Drive Control System - Gree GMV-S120WL/A-S Service Manual

unit. Controller will adjust the compressor frequency according to the sensed
temperature.
 High pressure sensor is used to sense the discharge pressure of outdoor unit. Controller
will judge the corresponding fan speed, compressor frequency, electronic expansion
valve opening position according to the sensed high pressure. When the high pressure is
too high, unit will enter high pressure protection and controller will display the error code.
Unit won't start up.
 Low pressure sensor is used to sense the low pressure of outdoor unit. Controller will
judge the corresponding fan speed, etc. according to the sensed low pressure. When the
low pressure is too low, unit will enter low pressure protection and controller will display
the error code. Unit won't start up.
 The output of fan speed is controlled according to unit's operating mode, high pressure
value and low pressure value.
 The on and off of 4-way valve A is controlled according to unit's operating mode. It's used
to control heat exchanger of indoor unit.
 The on and off of 4-way valve B is controlled according to unit's operating mode. It's used
to control heat exchanger of outdoor unit.
 The main electronic expansion valve is used to control the throttling flow of outdoor heat
exchanger in heat mode.
 The slave electronic expansion valve or the sub-cooler electronic expansion valve is
used to the control the throttling evaporation flow of the gas side of sub-cooler.
 The outdoor throttling solenoid valve: It is used for outdoor unit condenser. When it is
necessary to control flow, it will cut off the 1-way valve that is in parallel with EXV1.
 Solenoid valve (inlet 1): Inlet 1 solenoid valve of refrigerant regulator
 Solenoid valve (inlet 2): Inlet 2 solenoid valve of refrigerant regulator
 Solenoid valve (top discharge): Gas outlet solenoid valve of refrigerant regulator
 Solenoid valve (bottom discharge): Oil outlet solenoid valve of refrigerant regulator
 Gas bypass valve: Open once energized to realize hot gas bypass
 Pressure balance valve: It is used to reduce difference between high pressure and low
pressure
 Output of compressor capacity is based on the capacity calculated by outdoor unit and
will be sent to drive control. Drive control will output the actual compressor frequency
according to the received frequency.
 Output of fan frequency is adjusted according to different mode, pressure and capacity.

Drive Control System

A. Filter Board: One of its purposes is to filter power interference when unit is under poor
power quality condition. The other purpose is to prevent unit from interfering other electrical
appliances, such as television. Because of the working mode of inverter, unit is sensitive to power
interference and therefore filter board is needed. This unit adopts 3-phase power supply, so the
filter board is a 3-phase filter board, whose input terminals are AC-L1, AC-L2, AC-L3 and N. The
corresponding output terminals are L1-OUT, L2-OUT, L3-OUT and N-OUT.
B. Drive Board: It is a key element of the control system. It is used to receive signals from
master control unit and transfer the 380V, 50Hz 3-phase power supply into alternate current
whose amplitude and frequency are adjustable and drives the compressor to work.
GMV5 Home DC Inverter Multi VRF Units
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