Air Removal - Gree A Series Service Manual

(2)Recharge refrigerant
Excessive or deficient refrigerant may cause abnormal operation, malfunction or damage
to a compressor, so charge volume must comply with the requirements on the unit name-
plate which have been decided in strict tests; The figure may serve as a reference; a
charge process is as follows (one system as an example):
Step 1: Place a refrigerant container on an electronic scale and connect the container and
the pressure gauges by a flexible tube;
Step 2: Remove gases inside the flexible tube—half turning the shut-off valve of the con-
tainer, loosen the joint device between the flexible tube and pressure gauge; tighten the
joint device when a sound is sent out for 5s;
Step 3: Power up and down the electronic scale to enable it to reset;
Step 4: Ensure that the flexible tube has been evacuated and the scale reset, turn on all
valves connecting refrigerant containers and the unit; charge refrigerant required by the
nameplate to prevent oil dilution caused by excessive charging, and inhibit a capacity de-
cline of the unit induced by insufficient charging; when the unit is running, make sure it is
gaseous refrigerant (as possible as it can be) from a refrigerant container (that cannot be
turned upside down) that is injected into fluorine nozzles on intake lines; when the unit
powered down, be sure to charge refrigerant the fluorine nozzle at the high-pressure side
(if there is no nozzle at the high-pressure side, low-pressure side is an alternative.) in case
of liquid slug.
7.5.2

Air Removal

When there is air trapped in the system, expel them before charging refrigerant. The whole
system must be vacuumed as per steps stated below.
(1)Connect pipes for vacuuming at both the low and high pressure sides;
(2)Start the vacuum pump for vacuuming;
(3)When it reaches the targeted vacuum degree, charge refrigerant into the system. See the
nameplate for type and charging mount of refrigerant. Do charging from the low pressure
side. A manifold gauge should be connected to both the low and high pressure sides;
A Series Modular-type Air-cooled (Heat Pump) Chiller
Fig 7-2 Charging process
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