Toshiba MMW-AP0481CHQ-E Installation Manual

Also see for MMW-AP0481CHQ-E: Service manual Manual

– 19 –8 Refrigerant pipingCAUTIONWhen the refrigerant pipe is long,provide support brackets atintervals of 2.5 m to 3 m to clampthe refrigerant pipe. Otherwise,abnormal sound may begenerated.Use the flare nut attached withthe indoor unit or R410A flare nut. Permissible piping length andheight differenceThey vary depending on the outdoor unit. For details,refer to the Installation Manual attached to the outdoorunit, and this manual (Refer to "3. System control ofHot Water Module"). Pipe size Connecting refrigerant pipingFlaring1 Cut the pipe with a pipe cutter.Remove burrs completely. (Remaining burrs maycause gas leakage.)2 Insert a flare nut into the pipe, and flare thepipe.Use the flare nut provided with the unit or the oneused for the R410A refrigerant. The flaringdimensions for R410A are different from the onesused for the conventional R22 refrigerant. A newflare tool manufactured for use with the R410Arefrigerant is recommended, but the conventionaltool can still be used if the projection margin of thecopper pipe is adjusted to be as shown in thefollowing table.Projection margin in flaring: B (Unit: mm)Flaring diameter size: A (Unit: mm)* In case of flaring for R410A with the conventionalflare tool, pull it out approx. 0.5 mm more than thatfor R22 to adjust to the specified flare size. Thecopper pipe gauge is useful for adjusting projectionmargin size.• The sealed gas was sealed at the atmosphericpressure so when the flare nut is removed, there willno “whooshing” sound: This is normal and is notindicative of trouble.• Use two wrenches to connect the indoor unit pipe.Model MMW- Pipe size (mm)Gas side Liquid sideAP048 Ø15.9 Ø9.5Outer dia. ofcopper pipe R410A tool used Conventionaltool used6.4, 9.5 0 to 0.5 1.0 to 1.512.7, 15.9Outer dia. of copper pipe A +0–0.46.4 9.19.5 13.212.7 16.615.9 19.7Work using double spanner• Use the tightening torque levels as listed in the tablebelow.• Tightening torque of flare pipe connections.Pressure of R410A is higher than that of R22.(Approx. 1.6 times) Therefore, using a torquewrench, tighten the flare pipe connecting sectionswhich connect the indoor and outdoor units of thespecified tightening torque.Incorrect connections may cause not only a gas leak,but also a trouble of the refrigeration cycle.CAUTIONTightening with an excessivetorque may crack the nutdepending on installationconditions. Airtight test / air purge, etc.For air tightness test, adding refrigerant, refer to theInstallation Manual attached to the outdoor unit.CAUTION• Do not supply power to theindoor unit and the hot watermodule until the airtight test andvacuuming are completed. (Ifthe indoor unit or the hot watermodule is powered on, thepulse motor valve is fully closed,which extends the time forvacuuming.)• After the vacuuming iscompleted, carry out thefollowing procedure beforeadding refrigerant.Plate heat exchanger mayexplode because the water inthe plate heat exchangerfrozen.To avoid this phenomenon, addrefrigerant before carrying out awater supply to the water pipesystem of the Hot WaterModule. Open the valve fullyOpen the valve of the outdoor unit fully.Outer dia. of connectingpipe (mm) Tightening torque (N•m)6.4 14 to 18 (1.4 to 1.8 kgf•m)9.5 33 to 42 (3.3 to 4.2 kgf•m)12.7 50 to 62 (5.0 to 6.2 kgf•m)15.9 63 to 77 (6.3 to 7.7 kgf•m)37-EN 38-EN