Daikin ARXM25M2V1B Installation Manual page 10

Outdoor Unit Installation
4-2 Selection of copper and heat insulation materials
When using commercial copper pipes and fittings, observe the following:
1) Insulation material: Polyethylene foam
Heat transfer rate: 0.041 to 0.052W/mK (0.035 to 0.045kcal/mh°C)
Refrigerant gas pipe's surface temperature reaches 110°C max.
Choose heat insulation materials that will withstand this temperature.
2) Be sure to insulate both the gas and liquid piping and to provide insulation
dimensions as below.
Gas side
O.D. 9.5mm
Minimum bend radius
Thickness 0.8mm (C1220T-O)
3) Use separate thermal insulation for gas and liquid refrigerant pipes.
5.
Evacuating the air with a vacuum pump and checking gas leakage
WARNING
• Do not mix any substance other than the specified refrigerant (R32) into the refrigeration cycle.
• When refrigerant gas leaks occur, ventilate the room as soon and as much as possible.
• R32, as well as other refrigerants, should always be recovered and never be released directly into the environment.
• Use a vacuum pump for R32 or R410A exclusively. Using the same vacuum pump for different refrigerants may damage the
vacuum pump or the unit.
• Use tools for R32 or R410A (such as the gauge manifold, charging hose, or vacuum pump adapter).
• When piping work is completed, it is necessary to evacuate the air and check for gas
leakage.
• If using additional refrigerant, perform air evacuating from the refrigerant pipes
and indoor unit using a vacuum pump, then charge additional refrigerant.
• Use a hexagonal wrench (4mm) to operate the stop valve rod.
• All refrigerant pipe joints should be tightened with a torque wrench at the specified
tightening torque.
1) Connect projection side of charging hose (which comes from gauge manifold) to gas stop valve's service port.
2) Fully open gauge manifold's low-pressure valve (Lo) and completely close its high-pressure valve (Hi).
(High-pressure valve subsequently requires no operation.)
3) Do vacuum pumping and make sure that the compound pressure gauge reads –0.1MPa (–76cmHg).*1
4) Close gauge manifold's low-pressure valve (Lo) and stop vacuum pump.
(Keep this state for a few minutes to make sure that the compound pressure gauge pointer does not swing back.)*2
5) Remove caps from liquid stop valve and gas stop valve.
6) Turn the liquid stop valve's rod 90 degrees counterclockwise with a hexagonal wrench to open valve.
Close it after 5 seconds, and check for gas leakage.
Using soapy water, check for gas leakage from indoor unit's flare and outdoor unit's flare and valve rods.
After the check is complete, wipe all soapy water off.
7) Disconnect charging hose from gas stop valve's service port, then fully open liquid and gas stop valves.
(Do not attempt to turn valve rod beyond its stop.)
8) Tighten valve caps and service port caps for the liquid and gas stop valves with a torque wrench at the specified torques.
7
Liquid side
O.D. 6.4mm
30mm or more
Gas pipe Liquid pipe
thermal insulation thermal insulation
I.D. 12-15mm I.D. 8-10mm
Thickness 10mm Min.
Inter-unit wire
Gas pipe
Gas pipe
insulation
Finishing tape
Compound Pressure
pressure gauge metre
Gauge
manifold
Valve caps
High-
Low-pressure
pressure
valve
valve
Charging
hoses
Vacuum pump Service port
Gas stop valve
Liquid pipe
Liquid pipe
insulation
Drain hose
Liquid
stop
valve
English