Carrier Aquasnap 30RAP070 Product Data

Also see for Aquasnap 30RAP010: Installation instructions Operation and service guide Start up & operation manual Product data

Contents

Carrier Aquasnap 30RAP070 Product Data Manual pdf 61 page image

61Chiller location and clearancesDo not locate near sound sensitive areas without properacoustic consideration. For applications requiring mount-ing a chiller on a building rooftop, consideration should begiven to using rubber-in-shear or spring isolators to mini-mize structure-borne transmission. Unit must be level wheninstalled to ensure proper oil return to the compressors.Clearances must be provided around chillers for airflow,service and local code requirements. See dimensionaldrawings for specific unit clearance requirements. Ensureadequate clearance between adjacent chillers ismaintained.For 30RAP010-060: When parallel chillers are alignedsuch that coils face each other, a minimum of 6 ft(1829 mm) is recommended. When the parallel arrange-ment has only one coil drawing air from the space betweenchillers, a minimum of 3.5 ft (1067 mm) is recommended.When parallel chillers have no coils facing each other (aback-to-back arrangement), be sure to maintain the largerof the recommended service clearances associated witheach chiller (see the certified drawings). Due to NEC(National Electric Code, U.S.A.) regulations, a minimumclearance of 4 ft (1219 mm) must be maintained on theside of the chiller that has an electrical box. Chiller fan dis-charge must be at least as high as adjacent solid walls.Installation in pits is not recommended.For 30RAP070-090: When chillers are arranged in par-allel, a minimum of 10 ft (3048 mm) between chillers isrecommended. Acceptable clearance on the cooler con-nection side or end opposite the control box of the unitcan be reduced to 3 ft (1 m) without sacrificing perfor-mance as long as the remaining three sides areunrestricted. Acceptable clearance on the side with a con-trol box can be reduced to 4 ft (1.3 m) due to NEC(National Electric Code) regulations, without sacrificingperformance as long as the remaining three sides areunrestricted. Clearances between chillers in dual chillerapplications may be reduced to 6 ft (1.8 m) without sacri-ficing performance provided the remaining sides are unre-stricted. For acceptable clearance with layout involvingmore than 2 chillers, please contact application engineer-ing.Oversizing chillersOversizing chillers by more than 15% at design conditionsmust be avoided as the system operating efficiency isadversely affected (resulting in greater or excessive electri-cal demand). When future expansion of equipment isanticipated, install a single chiller to meet present loadrequirements and add a second chiller to meet the addi-tional load demand. It is also recommended that 2 smallerchillers be installed where operation at minimum load iscritical. The operation of a smaller chiller loaded to agreater percentage over minimum is preferred to operatinga single chiller at or near its minimum recommended value.Hot gas bypass should not be used as a means to allowoversizing chillers. Hot gas bypass should be given consid-eration where substantial operating time is anticipatedbelow the minimum unloading step.Multiple chillersWhere chiller capacities greater than can be supplied by asingle 30RAP chiller are required, or where stand-bycapability is desired, chillers may be installed in parallel.Units may be of the same or different sizes with this pipingarrangement. However, cooler flow rates must be balancedto ensure proper flow to each chiller.When multiple 30RAP chillers are applied in parallel,and the chillers include the optional hydronic packagewhich contain expansion tanks (sizes 010-060), the indi-vidual chiller expansion tanks must be disconnected and asingle field-supplied expansion tank must be installed in thecommon header.Unit software is capable of controlling two parallel unitsas a single plant by making use of the dual chiller controlfeature. Refer to the Controls, Start-up, Operation, Serviceand Troubleshooting guide for further details. The accesso-ry Chillervisor System Manager can be used to ensureproper staging sequence of up to 8 chillers. Refer to theaccessory Chillervisor System Manager installation instruc-tions for further details.If the dual chiller algorithm is used, and the machines areinstalled in parallel, one chiller must be configured as themaster chiller and the other as the slave. With this configu-ration, an additional leaving fluid temperature thermistormust be installed as shown in the figure below.Parallel chiller control with dedicated pumps is recom-mended. The chiller must start and stop its own waterpump located in its own piping. Check valves are requiredat the discharge of each pump (when the factory hydronicpackage option is chosen, and dual pumps are select-ed, the check valves are automatically supplied). Ifpumps are not dedicated for each chiller, then isolation6 ft(1.8 m)MINIMUM*3.5 ft (1.1 m)MINIMUM†30RAP010-060 MULTIPLE UNIT SEPARATION* Minimum for when coils face each other. Less clearance is requiredin other configurations.† Clearance of 3.5 ft is required when a coil faces the wall. Whenthere is no coil facing the wall, see the certified drawing for therequired service clearance.a30-487310 ft(3 m)MINIMUM6 ft (1.8 m)MINIMUM30RAP070-090 MULTIPLE UNIT SEPARATIONa30-4904Application data