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SERVICING
5. If pressure rises above 2000 microns, a leak is
present. Check for leaks and repair. Repeat the
evacuation procedure.
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
1
2
Triple Evacuation Method (Alternate)
1. Evacuate the system to 4000 microns and hold for 15
minutes. Break the vacuum with dry nitrogen, bring
the system pressure to 2-3 PSIG, and hold for 20
minutes. Release the nitrogen,
2. Evacuate to 1500 microns and hold for 20 minutes.
Break the vacuum with dry nitrogen again, bring the
system pressure back to 2-3 PSIG, and hold for 20
minutes.
3. Evacuate the system to 500 microns and hold for 60
minutes.
4. If the pressure rises to 1000 microns or less and
remains steady the system is considered leak free;
proceed to start-up.
Charging
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 types or used or recycled refrigerant. Most
portable machines cannot clean used refrigerant to meet
AHRI standards.
LEAK(S)
PRESENT
CONDENSIBLES OR SMALL
LEAK PRESENT
NO LEAKS
NO CONDENSIBLES
3
4
5
6
7
8
9
10
MINUTES
WARNING
CAUTION
Operating the compressor with the suction valve closed will
cause serious compressor damage.
Charge the system with the exact amount of refrigerant.
See the unit nameplate for the correct refrigerant charge
amount.
An inaccurately charged system will cause future
problems.
1. Using a charging scale, weigh in the refrigerant
charge amount listed on unit nameplate. 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.
Due to their design, Scroll compressors are inherently more
tolerant of liquid refrigerant.
Refrigerant Charge Check
(Units with Fixed Orifice Devices)
After completing airflow measurements and adjustments
the unit's refrigerant charge must be checked. All package
units with fixed orifice devices are charged using the super
heat method at the compressor suction line.
After superheat is adjusted it is recommended to check unit
subcooling at the condenser coil liquid line out.
CAUTION
25
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