Carrier Aquazone 50PCH Installation, Start-up And Service Instructions Manual

Contents

11Step 7 — Pipe Connections — Depending on theapplication, there are 3 types of WSHP piping systems tochoose from: water loop, ground-water and ground loop. Referto Piping Section of Carrier System Design Manual for addi-tional information.All WSHP units use low temperature soldered female pipethread fittings for water connections to prevent annealing andout-of-round leak problems which are typically associated withhigh temperature brazed connections. Refer to Tables 1 and 2for connection sizes. When making piping connections, con-sider the following:• Use a backup wrench when making screw connections tounit to prevent internal damage to piping.• Insulation may be required on piping to avoid condensa-tion in the case where fluid in loop piping operates attemperatures below dew point of adjacent air.• Piping systems that contain steel pipes or fittings maybe subject to galvanic corrosion. Dielectric fittings maybe used to isolate the steel parts of the system to avoidgalvanic corrosion.WATER LOOP APPLICATIONS — Water loop applicationsusually include a number of units plumbed to a common pip-ing system. Maintenance to any of these units can introduce airinto the piping system. Therefore, air elimination equipmentcomprises a major portion of the mechanical room plumbing.The flow rate is usually set between 2.25 and 3 gpm per tonof cooling capacity. For proper maintenance and servicing,pressure-temperature (P/T) ports are necessary for temperatureand flow verification.In addition to complying with any applicable codes, consid-er the following for system piping:• Piping systems using water temperatures below 50°Frequire 1 /2-in. closed cell insulation on all piping surfacesto eliminate condensation.• Avoid all plastic to metal threaded fittings due to thepotential to leak. Use a flange fitted substitute.• Teflon tape thread sealant is recommended to minimizeinternal fouling of the heat exchanger.• Use backup wrench. Do not overtighten connections.• Route piping to avoid service access areas to unit.• Flush the piping system prior to operation to remove dirtand foreign materials from the system.GROUND LOOP APPLICATIONS — Temperatures be-tween 25 and 110°F and a cooling capacity of 2.25 to 3 gpm offlow per ton are recommended. In addition to complying withany applicable codes, consider the following for system piping:• Limit piping materials to only polyethylene fusion in theburied sections of the loop.• Do not use galvanized or steel fittings at any time due tocorrosion.• Avoid all plastic to metal threaded fittings due to the poten-tial to leak. Use a flange fitted substitute.• Do not overtighten connections.• Route piping to avoid service access areas to unit.• Use pressure-temperature (P/T) plugs to measure flow ofpressure drop.INSTALLING SUPPLY AND RETURN HOSE KIT —Follow these piping guidelines:1. Install a drain valve at the base of each supply and returnriser to facilitate system flushing.2. Install shutoff/balancing valves and unions at each unit topermit unit removal for servicing.3. Place strainers at the inlet of each system circulatingpump.4. Select the proper hose length to allow slack between con-nection points. Hoses may vary in length by +2% to –4%under pressure.5. Do not exceed the minimum bend radius for the hose se-lected. Refer to Table 5. Exceeding the minimum bend ra-dius may cause the hose to collapse, which reduces waterflow rate. Install an angle adapter to avoid sharp bendsin the hose when the radius falls below the requiredminimum.NOTE: Piping must comply with all applicable codes.Table 5 — Metal Hose Minimum Bend RadiiInsulation is not required on loop water piping except wherethe piping runs through unheated areas or outside the buildingor when the loop water temperature is below the minimum ex-pected dew point of the pipe ambient. Insulation is required ifloop water temperature drops below the dew point.Pipe joint compound is not necessary when Teflon* thread-ed tape is pre-applied to hose assemblies or when flared-endconnections are used. If pipe joint compound is preferred, usecompound only in small amounts on the male pipe threads ofthe fitting adapters. Prevent sealant from reaching the flaredsurfaces of the joint.NOTE: When anti-freeze is used in the loop, assure that it iscompatible with Teflon tape or pipe joint compound employed.Maximum allowable torque for brass fittings is 30 ft-lb. If atorque wrench is not available, tighten finger-tight plus onequarter turn. Tighten steel fittings as necessary.Optional pressure-rated hose assemblies designed specifi-cally for use with Carrier units are available. Similar hoses canbe obtained from alternate suppliers. Supply and return hosesare fitted with swivel-joint fittings at one end to prevent kink-ing during installation.Male adapters secure hose assemblies to the unit and risers.Install hose assemblies properly and check them regularly toavoid system failure and reduced service life. See Fig. 11.Fig. 11 — Supply/Return Hose KitHOSE DIAMETER (in.) MINIMUM BEND RADII (in.)1 / 2 2 1 / 23 / 4 41 5 1 / 2IMPORTANT: Do not bend or kink supply lines or hoses.CAUTIONBackup wrench is required when tightening water connec-tions to prevent water line damage. Failure to use a backupwrench could result in equipment damage.RIBCRIMPEDLENGTH(2 ft LENGTH STANDARD)SWIVELBRASSFITTING BRASSFITTINGMPT* Registered trademark of DuPont.