C. REFRIGERANT TUBING
Connect vapor tube to fitting on outdoor unit vapor service valves. Connect liquid tube to filter drier. (See Fig. 6 and Table 1.) Use refrigerant grade tubing.
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CONNECTOR
TUBE
A95509
Fig. 6—Liquid-Line Filter Drier
D. SWEAT CONNECTION
CAUTION: To avoid valve damage while brazing, ser- vice valves must be wrapped in a
Use refrigerant grade tubing. Service valves are closed from factory and ready for brazing. After wrapping service valve with a wet cloth, braze sweat connections using industry accepted meth- ods and materials. Consult local code requirements. Refrigerant tubing and indoor coil are now ready for leak testing. This check should include all field and factory joints.
E.EVACUATE REFRIGERANT TUBING AND INDOOR COIL
CAUTION: To avoid compressor damage, never use the system compressor as a vacuum pump.
Refrigerant tubes and indoor coil should be evacuated using the recommended deep vacuum method of 500 microns. The alternate triple evacuation method may be used if the procedure outlined below is followed. Always break a vacuum with dry nitrogen.
DEEP VACUUM METHOD
The deep vacuum method requires a vacuum pump capable of pulling a vacuum of 500 microns and a vacuum gage capable of accurately measuring this vacuum depth. The deep vacuum method is the most positive way of assuring a system is free of air and liquid water. (See Fig. 7.)
TRIPLE EVACUATION METHOD
The triple evacuation method should only be used when vacuum pump is only capable of pumping down to 28 in. of mercury vacuum and system does not contain any liquid water. Refer to Fig. 8 and proceed is as follows:
1.Pump system down to 28 in. of mercury and allow pump to continue operating for an additional 15 minutes.
2.Close service valves and shut off vacuum pump.
3.Connect a dry nitrogen cylinder and regulator to system and open until system pressure is 2 psig.
4.Close service valve and allow system to stand for 1 hr. During this time, dry nitrogen will be able to diffuse throughout the system absorbing moisture.
5000 |
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4500 |
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4000 |
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3500 |
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3000 |
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2500 |
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MICRONS2000 |
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1500 |
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1000 |
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500 |
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0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
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Fig. 7—Deep Vacuum Graph
5.Repeat this procedure as indicated in Fig. 8. System will then be free of any contaminants and water vapor.
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
CHECK FOR TIGHT, DRY SYSTEM (IF IT HOLDS DEEP VACUUM)
CHARGE SYSTEM
A95425
Fig. 8—Triple Evacuation Method
VIII. MAKE ELECTRICAL CONNECTIONS
WARNING: To avoid personal injury or death, do not supply power to unit with compressor terminal box cover removed.
Be sure field wiring complies with local and national fire, safety, and electrical codes, and voltage to system is within limits shown on unit rating plate. Contact local power company for correction of improper voltage. See unit rating plate for recommended circuit protection device.
NOTE: Operation of unit on improper line voltage constitutes abuse and could affect unit reliability. See unit rating plate. Do not install unit in system where voltage may fluctuate above or below permissible limits.
NOTE: Use copper wire only between disconnect switch and unit.
NOTE: Install branch circuit disconnect of adequate size per NEC to handle unit starting current. Locate disconnect within sight from and readily accessible from unit, per Section