Installation Manual

Manuf
acturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
22
SYSTEM VACUUM AND CHARGE
Refrigerant pipes and indoor unit coils should be evacuated using the
recommended 500 microns deep vacuum method. The alternate triple
evacuation method may be used if the following procedure is followed.
NOTE: Always break a vacuum with dry nitrogen.
Using a Vacuum Pump
1. Completely tighten flare nuts A, B, C, D and connect the manifold gage
charge hose to a charge port of the low side service valve (see Fig. 34).
2. Connect the charge hose to vacuum pump.
3. Fully open the low side of manifold gage (see Fig. 35).
4. Start the vacuum pump.
5. Evacuate using either the deep vacuum or triple evacuation method.
6. After evacuation is complete, fully close the low side of manifold gage
and stop the vacuum pump operation.
7. The factory charge contained in the outdoor unit is good for up to 25 ft.
(8 m) of line length. For refrigerant lines longer than 25 ft. (8 m), add
refrigerant, up to the allowable length, as specified in the System
Requirements section.
8. Disconnect the charge hose from the charge connection of the low side
service valve.
9. Fully open service valves B and A.
10. Securely tighten the service valve caps.
Fig. 34 — Service Valve
Fig. 35 — Manifold Gauge
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 (see Fig.
36).
Fig. 36 — Deep Vacuum Graph
Triple Evacuation Method
The triple evacuation is the recommended method of dehydration.
Refer to Fig. 37 and proceed as follows:
1. Pump the system down to 1500 microns and allow the pump to
continue operating for an additional 15 minutes.
2. Close the service valves and shut off the vacuum pump.
3. Connect a dry nitrogen cylinder and regulator to the system and break
vacuum until the system reaches 2 psig.
4. Close the service valve and allow the system to stand for 1 hr. During
this time, the dry nitrogen can diffuse throughout the system absorbing
moisture.
5. Pump the system down to 1000 microns.
6. Break the vacuum with dry nitrogen (2 psig).
7. Pump the system down to 500 microns.
8. Perform the hold test for 30 minutes.
Fig. 37 — Triple Evacuation Method
Final Tubing Check
IMPORTANT: Ensure the factory tubing on both the indoor and
outdoor unit has not shifted during shipment. Ensure tubes are not
rubbing against each other or any sheet metal. Pay close attention to
feeder tubes, making sure wire ties on the feeder tubes are secure and
tight.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Never use the system compressor as a vacuum pump.
CAUTION
Outdoor Unit
Indoor Uni
t
Refrigerant
Service Valve
Liquid Side
Gas Side
Manifold Gage
500 microns
Low side valve
High side valve
Charge hose
Charge hose
Vacuum
pump
Low side valve
500
MINUTES
01234567
1000
1500
LEAK IN
SYSTEM
VACUUM
TIGHT
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
EVACUATE TO 1500 MICRONS
EVACUATE TO 500 MICRONS MINIMUM (HOLD FOR 30 MINUTES)
RE
LEASE CHARGE INTO SYSTEM BY OPENING VALVES COMPLETELY
BREAK VACUUM WITH DRY NITROGEN TO 2 PSIG
EVACUATE TO 1000 MICRONS
BREAK VACUUM WITH DRY NITROGEN TO 2 PSIG