Carrier 42QHG009D8S - Air Evacuation; Evacuation Instructions

Safety Precautions
Air Evacuation
Air Evacuation
Preparations and Precautions
Air and foreign matter in the refrigerant
circuit can cause abnormal rises in pressure,
which can damage the air conditioner,
reduce its efciency, and cause injury. Use
a vacuum pump and manifold gauge to
evacuate the refrigerant circuit, removing any
non-condensable gas and moisture from the
system.
Evacuation should be performed upon initial
installation and when unit is relocated.
BEFORE PERFORMING EVACUATION
Check to make sure the connective
pipes between the indoor and outdoor
units are connected properly.
Check to make sure all wiring is
connected properly.
Evacuation Instructions
1. Connect the charge hose of the manifold
gauge to service port on the outdoor
unit’s low pressure valve.
2. Connect another charge hose from the
manifold gauge to the vacuum pump.
3. Open the Low Pressure side of the
manifold gauge. Keep the High Pressure
side 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 (-10
5
Pa).
Manifold Gauge
Compound gauge
-76cmHg
Low pressure valve
Pressure hose/
High pressure valve
Charge hose
Vacuum pump
Charge hose
Low pressure valve
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 change in system pressure.
8. If there is a change in system pressure,
refer to Gas Leak Check section for
information on how to check for leaks. If
there is no change in system pressure,
unscrew the cap from the packed valve
(high pressure valve).
9. Insert hexagonal wrench into the packed
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 one
minute to make sure that there is no
change in pressure. The Pressure
Gauge should read slightly higher than
atmospheric pressure.
11. Remove the charge hose from the
service port.
Flare nut
valve stem
valve body
Cap
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. You may 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.
Page 19-GB