20
Manifold Gage
500 microns
Low side valve
High side valve
Charge hose
Charge hose
Vacuumpump
Low side valve
A07361
Fig.29 -- Manifold
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capableof
pulling a vacuum of 500 micro ns and a vacuum gage capable of
accurately measuring this vacuum depth. Th ed eep vacuum method
is the most positive way of assuring a system is free of air and
liquidwater. (SeeFig. 30)
500
MINUTES
01234567
1000
1500
LEAKI N
SYSTEM
VACUUMTIGHT
TOO WET
TIGHT
DRYSYSTEM
2000
MICRONS
2500
3000
3500
4000
4500
5000
A95424
Fig.30 -- Deep VacuumGraph
TripleEvacuationMethod
The tripleevacuation method should only be used when vacuum
pump is only capable ofpumping down to 28 in. of mercury
vacuumand system does not containany liquid water.
Refer to Fig. 31 and proceed as follows:
1. Pump systemdown to 28 in. of mercury and allowpump to
continueoperating for anadditional 15 minutes.
2. Close servicevalves and shut off vacuum pump.
3. Connect a nitrogencylinder and regulator to systemand
open until system pressure is 2 psig.
4. Close servicevalve and allow system to standfor 1 hr.Dur-
ingthis time, dry nitrogenwill be ableto diffuse throughout
thesystem absorbing moisture.
5. Repeat thisprocedure as indicated in Fig. 31. System will
then be free of any contaminants and water vapor.
CHECKFOR TIGHT,DRY SYSTEM
(IFIT HOLDS DEEP VACUUM)
EVACUATE
BREAKVACUUM WITH DRY NITROGEN
WAIT
EVACUATE
RELEASECHARGE INTO SYSTEM
BREAKVACUUM WITH DRY NITROGEN
EVACUATE
WAIT
A95425
Fig.31 --TripleEvacuation Method
ToStart the Unit:1. If the outdoor unit is equipped with a crankcaseheater, turn
on the indoor and outdoordisconnect switches to supply
powerthe system 12 hours before startingthe system.
2. Releasecharge into the system by opening (back--seating)
liquid and suction line service valves.
3. Set the wirelessremote control or wired remotecontrol be-
lowambient temperature.Operate the unit for 15 minutes.
4. Refer to Table5 to determine if additional chargeis re-
quired.Also, if you have a long line application,refer tothe
Duct Free Long Line ApplicationGuide to determine the
additionalcharge thatis required beyond 25 ft(7.6 m).
5. Calculatethe total additional chargerequired and weigh in.
6. Charge shouldbe added as liquid (not gas)slowly and care-
fullyto low side to avoid liquidslugging.
40QAC/38HDR -- 40QAQ/38QR
R