KeepRite DLFCAB - System Evacuation and Charging Procedures; Deep Vacuum Method; Triple Evacuation Method; Final Tubing Check

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Specifications subject to change without notice.
SYSTEM EVACUATION AND
CHARGING
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
!
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.
System Vacuum and Charge
Using Vacuum Pump
1. Completely tighten flare nuts A, B, C, D, connect the manifold
gage charge hose to a charge port of the low side service valve
(see Fig. 54).
2. Connect the charge hose to the vacuum pump.
3. Fully open the low side of the manifold gage (see Fig. 55).
4. Start the vacuum pump.
5. Evacuate using either the deep vacuum or triple evacuation
method.
6. After the 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 as specified in the
ADDITIONAL REFRIGERANT CHARGE TABLE (see Table
NO TAG).
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 valves caps.
Outdoor Unit
Indoor Uni
t
Refrigerant
Service Valve
Low Side
High Side
A
B
C
D
Fig. 54 - Service Valve
Manifold Gage
500 microns
Low side valve
High side valve
Charge hose
Charge hose
Vacuum pump
Low side valve
Fig. 55 - Manifold
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 best way to
ensure a system is free of air and liquid water (see Fig. 56).
500
MINUTES
01234567
1000
1500
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
Fig. 56 - Deep Vacuum Graph
Triple Evacuation Method
The triple evacuation process should be used in accordance with Fig.
57. Refer to Fig. 57 and proceed as follows:
1. Pump system down to 500 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 nitrogen cylinder and regulator to the system and
open until the system pressure is 2 psig.
4. Close the service valve and allow the system to stand for 1 hr.
During this time, dry nitrogen will be able to diffuse throughout
the system absorbing moisture.
5. Repeat this procedure as indicated in Fig. 57. The system is
freed of any contaminants and water vapor.
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
EVACUATE
BREAK VACUUM WITH DRY NITROGEN
WAIT
EVACUATE
RELEASE CHARGE INTO SYSTEM
BREAK VACUUM WITH DRY NITROGEN
EVACUATE
WAIT
Fig. 57 - Triple Evacuation Method
Final Tubing Check
IMPORTANT: Ensure the factory tubing on both the indoor and
outdoor units has not shifted during shipment. Ensure the tubes are
not rubbing against each other or any sheet metal. Pay close
attention to the feeder tubes. Ensure the wire ties on the feeder
tubes are secure and tight.