York H3CE180 Installation Instructions Manual

Also see for H3CE180: User guide

Contents

REFRIGERANT PIPINGGENERAL GUIDELINESMany service problems can be avoided by taking adequate pre-cautions to provide an internally clean and dry system and by usingprocedures and materials that conform with established standards.Use hard drawn copper tubing where no appreciable amountof bending around pipes or other obstructions is necessary.Use long radius ells wherever possible with one exception—short radius ells for the traps in all suction risers. If soft copperis used, care should be taken to avoid sharp bends which maycause a restriction.Pack fiber glass insulation and a sealing material such aspermagum around refrigerant lines where they penetrate a wallto reduce vibrations and to retain some flexibility.Support all refrigerant lines at minimum intervals with suitablehangers, brackets or clamps.Braze all copper to copper joints with Silfos-5 or equivalentbrazing material. Do not use soft solder.Insulate all suction lines with a minimum of 1/2" ARMAFLEX orequal. Liquid lines exposed to direct sunlight and/or high tem-peratures must also be insulated.Never solder suction and liquid lines together. They can be tapedtogether for convenience and support purposes, but they must becompletely insulated from each other.A filter-drier MUST be installed in the liquid line of every systemto prevent dirt and moisture from damaging the system. A prop-erly-sized filter-drier is shipped with each condensing unit for fieldinstallation near the evaporator coil. The filter-drier is shippedinside the unit control box.NOTE: Installing a filter-drier does not eliminate the need forthe proper evacuation of a system before it is charged.A moisture indicating sight-glass may be field installed in liquidline(s) between the filter-drier and the evaporator coil. Themoisture indicating sight-glass can be used to check for excessmoisture in the system or used as visual means to verifyrefrigerant charge.LINE SIZINGWhen sizing refrigerant lines for a split-system air conditioner,check the following:1. Suction line pressure drop due to friction at full capacity,2. Liquid line pressure drop due to friction at full capacity,3. Suction line velocity for oil return at part capacity, and4. Liquid line pressure drop due to static head.NOTE: Never base refrigerant line sizes on the OD of thesuction and liquid connections on the unit.Tables 4 and 5 list friction losses for both the suction and liquidlines on the system. Table 6 shows the amount of refrigerantcharge required per foot of refrigerant line.When the evaporator coil is below the condensing unit, thesuction line must be sized for both pressure drop and for oilreturn. For certain piping arrangements, different suction linesizes may have to be used. The velocity of the suction gas mustalways be great enough to carry oil back to the compressor.When the condensing unit is below the evaporator coil, theliquid line must be designed for the pressure drop due to bothfriction loss and vertical rise. If the total pressure drop exceeds40 psi, some refrigerant may flash before it reaches the thermalexpansion valve. This flashing will not only cause erratic valveoperation and poor system performance, but could also dam-age the expansion valve.SERVICE VALVESThese condensing units have service valves on the compres-sor suction line and on the liquid line leaving the condenser coil.The liquid and suction line service valves are shipped from thefactory front-seated and closed with the valve stem in themaximum clockwise position.The liquid and suction line service valves have a 1/4" male flareaccess port for evacuating, charging and pressure checking thesystem.NOTE: Never remove a cap from an access port unless thevalve is fully back-seated with its valve stem in themaximum counter-clockwise position because the re-frigerant charge will be lost. ALWAYS USE A REFRIG-ERATION VALVE WRENCH TO OPEN AND CLOSETHESE SERVICE VALVES.ModelDesignationNominalCapacity(Tons)RefrigerantFlow Rate3(Lbs./Min.)Type LCopper Tubing(Inches O.D.)RefrigerantGasVelocity(FT./Min.)FrictionLoss4,5(PSI/100 Ft.)180 MbhFullCapacity 15 45 1-5/82-1/8230013602.50.6PartCapacity 8-1/2 25.5 1-5/82-1/811507706 0.70.2240 MbhFullCapacity 20 601-5/82-1/82-5/83120180012004.31.20.4PartCapacity 10 301-5/82-1/82-5/81560900660061.20.30.11All horizontal suction lines should be pitched at least 1 inch every 20 feet in the direction of the refrigerant flow to aid the return of oil to the compressor.2Every vertical suction riser greater than 25 feet in height should have a “P” trap at the bottom to facilitate the return of oil to the compressor. Use short radius fittings for these traps.3Based on Refrigerant-22 at the nominal capacity of the condensing unit, a suction temperature of 40°F and a liquid temperature of 105°F.4Although suction lines should be sized for a friction loss equivalent to a 2°F change in saturation temperature (or approximately 3 psi), sizing the lines for the proper return of oilis more important.5These friction losses do not include any allowances for valves or fittings.6Since the refrigerant gas velocity may be too low to maintain good oil return up a vertical riser, use the next smaller size. The larger size may be used for horizontal runs for a smallerpressure drop.TABLE 4 - SUCTION LINES 1,2550.23-N6YUnitary Products Group 7