Piping Work And Refrigerant Charge - Hitachi RAS-(3-6)HVNC1(E) Service Manual

3 Piping work and
refrigerant charge
Index
3.1. General notes before performing pipe work .......................................................................................... 62
3.1.1. Piping Materials ......................................................................................................................................... 62
3.1.2. Three principles on refrigerant piping work ............................................................................................... 64
3.1.3. Suspension of refrigerant piping ................................................................................................................ 64
3.1.4. Brazing work .............................................................................................................................................. 65
3.2. Piping connection for outdoor unit ......................................................................................................... 66
3.2.1. RAS-(2-2.5)HVNP1 / RAS-3HVNC1 .......................................................................................................... 66
3.2.2. RAS-3HVNP1E / RAS-(4-6)H(V)N(P/C)1E / RAS-(8-10)HN(P/C)E / RAS-12HN(P/C) ............................. 67
3.2.3. Outdoor unit stop valve .............................................................................................................................. 70
3.3. Refrigerant piping range ........................................................................................................................ 72
3.3.1. Refrigerant piping length ........................................................................................................................... 72
3.3.2. Piping system for header branch ............................................................................................................... 72
3.3.3. Piping system for line branch .................................................................................................................... 75
3.3.4. Combinations of piping size and piping length .......................................................................................... 76
3.3.5. Refrigerant piping size and multikit/distributor selection ............................................................................ 77
3.3.6. System installation ..................................................................................................................................... 80
3.3.7. Connecting flare adapter ........................................................................................................................... 82
3.4. Refrigerant charge................................................................................................................................. 83
3.4.1. Caution of the pressure by check joint ...................................................................................................... 84
3.4.2. Refrigerant charge quantity ....................................................................................................................... 84
3.5. Caution in case of refrigerant leakage................................................................................................... 89
3.5.1. Maximum permitted concentration of hydrofluorocarbon (HFC) ................................................................ 89
3.5.2. Calculation of refrigerant concentration ..................................................................................................... 89
3.5.3. Countermeasure for refrigerant leakage .................................................................................................... 89
3.6. Compatibility with the piping of current installations where R22 or R407C is used .............................. 90
3.6.1. Installation procedure for existing pipes .................................................................................................... 90
3.6.2. When existing air-conditioner is a product of another manufacturer ......................................................... 90
3.6.3. Renewal kit selection model ...................................................................................................................... 92
3.7. Drain piping ........................................................................................................................................... 96
3.7.1. Drain discharging boss .............................................................................................................................. 96
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SMGB0087 rev.0 - 12/2013
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P i p i n g w o r k a n d r e f r i g e r a n t c h a r g e
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