VRV is a trademark of Daikin AC and stands for Variable Refrigerant Volume. Uses a combination of variable speed compressors and fans and electronic refrigerant valves to control the flow of refrigerant to multiple evaporators from one condenser. There are many major engineering differences from one series to the next.
A lot of info on VRV2 and VRV3 - including service manuals and engineering literature - is available from the website at *.*/commercial/docs ... **