Carrier AquaForce 30XA Series Installation Instructions Manual page 126

DX Cooler Units with Hydronic Pump Package
The 30XA092-162 units can be equipped with a factory-installed
hydronic pump package consisting of a suction guide/strainer,
pump, combination valve, internal piping and wiring connected at
the factory.
The combination valve performs the following functions:
• drip-tight shut-off valve
• spring closure design with a non-slam check valve
• flow-throttling valve
When facing the cooler side of unit, the inlet (return) water con-
nection is located on the right side of cooler. The outlet (supply)
water connection is on the left side of cooler. The inlet is connect-
ed to the suction guide/strainer of the pump via a Victaulic-type
connection. The cooler supply has water-side Victaulic-type con-
nections (follow connection directions as provided by the cou-
pling manufacturer). Provide proper support for the piping. If ac-
cessory security grilles have been added, holes must be cut in the
grilles for field piping and insulation.
The combination valve is not installed during shipping and must
be field installed during installation of the chiller. The valve is
mounted internal to the unit to protect it during shipping. Remove
the valve from its shipping location and mount it to the base frame
using the 4 screws that supported the valve during shipping. The
valve should be connected to the water outlet of the cooler using
the Victaulic coupling which is provided (Fig. 52).
Fig. 52 — Balancing Valve
The suction guide/strainer is shipped from the factory with a run-
in screen. This screen is a temporary device used during the start-
up/clean-up process of the chilled water circuit to prevent con-
struction debris from damaging the pump or internal tubes of the
cooler. After all debris has been removed, or a maximum of 24
running hours, the temporary screen must be removed. See the
Start-Up, Controls, Operation and Troubleshooting guide for fur-
ther information.
CAUTION
The suction guide/strainer is shipped from the factory with a
run-in screen. This temporary screen must be removed after all
debris has been removed or a maximum of 24 running hours.
Failure to remove the temporary screen may result in damage
to the pump or cooler.
NOTE: It is required that a 20 mesh field-supplied strainer be in-
stalled in the inlet piping to the cooler on open loop systems.
A / in. NPT fitting is installed in the inlet piping of the pump for
3
4
connection to an expansion tank. Install the tank in accordance
with the manufacturer's instructions.
Figure 50 illustrates typical dual pump package.
Three drain connections are provided and are located at the bot-
tom of the cooler shell located near water outlet, pump volute, and
the suction guide. See Fig. 2-27 for connection location. Insulate
the drain piping (in the same manner as the chilled water piping)
for at least 12 in. (305 mm) from the cooler.
DX Cooler Units without Hydronic Pump Package
When facing the cooler side of the unit, the inlet (return) water
connection is located on the right side of cooler. It is required that
a field-supplied strainer with a minimum size of 20 mesh be in-
stalled within 10 ft (3.05 m) of the cooler inlet to prevent debris
from damaging internal tubes of the cooler. The outlet (supply)
water connection is on the left side of cooler. The cooler has wa-
ter-side Victaulic-type connections (follow connection directions
as provided by the coupling manufacturer). Provide proper sup-
port for the piping. If accessory security grilles have been added,
holes must be cut in the grilles for field piping and insulation. See
Fig. 45 for a typical piping diagram of a 30XA unit without a hy-
dronic pump package.
A drain connection is located at the bottom of the cooler shell near
the water outlet end of the cooler. See Fig. 2-27 for connection lo-
cation. Insulate the drain piping (in the same manner as the chilled
water piping) for at least 12 in. (305 mm) from the unit.
DX Cooler Dual Chiller Control
The ComfortLink controller allows two chillers (piped in parallel
or series) to operate as a single chilled water plant with standard
control functions coordinated through the master chiller controller.
This standard ComfortLink feature requires a communication link
between the two chillers on the CCN Bus.
There are several advantages to this type of control:
• redundancy (multiple circuits)
• better low load control, (lower tonnage capability)
• lower rigging lift weights (two machines rather than one
large machine)
• chiller lead-lag operation (evens the wear between the two
machines)
DX Cooler Dual Chiller Leaving Water Sensor
If the dual chiller algorithm is used, and the machines are installed
in parallel, a dual chilled water sensor must be installed for each
module. Install the well in the common leaving water header. See
Fig. 50.
DX Cooler Parallel Dual Chiller Operation
Parallel chiller operation is the recommended option for dual
chiller control. In this case, each chiller must control its own dedi-
cated pump or isolation valve. Balancing valves are recommended
to insure proper flow in each chiller. Two field-supplied and in-
stalled dual chiller leaving water temperature sensors are required,
one for each module for this function to operate properly.
Consider adding additional isolation valves to isolate each chiller
to allow for service on a machine, and still allow for partial capac-
ity from the other chiller. See Fig 50.
DX Cooler Series Dual Chiller Operation
Series chiller operation is an alternate method supported by the
ComfortLink control system but is not recommended for DX ap-
plications. Certain applications with high temperature rise across
the units may require that two chillers be connected in series.
DX Cooler Pump Control
It is recommended that cooler pump control be utilized on all
chillers unless the chilled water pump runs continuously or the
chilled water system contains a suitable antifreeze solution. Con-
trol of dual external pumps requires installation of the external
pump control accessory package (Part No. 00EFN900003200A).
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