Haier HSU09VHG(DB)-W Service Manual

Also see for 1U09ES2VHA: Installation manual

Contents

SEQUENCE OF OPERATIONPAGE 28ENGLISHSystem PowerThe 240 Volt AC power for the system connects to terminals1(N), 2(L), and ground of the outdoor unit terminal block. Thisterminal block also has terminals to connect power to theindoor unit.The voltage readings between terminals 1(N) and ground, andterminals 2(L) and ground should be 120 VAC. The voltagereading between terminals 1(N) and 2(L) should be 240 VAC.One additional connection on the terminal block (3) is for thecommunication wire between the indoor and outdoor units.NOTE: Mis-wiring of these connections may cause improperoperation or damage to system components.Cool ModeOverviewThe temperature control range in cooling mode is 60°F - 86°F.The temperature set by the remote control and the indoorunit ambient temperature sensor will determine if a call forcooling is needed. If a call for cooling is justified, the call iscommunicated from the indoor unit to the outdoor unit. Theindoor unit louver will open using a stepper motor, and theindoor fan will operate at the speed last set. The outdoor unitwill determine the position of the EEV and speed (frequency)of the compressor. There can be a delay of up to 3 minutesbefore the outdoor unit fan and compressor start.The speed of the indoor fan can be controlled manually bythe user or automatically by the system. The speed can bechanged between LOW, MEDIUM, and HIGH. The predeter-mined conditions for automatic control are as follows:(Tr= room temperature Ts= set temperature)High Speed: Tr ≤ Ts + 5.4°FMedium Speed: Ts + 1.8°F ≤ Tr < Ts + 5.4°FLow Speed: Tr ≤ Ts + 1.8°F or when the sensor is off.There will be a 2 second delay when manually controlling thespeed.The outdoor unit temperature sensors: outdoor ambient,defrost, suction line, and compressor discharge, used inconjunction with the indoor temperature sensors, indoorambient and tube, provide information to the outdoor controlboard to monitor the system and regulate the frequency ofthe compressor, EEV positioning, and outdoor fan speed toachieve the desired room temperature.When cooling has been satisfied, the outdoor unit compres-sor will turn off, followed by the outdoor fan. The indoor unitfan will continue to run.If the system detects a malfunction, it may shut down orshow an error code on the indoor unit display board and/oroutdoor unit main board LED.Indoor UnitTo enter the cool mode, point the infrared remote control atthe indoor unit and press the power button, then press theCOOL mode button if not already set to cool mode.The signals received by the infrared receiver are relayed tothe main board of the indoor unit to turn the system on andset it to cool mode.The indoor unit main board will activate the display of theindoor unit, illuminating the display, indicating the room tem-perature and current status of the unit.The indoor unit main board will signal the louver stepper mo-tor to open the louver to either a stationary position, or oneof several oscillating modes.As the louver opens, the indoor unit main board will power upthe indoor fan motor, operating the fan at the speed last set.The indoor fan motor has a feedback circuit which providesthe indoor unit main board with information for controllingthe speed of the fan motor.Temperature sensorsThe indoor unit has two sensors that provide temperatureinformation to the indoor unit main board. The sensors: anindoor ambient temperature sensor, and pipe temperaturesensor, are used for controlling the system during cool mode.The resistance values of the sensors will vary with tempera-ture. The resistance to temperature values can be foundusing a temperature / resistance chart specific to the sensorbeing checked.CommunicationThe indoor and outdoor unit main boards communicate via adigital signal on the wire connected to terminal 3 of each unit.A splice or break in this wire will cause a communication error.When a command is received from the remote control, theindoor unit main board communicates with the outdoor unitmain board via the terminal 3 wire to perform the requestedfunction.Outdoor unitUpon a request for cooling, the outdoor unit main board ap-plies power to the outdoor fan motorand compressor. Depending on system cycling, there maybe up to a 3 minute wait period before the compressor andoutdoor fan start.WARNING: Do not measure compressor voltages, damage tothe meter may result.If the ambient room temperature is less than the set tem-perature, yet higher than 2°F below the set temperature, thesystem will adjust the running frequency of the compressorautomatically according to changes in ambient temperature.