Gree GMV5E Series Service Manual page 267

GREE
avoiding blockage or loose welding. During welding, control pipe openings from being
over-heated.
② After the pipeline system is welded, use special supports and bolts to fix the compressors,
ensuring stability of the compressors during running.
③ Power lines of the compressors should be wired following the factory installation. You can refer to
the wiring diagram. Phase sequence error is not allowed.
Step 12: System check.
1. Check welding joints for abnormalities.
2. Charge nitrogen into the system for leakage detection. If you are maintaining ODUs and the IDU
system is normal, you can charge nitrogen into the ODU system only. Note that nitrogen should
be charged from both the high pressure side and low pressure side. You are advised to charge
through all valves. Nitrogen pressure should be larger than 20 kgf. Then, charge soapsuds into
the system and check specially the weld joints for leakage.
3. Finally, charge nitrogen into the system again for pressure check. Close all valves and keep
system pressure up to 25 kgf for more than 12 hours. If the pressure remains unchanged, you
can extract all air. Otherwise, you should find the leakage points first.
While determining system pressure change, take temperature into consideration. For 1° C
temperature change, pressure will change by 0.01 MPa accordingly. Suppose that nitrogen pressure
reaches 2.5 MPa at 30° C, 12 hours later, temperature decreases to 25° C and pressure decreases to
2.43 MPa accordingly. The system is regarded qualified despite the pressure decrease.
Step 13: Fill lubricant.
When a compressor is replaced, we should clear all lubricant of the system and determine fill
amount by referring to the basic parameters of units.
For example:
For GMV-280WM/E-X unit, one compressor is replaced; we should draw out all lubricant of
separator and other accessories in the system; pipes have been charged with nitrogen for cleaning. So
there is a little of residual lubricant inside the system. You are advised to add 3.5L new lubricant into the
system (determined by referring to the basic parameters of units ).
Specific procedure is as follows:
① GMV5E series units use FVC68D or FV-68H lubricant. Make sure to confirm the trademark of the
lubricant first. Lubricant of other trademarks is not allowed.
② Open all valves and extract air for 30 minutes or longer.
③ Connect a rubber hose to the oil checking valve at one end. Open the container that holds
lubricant and pour lubricant into a measuring glass. If the glass is too small to hold the lubricant
of a required amount, measure the lubricant portion by portion. Record volume of each portion
and then put the other end of the rubber hose into the glass.
④ Keep on extracting air and open the oil checking valve. The lubricant will be pressed into the low
pressure side of units.
⑤ If the lubricant is added portion by portion, close the oil checking valve first and then measure
another portion of lubricant. In the course of repeated measuring and adding, keep the extraction
action.
GMV5E DC INVERTER VRF UNITS SERVICE MANUAL
263