Gree Ultra Heat GMV-V72W/A-F, Service Manual, Page: 18 / 240

Ultra Heat GMV VRF Technical Service Manual UNIT INTRODUCTION
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NOTICE! Contact local sales company for optional accessories.
6 BASIC REQUIREMENT FOR PIPE CONNECTION
1. Outdoor units adopt the modular combination design of individual cooling system, that is, units
are connected by using pipes in parallel during installation. The tubing system used among modules
includes liquid pipes and gas pipes.
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Functions of oil check valve: During after-sale maintenance, the oil check valve can be used to extract
lubricating oil samples, which are further detected to analyze the oil quality in the system. The oil check
valve can also serve as the inlet for lubricating oil charging. Before extracting lubricating oil from the
system, stop the system for at least 12 hours and release ref
rigerant. Do not extract oil until system’s
pressure drops to 0.05MPa (7.25psi) or below; otherwise, overheat oil may burn the operator.

Functions of low-pressure check valve: It is mainly used for low pressure detection of the system and
refrigerant charging during after-sale maintenance.
Pipe connection diagram of outdoor module: