Hitachi RAS-5.0UFESMH1 - Hitachi Air Conditioner Troubleshooting and Fault Codes; Troubleshooting Normal Malfunctions; Troubleshooting by Fault Codes Overview

4 Piping connection
1. Conrmthatthevalveisclosed
2. Connecttheindoorunitandtheoutdoorunitwitheld-supplied
refrigerant piping. Suspend the refrigerant piping at certain points
andpreventtherefrigerantpipingfromtouchingtheweakpartofthe
building such as wall, ceiling, etc.
(Iftouched,abnormalsoundmayoccurduetothevibrationofthe
piping.Payspecialattentionincaseofshortpipinglength.)
3. Tightenthearenutwithtwospannersasshownintherightgure.
4. Applytherefrigerantoil(eld-supplied)thinlyattheseatsurfaceof
thearenutandpipebeforeconnectingandtightening.Andwhen
tighteningthearenut,usetwospanners.
5. Outdoor refrigerant piping should connect with stop valve.
Doublespannerwork
Tube size Torque(Nm)
∅6.35mm 20
∅9.52mm 40
∅12.7mm 60
∅15.88mm 80
∅19.05mm 100
Tighteningtorqueforarenut
6. Afternishingconnectingtherefrigerantpipes,keepitwarmwiththe
insulationmaterialasshownintherightgure.
For outdoor unit side, surely insulate every piping including valves.
Cover piping joints with pipe cover.
Using piping tape, apply taping starting from the entry of outdoor unit.
Fixtheendofpipingtapewithadhesivetape.
When piping has to be arranged through above ceiling, closet or
area where temperature and humidity are high, use wind additional
commercially sold insulation for prevention of condensation
Clamp
(eld-supplied)
Insulation
(eld-supplied)
Refrigerant pipe
(eld-supplied)
Insulation
(eld-supplied)
Piping insulation procedure
5 Air tight test
Do use Nitrogen
Connect the gauge manifold using charging hoses with a nitrogen cylinder
tocheckjointsoftheliquidlineandthegaslinestopvalves.
Perform the air tight test.
Don't open the gas line stop valves.
Applynitrogengaspressureof4.15MPa.
Checkanygasleakageatarenutconnections,orbrazedpartsbygasleak
detector or foaming agent.
Gas pressure doesn’t decrease, which is OK.
After the air tight test, release nitrogen gas.
Procedure
Completion
of
Refrigerant
piping
Applying
nitrogen
gas
Air tight procedure
Checkof
pressure
decrease
Pass
Repairing
ofleakage
part
INSTALLATIONINSTRUCTIONS
HO2019292HA
14