Dx Cooler Units - Carrier AquaForce 30XA Series Installation Instructions Manual

Air-cooled liquid chillers
Hide thumbs Also See for AquaForce 30XA Series:
Table of Contents

Advertisement

OPT
OPT
Fig. 47 — Series Dual Chiller Operation (Not Recommended for DX Cooler)
IMPORTANT: Automatic vents should be located in
accessible locations for maintenance purposes and pro-
tected from freezing.
Flooded Cooler—Cooler Pump Control
It is required that cooler pump control be utilized on all chillers
unless the chilled water pump runs continuously or the chilled wa-
ter system contains a suitable antifreeze solution. Control of dual
external pumps requires installation of the external pump control
accessory package (Part No. 00EFN900003200A).
CAUTION
Applications that utilize fresh water as the circulated fluid re-
quire that the circulating pump be controlled directly by the
chiller. Operation with fresh water is not fail-safe should there
be a loss of power to the chiller or to the circulating pump.
Freeze damage due to power loss or disabling chiller pump
control in fresh water systems will impair or otherwise nega-
tively affect the warranty.
It is required that the chiller be electrically interlocked with the
chilled water pump starter. The interlock should be wired to termi-
nals TB5-1 and TB5-2. If cooler pump control is not utilized, it is
also required that the cooler pump output be used as an override to
the chilled water pump control circuit to provide additional freeze
protection.
Refer to the control and power wiring schematic on page 134 for
proper connection of the cooler pump (PMP1 and PMP2). The
cooler pump output will remain energized for 30 seconds after all
compressors stop due to an OFF command. In the event a freeze
protection alarm is generated, the cooler pump output will be ener-
gized regardless of the cooler pump control software configura-
tion. The cooler pump output is also energized anytime a compres-
sor is started and when certain alarms are generated. A thermal
flow sensor is factory installed in the entering fluid nozzle to pre-
vent operation without flow through the cooler. See Fig. 48. The
flow sensor is factory wired.
Proper software configuration of the cooler pump control parame-
ters is required to prevent possible cooler freeze-up. Refer to the
Controls, Start-Up, Operation, Service and Troubleshooting guide
for more information.
CONTROL
BOX
SLAVE CHILLER
CONTROL
BOX
MASTER CHILLER
OPT
PUMP
OPT
OPT
Fig. 48 — Thermal Flow Sensor
Flooded Cooler Brine Units
For operating units with fluid temperatures less than 40 F (4.4 C),
add sufficient inhibited glycol or other suitable corrosion-resistant
antifreeze solution to prevent cooler freeze-up.

DX COOLER UNITS

NOTE: It is recommended for units with the hydronic package
that an inlet isolation (shut-off) valve be placed exterior to the unit
to allow removal and service of the entire pump assembly, if nec-
essary. The hydronic package is supplied from the factory with a
combination valve for isolation of leaving water. Also, if the unit
is isolated with valves, a properly sized pressure relief valve is rec-
ommended and should be installed in the piping between the unit
and the valves, following all applicable local codes. Typical piping
diagrams are shown in Fig. 49-51.
DX Cooler Air Separation
For proper system operation, it is essential that water loops be in-
stalled with proper means to manage air in the system. Free air in
the system can cause noise, reduce terminal output, stop flow, or
even cause pump failure due to pump cavitation. For closed sys-
tems, equipment should be provided to eliminate all air from the
system.
The amount of air that water can hold in solution depends on the
pressure and temperature of the water/air mixture. Air is less solu-
ble at higher temperatures and at lower pressures. Therefore, sepa-
ration can best be done at the point of highest water temperature
and lowest pressure. Typically, this point would be on the suction
side of the pump as the water is returning from the system or ter-
minals. This is generally the optimal place to install an air separa-
tor, if possible.
1. Install automatic air vents at all high points in the system. (If
the 30XA unit is located at the high point of the system, a
vent can be installed on the cooler shell on the
male port.)
123
a30-5295
LEGEND
Field-Installed Communication Bus (slashes
indicate number of conductor wires)
Field-Installed Wiring
Optional Piping
Isolation Valve
a30-5238
/
1
4
in. NPT fe-

Hide quick links:

Advertisement

Table of Contents
loading

Table of Contents