Panasonic WU-216MF2U9 - Technical Data Manual - Page 34

2. System Design Design of 3WAY VRF SYSTEM 2-2. Example of Tubing Size Selection and Refrigerant Charge Amount Additional refrigerant charging Based on the values in Tables 2, 3, 4, 6, 9 and 10, use the liquid tubing size and length, and calculate the amount of additional refrigerant charge using the formula below. Unit of account (oz) Required additional refrigerant charge (oz) or Necessary Amount of Additional Refrigerant Charge Per Outdoor Unit = + 3.93 × (a) + 2.78 × (b) + 1.99 × (c) + 1.38 × (d) + 0.602 × (e) + 0.279 × (f) + Necessary amount of additional refrigerant charge for all indoor unit cooling capacity + 0.763 × (A) + 0.441 × (B) + 0.333 × (C) + 0.226 × (D) + 0.129 × (E) Unit of account (g) Necessary Amount of Additional Refrigerant Charge Per Outdoor Unit Required additional refrigerant charge (g) = + + 366 × (a) + 259 × (b) + 185 × (c) + 128 × (d) + 56 × (e) + Necessary amount of additional refrigerant charge for all 26 × (f) indoor unit cooling capacity 1 + 71 × (A) + 41 × (B) + 31 × (C) + 21 × (D) + 12 × (E) (a) : Liquid tubing Total length of ø7/8" (ft.) or (m) (A) : Discharge tubing Total length of ø1-1/8" (ft.) or (m) (b) : Liquid tubing Total length of ø3/4" (ft.) or (m) (B) : Discharge tubing Total length of ø7/8" (ft.) or (m) (c) : Liquid tubing (d) : Liquid tubing Total length of ø5/8" (ft.) or (m) (C) : Discharge tubing Total length of ø3/4" (ft.) or (m) Total length of ø1/2" (ft.) or (m) (D) : Discharge tubing Total length of ø5/8" (ft.) or (m) 2 (e) : Liquid tubing (f) : Liquid tubing Total length of ø3/8" (ft.) or (m) (E) : Discharge tubing Total length of ø1/2" (ft.) or (m) Total length of ø1/4" (ft.) or (m) Charging procedure Be sure to charge with R410A refrigerant in liquid form. 1. After performing a vacuum, charge with refrigerant from the liquid tubing side. At this time, all valves must be in the "fully closed" position. 2. If it was not possible to charge the designated amount, operate the system in Cooling mode while charging with refrigerant from the gas 3 tubing side. (This is performed at the time of the test run. For this, all valves must be in the "fully open" position. However, if only one outdoor unit is installed, a balance tube is not used. Therefore, leave the valves fully closed.) Charge with R410A refrigerant in liquid form. With R410A refrigerant, charge while adjusting the amount being fed a little at a time in order to prevent liquid refrigerant from backing up. After charging is completed, turn all valves to the "fully open" position. Replace the tubing covers as they were before. 4 CAUTION 1. R410A additional charging absolutely must be done through liquid charging. 2. The R410A refrigerant cylinder has a gray base color, and the top part is pink. 3. The R410A refrigerant cylinder includes a siphon tube. Check that the siphon tube is present. (This is indicated on the label at the top of the cylinder.) 4. Due to differences in the refrigerant, pressure, and refrigerant oil involved in installation, it is not possible in some cases to use the same tools for R22 and for R410A. 5 For type 72 For type 96 For type 120/144 6 7 Suction tube Discharge tube Liquid tube Balance tube 8 Use a flathead screwdriver and open (For type 72/96) (For type 120/144) Use a hex wrench (width Use a flathead Use a hex wrench (width Use a flathead 5/32 inch (4mm)) and screwdriver and open by turning the part with 15/64 inch (6mm)) and screwdriver and open turn to the left to open. by turning the part with the screw groove to the turn to the left to open. by turning the part with the screw groove to the right, from " -" to " | ". the screw groove to the right, from " -" to " | ". right, from " -" to " | ". 9 16 2 - 18