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3.
Open the Low Pressure valve of the manifold
gauge. Keep the High Pressure valve closed.
4.
Turn on the vacuum pump to evacuate the
system.
5.
Run the vacuum for at least 15 minutes, or
until the Compound Meter reads -76cmHG
(-100 kPa or -30In Hg).
6.
Close the Low Pressure side of the manifold
gauge, and turn off the vacuum pump.
7.
Wait for 5 minutes, then check that there
has been no rise in the vacuum reading.
8.
If there is a rise in system vacuum, refer
to Gas Leak Check section for information
on how to check for leaks. If there is no
change in vacuum reading, unscrew the cap
from the service valve (high pressure valve).
9.
Insert hexagonal wrench into the service valve
(high pressure valve) and open the valve by
turning the wrench in a 1/4 counterclockwise
turn. Listen for gas to exit the system, then
close the valve after 5 seconds.
10.
Watch the Pressure Gauge for few minutes
to make sure that there is no drop in the
pressure. The Pressure Gauge should now
show higher than the atmospheric pressure.
Flare nut
Cap
Valve body
Valve stem
11.
Remove the charge hose from the service port.
12.
Using hexagonal wrench, fully open both the
high pressure and low pressure valves.
13.
Tighten valve caps on all three valves (service
port, high pressure, low pressure) by hand.
Then tighten it further using a torque
wrench if needed.
OPEN VALVE STEMS GENTLY
When opening valve stems, turn the hexagonal
wrench until it hits against the stopper. Do not
try to force the valve to open further.
Note on Adding Refrigerant
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Connective Pipe
Length (m)
Air Purging
Method
Additional Refrigerant
< Standard pipe length Vacuum Pump
N/A
> Standard pipe
length
Vacuum Pump
Liquid Side: Ø 6.35 (ø 1/4”)
Gas side either
Ø 9.52 (ø 3/8”) or
Ø 12.7 (ø 1/2”)
Add for lengths beyond 5m (16 feet)
(Per additional meter) x 15g /m
(Per additional feet) x 0.16 oZ/ft
CAUTION
DO NOT
mix refrigerant types. Assure to use only the same type of refrigerant (r410a).
Fig. 6.2
Air Evacuation
Some systems require additional charging depending on pipe lengths. The pipe length varies according
to locations of the indoor and outdoor units. The system has been factory charged with sufficient R410a
refrigerant for the standard pipe length of 5m (16‘). The additional refrigerant to be charged can be
calculated using the following formula. This is necessary only if the length exceeds 7.5m (25 feet).
Liquid Side: Ø 9.52 (ø 3/8”)
Gas side either
Ø 15.87 (ø 5/8”) or
Ø 19.05 (ø 3/4”)
Add for lengths beyond 5m (16 feet)
(Per additional feet) x 0.32 oZ/ft
(Per additional meter) x 30 g/m
