Hitachi RAS-2-HVNP - Page 67

3. Piping work and refrigerant charge
53
SMGB0079 rev.0 - 01/2013
3
C A U T I O N
• Cap the end of the pipe when pipe is to be inserted through a wall hole.
• Do not put pipes on the ground directly without a cap or vinyl tape at the end of the pipe.
• Ifpipinginstallationisnotcompleteduntilnextdayoroveralongerperiodoftime,brazeofftheendsofthe
pipingandchargewithoxygenfreenitrogenthroughaSchradervalvetypeaccessttingtopreventmoisture
andparticlecontamination.
• DonotuseinsulationmaterialthatcontainsNH3,asitcandamagecopperpipematerialandbecomeasource
offutureleakage.
• Insulatetheunionsandare-nutsatthepipingconnectionpartcompletely.
• Completelyinsulatebothrefrigerantgasand liquid piping betweentheindoorunitandtheoutdoor unit to
avoidadecreaseofperformance;ifnot,dewwilloccuronthepipingsurface.
• RefrigerantcircuitandWatercircuitmustbeperformedandinspectedbyalicensedtechnicianandmustcom-
plywithallrelevantEuropeanandnationalregulations.

Insulation
Attach the pipe insulation to each branch using vinyl tape. Attach also insulation to eld supplied pipes in order to prevent
the capacity decrease according to the ambient air conditions and dewing on the low pressure pipe surface.
1. Cap.
2. Field supplied insulation.
3. Do not make a gap.
N O T E
When polyethylene foam is applied, it is recommended the
usageofawallthicknessof10mmfortheliquidpipingand
15mmto20mforthegaspiping.
C A U T I O N
• Performtheinsulationworkafterthepipesurfacetemperaturedecreasestotheroomtemperature,ifnotthe
insulationmaterialmaymelt.
• Iftheendsofthepipingsystemareopenafterendingthepipingwork,attachcapsorvinylbagssecurelyto
theendsofthepiping,avoidingmoistureanddustentering.