R410A DC Inverter Multi-split Technical Manual
Installation
59
GD Chigo Heating & Ventilation Equipment Co., Ltd.
3. Vacuum Dry and Leakage Checking
3.1 Air purging
Air and moisture in the refrigerant system have undesirable effects as indicatedbelow:
● Pressure in the system rises.
● Operating current rises.
● Cooling or heating efficiency drops.
● Moisture in the refrigerant circuit may freeze and block capillary tubing.
● Water may lead to corrosion of parts in the refrigeration system.
Therefore, the indoor unit and tubing between the indoor and outdoor unit mustbe leak tested and evacuated
to remove any non-condensables and moisturefrom the system.
3.1.1Air purging with vacuum pump
● Preparation
Check that each tube(both liquid and gas side tubes) between
the indoor andoutdoor units have been properly connected
and all wiring for the test run has been completed. Remove the
service valve caps from both the gas and the liquidside on the
outdoor unit. Note that both theliquid and the gasside service
valves on the outdoor unit arekept closed at this stage.
● When relocate the unit to another place,perform evacuation
using vacuum pump.
● Make sure the refrigerant added into the airconditioner
is liquid form in any case.
Caution in handling the packed valve
● Open the valve stem until it hits against thestopper. Do not try to
open it further.
● Securely tighten the valve stem cap with aspanneror the like.
● Valve stem cap tightening torque (SeeTightening torque table in
previous page ).
3.1 .2 When Using the Vacuum Pump
● Preparation
(For method of using a manifold valve, refer to its operation manual.)
1.Completely tighten the flare nuts, A, B, C, D, connect the manifold
Valvecharge hose to a charge port of the low-pressure valve on the
gas pipe side.
2. Connect the charge hose connection to the vacuum pump.
3. Fully open the handle Lo of the manifold valve.
4. Operate the vacuum pump to evacuate. After starting evacuation,
Slightlyloose the flare nut of the Lo valve on the gas pipe side and
check that the air isentering(Operation noise of the vacuum pump
changes and a compoundmeter indicates 0 instead of minus)
5 after the evacuation is complete, fully closethe handle Lo of the
manifold valve and stopthe operation of the vacuum pump. Makeevacuation for 15 minutes or more and
checkthat the compound meter indicates-76cmHg (-1x105Pa).
