. 5 Ð Relay BoardCompressor Operation Fig. 8 Ð Thermistor T1 Location, 50FK,JK034-048 Units GAS SECTIONHORIZONTAL SUPPLY SECTION 48FK,JK ONLYFig. 9 Ð Thermistor T1 Location, 48FK,JK, 50JY and 50JKX,JKY 054-074 Units and 50FKX,FKY and 50FY054-104 UnitsFig. 10 Ð Thermistor T1 Location, 50FK,JK054-074 Units GAS SECTIONFig. 11 Ð Thermistor T2 Location, Size 034-048 Units Fig. 12 Ð Thermistor T2 Location, Size 054-104 UnitsFig. 13 Ð Thermistor T3 and T4 Locations Size 034-048 Units STANDARDFig. 14 Ð Thermistor T3 and T4 Locations, Size 054-104 Units 054 UNITS 064, 074, 078 UNITS 088, 104 UNITSFig. 15 Ð Accessory Relay Board Standard Factory Supplied Fig. 16 Ð Two-Step Demand Limit ModuleFig. 17 Ð Enthalpy Sensor Location Fig. 18 Ð Variable Frequency Drive Sizes 034-048 andCONTROLS INSTALLATION Space Temperature ResetFig. 20 Ð Unit Control Box Arrangement, Sizes Fig. 21 Ð Unit Control Box Arrangement, Sizes Fig. 22 Ð Unit Control Box Arrangement, Sizes 088 and Fig. 23 Ð Occupied/Unoccupied Switch with Night Setback Thermostat Fig. 25 Ð Accessory Reset BoardVoltage Drop Characteristics Fig. 24 Ð Heat Interlock RelayFig. 26 Ð Space Temperature Sensor Averaging Fig. 29 Ð 115-Volt Field Wiring to Accessory Fig. 27 Ð Single-Step Demand LimitFig. 28 Ð Two-Step Demand Limit Module 2-Step Demand Limit Control ModuleThis emulation requires the following eld-supplied parts Fig. 30 Ð Remote SASP Wiring Fig. 31 Ð External Alarm IndicationP Ð Manual Potentiometer R Ð Fixed Resistor Field Wiring R Ð Resistor Factory Installed Factory Wiring Field WiringTable 6 Ð Smoke Control Switches Required for Each Mode Modulating PowerTable 5 Ð Smoke Control Modes FireTable 7 Ð Switch Functions Modulating Power ExhaustTable 8 Ð Tubing Size SIZE inFig. 32 Ð Smoke Control Wiring 034-048 UNITSALL UNITS Fig. 33 Ð Modulating Power Exhaust and Inlet Guide Vane Differential Pressure Switch SizesPressure Switch and Variable Frequency Drive Fig. 35 Ð Modulating Power Exhaust Differential Pressure Switch SizesTable 10 Ð Conguration Header and DIP Switch Factory Settings Table 9 Ð Potentiometer Inputs and RangesTable 11 Ð Conguration Header Jumpers Table 12 Ð DIP Switches Fig. 36 Ð Inlet Guide Vane Motor 50FK,JK034-074 Units Fig. 37 Ð Inlet Guide Vane Motor, 48FK,JK, 50FY,JYand 50FJX,FJY,FKX,FKY034-074 Units Fig. 38 Ð Inlet Guide Vane Motor Size 078-104 UnitsREAD STOP WRITE RESET Fig. 39 Ð Differential Pressure Switch for Inlet GuideModulating Power Exhaust Option Fig. 41 Ð Jumper Removal to Disable MotorModulating Power Exhaust Option or Acces Table 13 Ð VFD Set Point Frequency Command for Duct PressureTable 14 Ð Changing the VFD Set Point Frequency Command START UNIT Table 15 Ð Quick Test, Unit Conguration and Switch Check CONTROL SWITCHQUICK NORMALTable 16 Ð Quick Test, Thermistor and Potentiometer Check Table 17 Ð Quick Test, Output Relay CheckOPERATING INFORMATION Table 18 Ð Sensor Resistance Valueswarm-up routine, and a 26 will be displayed Fig. 42 Ð Component Arrangement, 034-048 Units 034 AND 038 UNITS044 AND 048 UNITS Fig. 43 Ð Component Arrangement, 054-104 Units 054, 064 UNITS074, 078 UNITS 088, 104 UNITS 104 UNITSSupply Fan Control with IGV Ð In most VAV units, the supply fan static pressure is controlled by inlet guide vanes. The inlet guide vanes operate independently from the micro- processor. The supply static pressure is controlled by a dif- ferential pressure switch. If the unit is equipped with a re- turn fan, building pressure is controlled by another differential pressure switch Fig. 44 Ð Modulating Power Exhaust Component Locations Sizes Fig. 45 Ð Modulating Power Exhaust Component Locations Sizes Page Table 19 Ð Compressor Loading and Unloading Sequences Table 19 Ð Compressor Loading and Unloading Sequences cont TROUBLESHOOTING Table 20 Ð Controls TroubleshootingTable 21 Ð Operation Status Codes Table 22 Ð Diagnostic Codes · Wiring Problem Ð If the circuit is open, a failure will be detected 82 to be displayed on display board when display button iswill be energized and an error code of 82 will be displayed ergize alarm light and cause an error code of 83 to be disPage Fig. 48 Ð Processor Board Test Points Fig. 49 Ð Relay Board Test PointsFig. 50 Ð Relay Board Pin Terminal Connector J9 Fig. 51 Ð Display Board Pin Terminal Connector J10Table 23 Ð Voltage Reading Table 24 Ð Pin Terminal Connector J1 Voltages Table 25 Ð Pin Terminal Connector J2 VoltagesStep 1 Ð Low-voltage relay resistance check Step 2 Ð High-voltage relay resistance checkTable 27 Ð Terminal Strip J5 Connector Resistance Reading Table 28 Ð Enthalpy Sensor CheckoutFig. 52 Ð Damper Motor Connection Diagram VAV 1. Disconnect all power to the unit and the VFDVariable Frequency Drive Table 29 Ð Carrier Default Program Parameter Values Frequency SettingsGr.Fb Gr.SFTable 30 Ð Required User Adjusted Defaults Table 31 Ð Motor Overload SettingsFig. 53 Ð Variable Frequency Drive Terminal Block Size 034-048 Units Fig. 54 Ð Variable Frequency Drive Terminal Block Size 054-104 UnitsLEGEND AND NOTES FOR FIG Page Page SERVICE TRAINING CALL FOR FREE CATALOGSTART-UP CHECKLIST II. PRELIMINARY CHECKLIST ITEMSCONTROL SETTINGS I. PRE-START-UPTEMPERATURES III. START-UPIV. NOTES ELECTRICAL