Daikin VRV-WIII Installation Manual

Contents

13 English9-6 Air tight test and vacuum dryingThe units were checked for leaks by the manufacturer.Confirm that the valves are firmly closed before Air tight test or vac-uum drying.To prevent entry of any impurities and insure sufficient pressureresistance, always use the special tools dedicated for R410A.• Air tight test: Make sure to use nitrogen gas.(For the service port location, refer to the“Caution” label attached on the front panel[right] of the outside unit.)(Refer to figure)1. [Service precautions] Label2. EL. COMPO. BOX cover3. [Caution] LabelPressurize the liquid and gas pipes to4.0MPa (40bar) (do not pressurize morethan 4.0MPa (40bar)). If the pressure doesnot drop within 24 hours, the system passes the test. If the pres-sure drops, check where the nitrogen leaks from.• Vacuum drying: Use a vacuum pump which can evacuate to–100.7kPa (5Torr, –755mmHg).1. Evacuate the system from the liquid and gas pipes by using avacuum pump for more than 2 hours and bring the system to–100.7kPa or less. After keeping the system under that condi-tion for more than 1 hour, check if the vacuum gauge rises ornot. If it rises, the system may either contain moisture inside orhave leaks.2. Following should be executed if there is a possibility of mois-ture remaining inside the pipe (if piping work is carried out dur-ing the raining season or over a long period of time rainwatermay enter the pipe during work).After evacuating the system for 2 hours, pressurize the systemto 0.05MPa (vacuum break) with nitrogen gas and evacuatethe system again using the vacuum pump for 1 hour to–100.7kPa or less (vacuum drying). If the system cannot beevacuated to –100.7kPa within 2 hours, repeat the operation ofvacuum break and vacuum drying.Then, after leaving the system in vacuum for 1 hour, confirmthat the vacuum gauge does not rise.9-7 Pipe insulationAfter finishing the leak test and vacuum drying, the piping must beinsulated. Take into account the following points:• Make sure to insulate the connection piping both liquid-side andgas-side and refrigerant branch kits entirely.Not insulating them may cause leaking. (The gas piping can reachtemperatures of 120°C. Be sure the insulation used can withstandsuch temperatures.)• Reinforce the insulation on the refrigerant piping according to theinstallation environment. Condensation might form on the surfaceof the insulation.• If there is a possibility that condensation on the shutoff valve mightdrip down into the indoor unit through gaps in the insulation andpiping because the outside unit is located higher than the indoorunit, etc., this must be prevented by caulking the connections, etc.CautionBe sure to insulate connection piping, as touching them cancause burns.9-8 Checking of device and installation conditionsBe sure to check the followings.1. Make sure there is no faulty power wiring or loosing of a nut.See “8. FIELD WIRING”.2. Make sure there is no faulty transmission wiring or loosing of a nut.See “8. FIELD WIRING”.3. Make sure there is no faulty refrigerant piping.See “9.REFRIGERANT PIPING”.4. Make sure piping size is correct.See “9-1 Selection of piping material”.5. Make sure insulation work is done.See “9-7 Pipe insulation”.6. Make sure insulation resistance of main power circuit is not dete-riorated.Using a megatester for 500V, check that the insulation resistanceof 2MΩ or more is attained by applying a voltage of 500V DCbetween power terminals and earth. Never use the megatester forthe transmission wiring (between outdoor and indoor unit, outdoorand COOL/HEAT selector and etc.).9-9 Additional refrigerant chargeCaution• Refrigerant cannot be charged until field wiring has been com-pleted.• Refrigerant may only be charged after performing the leak testand the vacuum drying.• When charging a system, care shall be taken that its maximumpermissible charge is never exceeded, in view of the danger of liq-uid hammer.• Charging with an unsuitable substance may cause explosionsand accidents, so always ensure that the appropriate refrigerant(R410A) is charged.• Refrigerant containers shall be opened slowly.• Always use protective gloves and protect your eyes when charg-ing refrigerant.• This outside unit is factory charged with refrigerant and depend-ing on pipe sizes and pipe lengths some systems require addi-tional charging of refrigerant.• Determine the amount of refrigerant to be added by referring to thetable, write it down on the included “Added Refrigerant” plate andattach it to the rear side of the front cover.Note: refer to the example of connection for the amount to be added.Additional refrigerant charge procedure (1)-normally• Charge the refrigerant to the liquid pipe in its liquid state. SinceR410A is a mixed refrigerant, its composition changes if chargedin a state of gas and normal system operation would no longer beassured.• Make sure to use installation tools you exclusively use on R410Ainstallations to withstand the pressure and to prevent foreignmaterials from mixing into the system.1. Before charging, check whether the tank has a siphon attached ornot.How to charge with a siphon attached tank.How to charge with other tank.2. After the vacuum drying is finished, charge the additional refriger-ant in its liquid state through the liquid shutoff valve service port.Taking into account following instructions:• Check that gas and liquid shutoff valves are closed.• Stop the compressor and charge the specified weight of refrig-erant.(If the outside unit is not in operation and the total amount cannotbe charged, follow the Additional refrigerant charge procedure (2)shown below.)Note• Procedures for charging additional refrigerant.(Refer to figure 24)1. Pressure reducing valve2. Nitrogen3. Refrigerant tank4. With a siphon5. Measuring instrument6. Vacuum pump7. Valve A8. Valve B9. Charge hose10. Outside unit11. Gas side12. Liquid side13. Discharge gas side14. Suction gas side15. Shutoff valve service port16. To indoor unit17. To indoor units / BS units18. Dotted lines represent onsite piping132There is a siphon tubeinside, so there is no needto turn the tank upside-down.Charge with the tank upright.Charge with the tank upside-down.