Haier AW07LC2VHA Technical Overview

Also see for 2U18MS2VHB: Installation manual Service manual Installation manual Service manual

Contents

PAGE 11ENGLISHINTRODUCTIONOVERVIEW & INTRODUCTIONMulti-Zone Outdoor Multi-Zone OutdoorThe Control of the Outdoor Unit Expansion ValveWhen unit starts, the EEV valves will energize and change to astandard opening. When operation starts, the EEV will changeposition to keep the suction vapor superheat level at around10°F.When the unit is shut off the opening size of the expansionvalve of the indoor unit is 5 steps;Four-way valve controlFor the details of defrosting four-way valve control, see thedefrosting process.Under heating mode, the four-way valve opens. If thecompressor does not start or changes to a non-heatingmode, the compressor will be stopped for 2 minutes, and thenthe four-way valve will shift.When the compressor first startsThe compresor will start in low frequency. After a brief timedelay, the compressor will come up to operating speed tomeet the demand requirement for capacity.The outdoor fan control (exchange fan)When adjusting the fan speed, the unit should remain at eachspeed for 30+ seconds to avoid speed-change malfunctions.In Cooling Mode, the wait time between speed levels shouldbe 15 seconds.The outdoor fan control when in cooling or dehumidifyingmodeFive seconds after compressor starts, the outdoor fan willstart running at medium speed. After 30 seconds, it beginsto control the fans peed according to the temperatureconditions of the outdoor environment.Over-temperature Heat Mode Indoor CoilThe over-temperature routine will protect the system from excessive high indoor coil temperature during heat mode operation.The routine will initiate if the indoor coil temperature sensor reads temperatures in excess of 131F. Conditions that cause highindoor coil temperature include indoor fan failure, dirty indoor coil and operating the system in heat mode when outdoor airtemperatures exceed operating limit. (Too warm outside)Should this routine be initiated, the system will reduce compressor frequency until the indoor coil temperature reaches 117F.Once this is achieved, the system will return to normal operation.149°F131°F138°F117°F124°F