12 EnglishEvacuate the system from the liquid pipe, suction gas pipe, HP/LPgas pipe and equalizer pipe shutoff valve service ports by using avacuum pump for more than 2 hours and bring the system to–14.6 psi or less. After keeping the system under that condition formore than 1 hour, check if the vacuum gauge rises or not. If it rises,the system may either contain moisture inside or have leaks.NOTEIf moisture might enter the piping, follow belows.(I.e., if doing work during the rainy season, if the actual work takeslong enough that condensation may form on the inside of thepipes, if rain might enter the pipes during work, etc.)After evacuating the system for 2 hours, pressurize the system to 7.25psi (vacuum break) with nitrogen gas and evacuate the system againusing the vacuum pump for 1 hour to –14.6 psi or less (vacuum drying).If the system cannot be evacuated to –14.6 psi within 2 hours, repeatthe operation of vacuum break and vacuum drying.Then, after leaving the system in vacuum for 1 hour, confirm that thevacuum gauge does not rise.9. PIPE INSULATION• Insulation of pipes should be done after performing “8. AIR TIGHTTEST AND VACUUM DRYING”.• Always insulate the liquid piping, the HP/LP gas piping, the gas pip-ing, and these pipe connections.Failing to insulate the pipes may cause leaking or burns.Especially, be sure to insulate the HP/LP gas piping as withstandingas the suction pipe because the suction gas follows in the HP/LP gaspiping when the system is whole cooling mode.And be sure to use the insulation which can withstand such temper-atures of 248°F or more for the HP/LP gas piping, the equalizer pipeand the gas piping because the HP/LP gas follows in these pipings.• Reinforce the insulation on the refrigerant piping according to theinstallation environment. Condensation might form on the surface ofthe insulation. Refer to the below. Ambient temperature : 86°F, humidity : 75% to 80% RH : min.thickness : 9/16 in.. If the ambient temperature exceeds 86°F and the humidity 80%RH, then the min. thickness is 3/4 in..See the Engineering data book for detail.• If there is a possibility that condensation on the shutoff valve mightdrip down into the indoor unit through gaps in the insulation and pip-ing because the outside unit is located higher than the indoor unit,etc., this must be prevented by caulking the connections, etc.(Refer to figure 25)• The piping lead-out hole lid should be attached after opening aknock hole. (Refer to figure 26)• If small animals and the like might enter the unit through the pipinglead-out hole, close the hole with blocking material (procured on site)after completion of “11. ADDITIONAL REFRIGERANT CHARGEAND CHECK OPERATION”. (Refer to figure 29)(Refer to figure 25)1. Insulation material2. Caulking, etc.(Refer to figure 26)1. Piping lead-out hole lid2. Open a knock hole at “ ”.3. Block “ ”.NOTE• After knocking out the holes, we recommend you remove burrs in theknock holes (See figure 26) and paint the edges and areas aroundthe edges using the repair paint.10. CHECKING OF DEVICE AND INSTALLA-TION CONDITIONSBe sure to check the followings.For those doing electrical work1. Make sure there is no faulty transmission wiring or loosing of a nut.See “7-4 Transmission Wiring Connection Procedure”.2. Make sure there is no faulty power wiring or loosing of a nut.See “7-5 Power Wiring Connection Procedure”.3. Has the insulation of the main power circuit deteriorated?Measure the insulation and check the insulation is above regularvalue in accordance with relevant local and national regulations.For those doing pipe work1. Make sure piping size is correct.See “6-1 Selection of piping material and Refrigerant branching kit”.2. Make sure insulation work is done.See “9. PIPE INSULATION”.3. Make sure there is no faulty refrigerant piping.See “6. REFRIGERANT PIPING”.11. ADDITIONAL REFRIGERANT CHARGEAND CHECK OPERATIONThe outside unit is charged with refrigerant when shipped from the factory,but depending on the size and length of the piping when installed, it mayrequire additional charging.For charging the additional refrigerant, follow the procedure in this chapter.And then carry out the check operation.11-1 Before working[About the refrigerant tank]Check whether the tank has a siphon pipe before charging and placethe tank so that the refrigerant is charged in liquid form.(See the figure below.)NOTE• Always use the proper refrigerant (R410A). If charged with the refrig-erant containing an improper material, it may cause an explosion oraccident.• R410A is a mixed refrigerant, so charging it as a gas will cause the refrig-erant composition to change, which may prevent normal operation.[Shutoff valve operation procedure]When operating the shutoff valve, follow the procedure instructed below.NOTE• Do not open the shutoff valve until “10. CHECKING OF DEVICEAND INSTALLATION CONDITIONS” are completed. If the shutoffvalve is left open without turning on the power, it may cause refriger-ant to buildup in the compressor, leading insulation degradation.• Be sure to use the correct tools.The shutoff valve is not a back-seat type. If forced it to open, it mightbreak the valve body.• When using a service port, use the charge hose.• After tightening the cap, make sure no refrigerant gas is leaking.With siphon pipeOther tanksStand the tank upright and charge.(The siphon pipe goes all the way inside,so the tank does not need be putupside-down charge in liquid form.)Stand the tank upside-down and charge.
