59
SERVICING
LOW SIDE
GAUGE
AND VALVE
HIGH SIDE
GAUGE
AND VALVE
Evacuation
3. If the vacuum pump is working properly, close the
valve to the vacuum thermocouple gauge and open
the high and low side valves to the high vacuum
manifold set. With the valve on the charging cylinder
closed, open the manifold valve to the cylinder.
4. Evacuate the system to at least 29 inches gauge
before opening valve to thermocouple vacuum gauge.
5. Continue to evacuate to a maximum of 250 microns.
Close valve to vacuum pump and watch rate of rise.
If vacuum does not rise above 1500 microns in three
to five minutes, system can be considered properly
evacuated.
6. If thermocouple vacuum gauge continues to rise and
levels off at about 5000 microns, moisture and non-
condensables are still present. If gauge continues to
rise a leak is present. Repair and re-evacuate.
7. Close valve to thermocouple vacuum gauge and
vacuum pump. Shut off pump and prepare to charge.
S-103 Charging
WARNING
REFRIGERANT UNDER PRESSURE!
* Do not overcharge system with refrigerant.
* Do not operate unit in a vacuum or at negative
pressure.
Failure to follow proper procedures may cause
property damage, personal injury or death.
Only use refrigerant certified to AHRI standards. Used
refrigerant may cause compressor damage. The
manufacturer is not responsible for damage or the
need for repairs resulting from the use of unapproved
refrigerant typesor used or recycled refrigerant. Most
portable machines cannot clean used refrigerant to
meet AHRI standards.
Charge the system with the exact amount of refrigerant.
Refer to the specification section or check the unit
nameplates for the correct refrigerant charge.
An inaccurately charged system will cause future
problems.
1. Using a quality set of charging scales, weigh the
proper amount of refrigerant for the system. Allow
liquid refrigerant only to enter the high side.
2. After the system will take all it will take, close the
valve on the high side of the charging manifold.
3. Start the system and charge the balance of the
refrigerant through the low side.
NOTE: R410A should be drawn out of the storage
container or drum in liquid form due to its fractionation
properties, but should be “Flashed” to its gas state before
entering the system. There are commercially available
restriction devices that fit into the system charging hose
set to accomplish this. DO NOT charge liquid R410A into
the compressor.
4. With the system still running, close the valve on the
charging cylinder. At this time, you may still have
some liquid refrigerant in the charging cylinder hose
and will definitely have liquid in the liquid hose.
Reseat the liquid line core. Slowly open the high side
manifold valve and transfer the liquid refrigerant from
the liquid line hose and charging cylinder hose into
the suction service valve port. CAREFUL: Watch so
that liquid refrigerant does not enter the compressor.
Final Charge Adjustment
The outdoor temperature must be 60°F or higher. Set the
room thermostat to COOL, fan switch to AUTO, and set the
temperature control well below room temperature.
After system has stabilized per startup instructions,
compare the operating pressures to the numbers listed
in the spec sheet manual. If pressures and amp draw are
too low, add charge. If pressures and amp draw are too
high, remove charge. Check subcooling and superheat as
detailed in the following section.
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