Heat Controller VMH09SC-1, VMH12SC-1, VMH24SC-1, VMH18SC-1 service manual Contents

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Service Manual	VMH Series	Heat Controller, Inc.

		CONTENTS
1.Safety Precautions			3
2.	Functions		8
3.	Dimensions		10
	3.1	Indoor Unit	10
	3.2	Outdoor Unit	11
4.	Refrigerant Cycle Diagram		12
5.	Wiring Diagrams		13
	5.1	Indoor Unit	13
	5.2	Outdoor Unit	14
6.	Installation Details		15
	6.1	Power Wiring	15
	6.2	Pipe length and elevation	16
	6.3	Pressure test and evacuation	17
7.	Operation characteristics		18
8.	Electronic functions		19
	8.1 Abbreviation		19
	8.2	Display function	19
	8.3	Main Protection	20
	8.4	Operation Modes and Functions	21
9.	Troubleshooting		35
	9.1	Indoor Unit Error Display	36
	9.2	Diagnosis and Solution	36

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Contents Inverter Single Zone Ductless Mini Split Heat Pump Contents  Installation PrecautionSafety Precaution  For installation, always contact the dealer  Caution  Use two or more people to lift and transport the product  Keep level even when installing the product Operational  Do not block the inlet or outlet of air flow Do not drink the water drained from the product Function Anti-freeze protection in coolingOutdoor unit Compressor delay Dimension Indoor UnitModel Dimension mm Outdoor UnitRefrigerant Cycle Diagram Indoor OutdoorWiring Diagrams VMH09SC-1 A-VMH12SC-1 VMH18SC-1 Installation details Pipe length and the elevation Single Zone V Series Inverter SystemPressure Test & Evacuation System Evacuation and ChargingOperation characteristics Display function Electronic functionAbbreviation Main Protection Operation Modes and Functions Preheat modeFan only mode Preheat terminationCooling Mode Compressor running rules Frequency decreases Holds Model CurrentIndoor fan running rules Condenser high temperature T3 protectionOutdoor fan rules Evaporator low temperature T2 protection Heating Mode Compressor running rulesT1-Ts-ΔT +5.0 +4.5 +3.5 +3.0 +2.5 +2.0 +1.5 +1.0 +0.5 I1HEAT I2HEAT I3HEAT Outdoor fan running rulesVMH12SC-1 Indoor fan rulesUnit TEL0 TEL1 VMH09SC-1 VMH18SC-1Defrost mode： Defrost Actions For 9K and 12K unit For 18K and 24K unit High evaporator coil temp.T2 protection Auto-modeDehumidify mode Forced operation functionTimer function Sleep function modeAutomatic front panel function Ionizer Clean Air functionAuto-Restart function Troubleshooting SafetyEeprom parameter error diagnosis and solution Indoor Unit Error DisplayDiagnosis and Solution VMH Series E3 Indoor or E7 Outdoor Igbt over current protection diagnosis and solution VMH Series 29 P3 Error Low Ambient Protection Inverter compressor drive error diagnosis and solutionKey parts checking Position Resistance ValueVMH Series Some frequently-used R-T data for T1, T2, T3 and T4 sensor 2012