Piping Work And Refrigerant Charge - Hitachi RAS-2-HVNP Service Manual

3. Piping work and refrigerant charge

Index
3.1. General notes before performing pipe work .......................................................................................... 52
3.1.1. Piping Materials ......................................................................................................................................... 52
3.1.2. Three principles on refrigerant piping work ............................................................................................... 54
3.1.3. Suspension of refrigerant piping ................................................................................................................ 54
3.1.4. Brazing work .............................................................................................................................................. 55
3.2. Piping connection for outdoor unit ......................................................................................................... 56
3.2.1. RAS-(2-2.5)HVNP / RAS-3HVNC .............................................................................................................. 56
3.2.2. RAS-3HVNPE / RAS-(4-6)H(V)N(P/C)E / RAS-(8-10)HN(P/C)E / RAS-12HN(P/C) ................................. 57
3.2.3. Outdoor unit stop valve .............................................................................................................................. 60
3.3. Refrigerant piping range ........................................................................................................................ 62
3.3.1. Refrigerant piping length ........................................................................................................................... 62
3.3.2. Piping system for header branch ............................................................................................................... 62
3.3.3. Piping system for line branch .................................................................................................................... 65
3.3.4. Combinations of piping size and piping length .......................................................................................... 66
3.3.5. Refrigerant piping size and multikit/distributor selection ............................................................................ 67
3.3.6. System installation ..................................................................................................................................... 70
3.3.7. Connecting flare adapter ........................................................................................................................... 71
3.4. Refrigerant charge................................................................................................................................. 72
3.4.1. Caution of the pressure by check joint ...................................................................................................... 73
3.4.2. Refrigerant charge quantity ....................................................................................................................... 74
3.5. Caution in case of refrigerant leakage................................................................................................... 78
3.5.1. Maximum permitted concentration of hydrofluorocarbon (HFC) ................................................................ 78
3.5.2. Calculation of refrigerant concentration ..................................................................................................... 78
3.5.3. Countermeasure for refrigerant leakage .................................................................................................... 78
3.6. Piping work for compatibility with the piping of current installations where is used R22 or R407C. .... 79
3.6.1. Installation procedure for existing pipes .................................................................................................... 79
3.6.2. When existing Air-Conditioner is a product of another manufacturer ........................................................ 79
3.6.3. Permissible range for existing Air-Conditioning Pipes
(Pipe length in the case of "without cleaning process". ........................................................................................... 80
3.6.4. Renewal kit selection model ...................................................................................................................... 81
3.7. Drain piping ........................................................................................................................................... 85
3.7.1. Drain discharging boss .............................................................................................................................. 85
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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
SMGB0079 rev.0 - 01/2013
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