Daikin AVS Installation Manual

Also see for AVB: Installation and maintenance manual

Contents

Daikin AVS Installation Manual Manual pdf 32 page image

Page 32 of 60 IM 817-4Do not force adjustment stem of TXV. When adjusting superheatsetting, there are a maximum of 10 turns on the stem. Turningadjustment stem after reaching stop will damage valve.Table 22 —Saturated Temperature - Pressure Chart(ºF) R410A-PSIG (ºF) R410A-PSIG (ºF) R410A-PSIG32 101.1 44 127.7 80 235.833 103.2 45 130.2 85 254.734 105.2 46 132.6 90 274.535 107.4 47 135.1 95 295.536 109.5 48 137.5 100 317.637 111.7 49 140.1 105 340.938 113.9 50 142.6 110 365.439 116.2 55 147.0 115 391.240 118.4 60 170.1 120 418.341 120.7 65 185.2 125 446.942 123.0 70 201.1 130 476.843 125.4 75 218.0 140 541.4Determining System SuperheatAfter the subcooling has been determined, check system superheat.1. Determine required superheat from superheat range, table 23.2. Measure suction line temperature 6 inches from service valve.3. Measure suction line pressure at service valve and determinesaturated suction temperature from table 22.4. Subtract saturated suction temperature from measured temperatureto obtain superheat.5. Refer to table 23 and adjust charge as required for correct superheatat ambient conditions.Each time that charge is added or removed from the system,allow the system to run approximately 20 - 30 minutes beforepressure and temperature readings are taken and superheatcalculations made.If system hunting occurs or subcooling is reduced, it may benecessary to adjust TXV to obtain correct superheat.Superheat Adjustment1. Remove the seal cap from thermal expansion valve (see figure 91).2. Turn the adjustment screw clockwise to increase superheat andcounterclockwise to decrease superheat (see figure 91). Onecomplete 360º turn changes the superheat approximately 3-4ºF,regardless of the refrigerant type. As much as 30 minutes may berequired for the system to stabilize after the adjustment is made.3. Replace and hand-tighten seal cap.Figure 91 - Superheat Adjustment of TXVSuperheatAdjustment ScrewCounterclockwise ToDecrease Superheat Clockwise To IncreaseSuperheatRemove Seal CapOutdoor Indoor Coil Air Inlet Temp.Ambient DB/WB (50% RH)75/63 80/67 85/71105 * * 8-10100 * 3-5 9-1195 * 5-7 11-1390 * 9-11 13-1585 5-7 10-12 15-1780 8-10 12-14 18-2075 10-12 15-17 21-2370 13-15 19-21 24-2665 15-17 21-23 26-28Table 23 —Superheat RangeTypical conditions - 95ºF ambient, 75 psig suction, 285 psighead pressure, 6 - 7º superheat, 15ºF subcoolingNOTICENOTICECAUTIONNOTICE