Carrier Aquasnap 30RAP010 Product Data

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

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Carrier Aquasnap 30RAP010 Product Data Manual pdf 47 page image

47Chiller 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.When parallel chillers are aligned such that coils faceeach other, a minimum of 6 ft (1829 mm) is recom-mended. When the parallel arrangement has only one coildrawing air from the space between chillers, a minimum of3.5 ft (1067 mm) is recommended. When parallel chillershave no coils facing each other (a back-to-back arrange-ment), be sure to maintain the larger of the recommendedservice clearances associated with each chiller (see the cer-tified drawings). Due to NEC (National Electric Code) regu-lations, a minimum clearance of 4 ft (1219 mm) must bemaintained on the side of the chiller than has an electricalbox. Chiller fan discharge must be at least as high as adja-cent solid walls. Installation in pits is not recommended.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 package, theindividual chiller expansion tanks must be disconnectedand a single field-supplied expansion tank must be installedin the common 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 isolationvalves are required. Each chiller must open and close itsown isolation valve through the unit control (the valve mustbe connected to the pump outputs).If a series application is required, the master/slave con-trol feature cannot be used. Hydronic pump packages maynot be applied in series applications.Series chillersWhere a large temperature drop (greater than 20 F[11.1 C]) is desired or where chiller capacities greater thancan be supplied by a single 30RAP chiller are required orwhere standby capability is required, chillers may beinstalled in series. The leaving fluid temperature sensorsneed not be relocated. However, the cooler minimumentering fluid temperature limitations should be consideredfor the chillers located downstream of other chillers. Whenchillers are operated in a series arrangement, the use of aChillervisor System Manager is recommended.6 ft(1.8 m)MINIMUM*3.5 ft (1.1 m)MINIMUM†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.a30-4873MASTERCHILLERSLAVECHILLERLEAVINGFLUIDRETURNFLUIDTHERMISTORWIRING*INSTALL DUAL CHILLER LWTLEAVING FLUID TEMPERATURETHERMISTOR (T10) HERE*Depending on piping sizes, use either:• HH79NZ014 sensor/10HB50106801 well (3-in. sensor/well)• HH79NZ029 sensor/10HB50106802 well (4-in. sensor/well)PARALLEL CHILLER INSTALLATIONApplication data