Mitsubishi PUZ-A18NHA6 - Refrigerant Collecting Procedure; Refrigerant Pipe Airtight Testing; Test Run Procedures

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3. Start and finish of test run
• Operationfromtheindoorunit
 Executethetestrunusingtheinstallationmanualfortheindoorunit.
• Operationfromtheoutdoorunit
 ByusingtheDIPswitchSW4onthecontrolboardofoutdoorunit,testruncanbestartedandfinished,andits
operationmode(cooling/heating)canbesetup.
1Settheoperationmode(cooling/heating)usingSW4-2.
2TurnonSW4-1tostarttestrunwiththeoperationmodesetbySW4-2.
3TurnoffSW4-1tofinishthetestrun.
• Theremaybeafaintknockingsoundaroundthemachineroomafterpowerissupplied,butthisisnota
problemwiththeproductbecausethelinearexpansionvalveisjustmovingtoadjustopeningpulse.
• Theremaybeaknockingsoundaroundthemachineroomforseveralsecondsaftercompressorstarts
operating.Butthisisnotaproblemwithproductbecausethecheckvalveitselfgeneratesthesoundbecause
pressuredifferenceissmallintherefrigerantcircuit.
Note:
The operation mode cannot be changed by SW4-2 during test run. (To change test run mode, stop the unit by SW4-1, change the
operation mode and restart the test run by SW4-1.)
OFF
1 2
ON
<SW4>
A B
C D
A Stop C Operation
B Cooling D Heating
(PUZ only)
2. Refrigerant pipe airtight testing method
(1)Connectthetestingtools.
 •MakesurethestopvalvesABareclosedanddonotopenthem.
 •AddpressuretotherefrigerantlinesthroughtheserviceportCoftheliquidstopvalveD.
(2)Donotaddpressuretothespecifiedpressureallatonce;addpressurelittlebylittle.
 1Pressurizeto0.5MPa(5kgf/cm²G),wait5minutes,andmakesurethepressuredoesnotdecrease.
 2Pressurizeto1.5MPa(15kgf/cm²G),wait5minutes,andmakesurethepressuredoesnotdecrease.
 3Pressurizeto4.15MPa(41.5kgf/cm²G)andmeasurethesurroundingtemperatureandrefrigerantpressure.
(3) Ifthespecifiedpressureholdsforaboutonedayanddoesnotdecrease,thepipeshavepassedthetestandtherearenoleaks.
 • Ifthesurroundingtemperaturechangesby1°C,thepressurewillchangebyabout0.03MPa(0.3kgf/cm²G).Makethenecessarycorrections.
(4)Ifthepressuredecreasesinsteps(2)or(3),thereisagasleak.Lookforthesourceofthegasleak.
A
Stop valve <Liquid side>
B Stop valve <Gas side>
C Service port
D Open/Close section
A
B
H
I
C
D
E
F
G
D
B
A
C
E
Local pipe
F
Sealed, same way for gas side
G
Pipe cover
H
Do not use a wrench here.
Refrigerant leakage may result.
I
Use 2 wrenches here.
1. Refrigerant collecting (pump down)
Performthefollowingprocedurestocollecttherefrigerantwhenmovingtheindoorunitortheoutdoorunit.
1Supplypower(circuitbreaker).
•Whenpowerissupplied,makesurethat“CENTRALLYCONTROLLED”isnotdisplayedontheremotecontroller.If“CENTRALLY
CONTROLLED”isdisplayed,therefrigerantcollecting(pumpdown)cannotbecompletednormally.
•Start-upoftheindoor-outdoorcommunicationtakesabout3minutesafterthepower(circuitbreaker)isturnedon.Startthepump-down
operation3to4minutesafterthepower(circuitbreaker)isturnedON.
2Aftertheliquidstopvalveisclosed,setSW1-1onthecontrolboardoftheoutdoorunittoON.Thecompressor(outdoorunit)andventilators
(indoorandoutdoorunits)startoperatingandrefrigerantcollectingoperationbegins.LED1andLED2onthecontrolboardoftheoutdoor
unitarelit.
•OnlysetSW1-1toONiftheunitisstopped.However,eveniftheunitisstoppedandSW1-1issettoONlessthanthreeminutesafterthe
compressorstops,therefrigerantcollectingoperationcannotbeperformed.Waituntilcompressorhasbeenstoppedforthreeminutesand
thensetSW1-1toONagain.
3Becausetheunitautomaticallystopsinabouttwotothreeminuteswhentherefrigerantcollectingoperationiscompleted(LED1off,LED2
lit),besuretoquicklyclosethegasstopvalve.IfLED1islitandLED2isoffandtheoutdoorunitisstopped,refrigerantcollectionisnot
properlyperformed.Opentheliquidstopvalvecompletely,andthenrepeatstep2afterthreeminuteshavepassed.
•Iftherefrigerantcollectingoperationhasbeencompletednormally(LED1off,LED2lit),theunitwillremainstoppeduntilthepowersupply
isturnedoff.
4Turnoffthepowersupply(circuitbreaker).
•Notethatwhentheextensionpipingisverylongwithlargerefrigerantamount,itmaynotbepossibletoperformapump-downoperation.
Warning:
When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes. The compressor may burst if
air etc. get into it.
OCH577A