
- ii -
• Donotusetheexistingrefrigerantpiping.
- The old refrigerant and refrigerant oil in the existing
piping contains a large amount of chlorine which
may cause the refrigerant oil of the new unit to dete-
riorate.
- R410A is a high-pressure refrigerant and can cause
the existing piping to burst.
• UserefrigerantpipingmadeofC1220(CU-DHP)
phosphorusdeoxidizedcopperasspeciedinthe
JISH3300“Copperandcopperalloyseamless
pipesandtubes”.Inaddition,besurethatthein-
nerandoutersurfacesofthepipesarecleanand
freeofhazardoussulphur,oxides,dust/dirt,shav-
ingparticles,oils,moisture,oranyothercontami-
nant.
- Contaminants on the inside of the refrigerant piping
may cause the refrigerant residual oil to deteriorate.
• Storethepipingtobeusedduringinstallation
indoorsandkeepbothendsofthepipingsealed
untiljustbeforebrazing.(Storeelbowsandother
jointsinaplasticbag.)
- If dust, dirt, or water enters the refrigerant cycle,
deterioration of the oil and compressor trouble may
result.
• Applyasmallamountofesteroil,etheroil,or
alkylbenzenetoares.(forindoorunit)
- Inltration of a large amount of mineral oil may
cause the refrigerant oil to deteriorate.
• Useliquidrefrigeranttollthesystem.
- If gas refrigerant is used to seal the system, the
composition of the refrigerant in the cylinder will
change and performance may drop.
• DonotusearefrigerantotherthanR410A.
- If another refrigerant (R22, etc.) is mixed with
R410A, the chlorine in the refrigerant may cause the
refrigerant oil to deteriorate.
• Useavacuumpumpwithareverseowcheck
valve.
- The vacuum pump oil may ow back into the refrig-
erant cycle and cause the refrigerant oil to deterio-
rate.
• Donotusethefollowingtoolsthatareusedwith
conventionalrefrigerants.
(Gaugemanifold,chargehose,gasleakdetector,
reverseowcheckvalve,refrigerantchargebase,
refrigerantrecoveryequipment)
- If the conventional refrigerant and refrigerant oil are
mixed in the R410A, the refrigerant may deterio-
rated.
- If water is mixed in the R410A, the refrigerant oil
may deteriorate.
- Since R410A does not contain any chlorine, gas
leak detectors for conventional refrigerants will not
react to it.
• Donotuseachargingcylinder.
- Using a charging cylinder may cause the refrigerant
to deteriorate.
• Donotuseantioxidantorleak-detectionadditive.
• Beespeciallycarefulwhenmanagingthetools.
- If dust, dirt, or water gets in the refrigerant cycle, the
refrigerant may deteriorate.
• Iftheairconditionerisinstalledinasmallroom,
measuresmustbetakentopreventtherefriger-
antconcentrationfromexceedingthesafetylimit
eveniftherefrigerantshouldleak.
- Consult the dealer regarding the appropriate meas-
ures to prevent the safety limit from being exceeded.
Should the refrigerant leak and cause the safety
limit to be exceeded, hazards due to lack of oxygen
in the room could result.
• Whenmovingandreinstallingtheairconditioner,
consultthedealeroranauthorizedtechnician.
- If the air conditioner is installed improperly, water
leakage, electric shock, or re may result.
• Aftercompletinginstallationwork,makesurethat
refrigerantgasisnotleaking.
- If the refrigerant gas leaks and is exposed to a fan
heater, stove, oven, or other heat source, it may gen-
erate noxious gases.
• Donotreconstructorchangethesettingsofthe
protectiondevices.
- If the pressure switch, thermal switch, or other
protection device is shorted and operated forcibly,
or parts other than those specied by Mitsubishi
Electric are used, re or explosion may result.
• Todisposeofthisproduct,consultyourdealer.
• Theinstallerandsystemspecialistshallsecure
safetyagainstleakageaccordingtolocalregula-
tionorstandards.
- Following standards may be applicable if local regu-
lation are not available.
• Payaspecialattentiontotheplace,suchasa
basement,etc.whererefrigerationgascanstay,
sincerefrigerationisheavierthantheair.