Installation Guide

VACUUM TESTING
Step 10
Leaking Test
Leak test each indoor unit, one unit at a time. Repeat the leak test sequence for each indoor unit.
1. Connect the charging hose of the manifold valve to charge the end of the low-pressure valve.
2. Add dry nitrogen to a pressure of 200 lbs. Tightly close both high- and low-pressure valves.
3. Leak-test flare fittings with soap bubbles. If no leak is detected, release nitrogen.
Step 11
System Vacuum and Charge
Evacuate each indoor unit, one unit at a time. Repeat the evacuation sequence for each indoor unit.
UNIT DAMAGE HAZARD
Never use the system compressor as a vacuum pump. It may result in equipment damage
or improper system operation.
Refrigerant pipes 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.
NOTE: Always break a vacuum with dry nitrogen.
Using Vacuum Pump
1. Completely tighten flare nuts A, B, C, D,
connect manifold gauge charge hose to a
charge port of the low side service valve.
2. Connect charge hose to vacuum pump.
3. Fully open the low side of manifold gauge.
See figure at right.
4. Start vacuum pump.
5. Evacuate using either deep vacuum or triple evacuation method.
6. After evacuation is complete, fully close the low side of manifold gauge and stop
operation of vacuum pump.
7. The factory charge contained in the outdoor unit is good for up to 25 ft. (8 m) of line length.
NOTE: For refrigerant lines longer than 25 ft (8 m), add add’l refrigerant per foot of extra
piping up to the maximum allowable length. See System Requirement section on page 4
for more info.
8. Disconnect charge hose from charge connection of the low side service valve.
9. Fully open service valves B and A.
10. Securely tighten caps of service valves.
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Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling a vacuum of 500 microns
and a vacuum gauge 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.
VACUUM TESTING
CAUTION
Manifold Gauge
Deep Vacuum Graph
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5000
4500
4000
3500
3000
2500
2000
1500
1000
500
Leak in
System
Vacuum Tight
too Wet
Outdoor Unit
Service Valve
500 microns
Low Side Valve
High Side Valve
Charge Hose
Vacuum Pump
Low Side Valve
Charge Hose
Refrigerant
Indoor Unit
Low Side
High Side
Tight Dry
System
TWD-0813-017 Multi install rev:Layout 1 9/27/13 12:53 PM Page 25