SERVICE MANUAL
R
−
410A Ductless Split System: DLF4(A/H), DLC4(A/H)
421 08 9204 00
39
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
Completely tighten flare nuts A, B, C, D, connect manifold gage
charge hose to a charge port of the low side service valve.
(See Fig. 13.)
Connect charge hose to vacuum pump.
Fully open the low side of manifold gage. (See Fig. 14)
Start vacuum pump
Evacuate using either deep vacuum or triple evacuation method.
After evacuation is complete, fully close the low side of manifold
gage and stop operation of vacuum pump.
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 0.1 oz. per foot of extra piping up to the maximum
allowable length.
Disconnect charge hose from charge connection of the low side
service valve.
Fully open service valves B and A.
Securely tighten caps of service valves.
Outdoor Unit
Indoor Unit
Refrigerant
Service Valve
Low Side
High Side
A
B
C
D
A07360
Figure 12
-
Service Valve
Manifold Gage
500 microns
Low side valve
High side valve
Charge hose
Charge hose
Vacuum pump
Low side valve
A07361
Figure 13
-
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 most positive way of assuring a system is free of
air and liquid water. (See Fig. 15)
500
MINUTES
0
1
2
3
4
5
6
7
1000
1500
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
A95424
Figure 14
-
Deep Vacuum Graph
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. 16 and proceed as follows:
Pump system down to 28 in. of mercury and allow pump to con-
tinue operating for an additional 15 minutes.
Close service valves and shut off vacuum pump.
Connect a nitrogen cylinder and regulator to system and open
until system pressure is 2 psig.
Close service valve and allow system to stand for 1 hr. During
this time, dry nitrogen will be able to diffuse throughout the sys-
tem absorbing moisture.
Repeat this procedure as indicated in Fig. 16. System will then
be free 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
A95425
Figure 15
-
Triple Evacuation Method
Final Tubing Check
IMPORTANT
: Check to be certain factory tubing on both 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 feeder tubes
are secure and tight.
