Application Data - Carrier Aquasnap 30RAP010 Product Data

Application data

Chiller location and clearances
Do not locate near sound sensitive areas without proper
acoustic consideration. For applications requiring mount-
ing a chiller on a building rooftop, consideration should be
given to using rubber-in-shear or spring isolators to mini-
mize structure-borne transmission. Unit must be level when
installed to ensure proper oil return to the compressors.
Clearances must be provided around chillers for airflow,
service and local code requirements. See dimensional
drawings for specific unit clearance requirements. Ensure
adequate clearance between
maintained.
When parallel chillers are aligned such that coils face
each other, a minimum of 6 ft (1829 mm) is recom-
mended. When the parallel arrangement has only one coil
drawing air from the space between chillers, a minimum of
3.5 ft (1067 mm) is recommended. When parallel chillers
have no coils facing each other (a back-to-back arrange-
ment), be sure to maintain the larger of the recommended
service 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 be
maintained on the side of the chiller than has an electrical
box. Chiller fan discharge must be at least as high as adja-
cent solid walls. Installation in pits is not recommended.
MULTIPLE UNIT SEPARATION
a30-4873
6 ft
(1.8 m)
MINIMUM*
* Minimum for when coils face each other. Less clearance is required
in other configurations.
† Clearance of 3.5 ft is required when a coil faces the wall. When
there is no coil facing the wall, see the certified drawing for the
required service clearance.
Oversizing chillers
Oversizing chillers by more than 15% at design conditions
must be avoided as the system operating efficiency is
adversely affected (resulting in greater or excessive electri-
cal demand). When future expansion of equipment is
anticipated, install a single chiller to meet present load
requirements and add a second chiller to meet the addi-
tional load demand. It is also recommended that 2 smaller
chillers be installed where operation at minimum load is
critical. The operation of a smaller chiller loaded to a
greater percentage over minimum is preferred to operating
a single chiller at or near its minimum recommended value.
Hot gas bypass should not be used as a means to allow
oversizing chillers. Hot gas bypass should be given consid-
eration where substantial operating time is anticipated
below the minimum unloading step.
Multiple chillers
Where chiller capacities greater than can be supplied by a
single 30RAP chiller are required, or where stand-by
adjacent chillers is
3.5 ft (1.1 m)
MINIMUM†
capability is desired, chillers may be installed in parallel.
Units may be of the same or different sizes with this piping
arrangement. However, cooler flow rates must be balanced
to ensure proper flow to each chiller.
When multiple 30RAP chillers are applied in parallel,
and the chillers include the optional hydronic package, the
individual chiller expansion tanks must be disconnected
and a single field-supplied expansion tank must be installed
in the common header.
Unit software is capable of controlling two parallel units
as a single plant by making use of the dual chiller control
feature. Refer to the Controls, Start-up, Operation, Service
and Troubleshooting guide for further details. The accesso-
ry Chillervisor System Manager can be used to ensure
proper staging sequence of up to 8 chillers. Refer to the
accessory Chillervisor System Manager installation instruc-
tions for further details.
If the dual chiller algorithm is used, and the machines are
installed in parallel, one chiller must be configured as the
master chiller and the other as the slave. With this configu-
ration, an additional leaving fluid temperature thermistor
must 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 water
pump located in its own piping. Check valves are required
at the discharge of each pump (when the factory hydronic
package option is chosen, and dual pumps are select-
ed, the check valves are automatically supplied). If
pumps are not dedicated for each chiller, then isolation
valves are required. Each chiller must open and close its
own isolation valve through the unit control (the valve must
be connected to the pump outputs).
If a series application is required, the master/slave con-
trol feature cannot be used. Hydronic pump packages may
not be applied in series applications.
PARALLEL CHILLER INSTALLATION
RETURN MASTER
FLUID CHILLER
SLAVE
CHILLER
*Depending on piping sizes, use either:
• HH79NZ014 sensor/10HB50106801 well (3-in. sensor/well)
• HH79NZ029 sensor/10HB50106802 well (4-in. sensor/well)
Series chillers
Where a large temperature drop (greater than 20 F
[11.1 C]) is desired or where chiller capacities greater than
can be supplied by a single 30RAP chiller are required or
where standby capability is required, chillers may be
installed in series. The leaving fluid temperature sensors
need not be relocated. However, the cooler minimum
entering fluid temperature limitations should be considered
for the chillers located downstream of other chillers. When
chillers are operated in a series arrangement, the use of a
Chillervisor System Manager is recommended.
THERMISTOR
WIRING*
LEAVING
FLUID
INSTALL DUAL CHILLER LWT
LEAVING FLUID TEMPERATURE
THERMISTOR (T10) HERE
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