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7.3 - Flow control
Evaporator flow switch and chilled water pump interlock
IMPORTANT: On 30XB & XBP units, the unit water flow switch
must be energised. Failure to follow this instruction will void
the Carrier guarantee.
The water flow switch is installed on the evaporator water inlet
and adjusted by the control, based on unit size and application. If
adjustment is necessary, it must be carried out by qualified
personnel trained by Carrier Service.
7.4 - Evaporator water box bolt tightening
The evaporator (and condenser) are of the shell and tube type with
removable water boxes to facilitate cleaning. Re-tightening or
tightening must be done in accordance with the illustration below.
Water box tightening sequence
Legend:
1 Sequence 1: 1, 2, 3, 4
2 Tightening torque
Sequence 2: 5, 6, 7, 8
Bolt size M16 - 171 - 210 Nm
Sequence 3: 9, 10, 11, 12
Sequence 4: 13, 14, 15, 16
NOTE: Before this operation we recommend draining the
circuit and disconnecting the pipes to be sure that the bolts
are correctly and uniformly tightened.
7.5 - Frost protection
7.5.1 - Standard machine
If the chiller or the water piping is in an area where the ambient
temperature can fall below 0 °C it is recommended to add an
antifreeze solution to protect the unit and the water piping to a
temperature of 10 K below the lowest temperature likely to be
reached at the installation site. Use only antifreeze solutions,
approved for heat exchanger duty. If the system is not protected
by an antifreeze solution and will not be used during the freezing
weather conditions, draining of the cooler and outdoor piping is
mandatory. Damage due to freezing is not covered by the warranty.
IMPORTANT: Depending on the climatic conditions in your
area you must:
-
Add ethylene glycol with an adequate concentration to
protect the installation up to a temperature of 10 K below
the lowest temperature likely to occur at the installation
site.
-
If the unit is not used for an extended period, it is
recommended to drain it, and as a safety precaution
add ethylene glycol to the heat exchanger, using the
water entering purge valve connection (a purge
connection is available somewhere on the heat
exchanger water box in case the machine is not
perfectly level).
-
At the start of the next season, refill the unit with water
and add an inhibitor.
-
For the installation of auxiliary equipment, the instal-ler
must comply with basic regulations, especially for
minimum and maximum flow rates, which must be
between the values listed in the operating limit table
(application data).
7.5.2 - Optional evaporator frost protection (30XB & XBP)
In cases where it is not possible to apply the recommendations in
paragraph 7.5.1, the units can be equipped with heaters to protect
the evaporator against frost (option 41A or 41B).
7.6 - Operation of two units in master/slave mode
(option 58)
NOTE: This operating mode is not available for 30XB-1700
units.
The control of a master/slave assembly is in the entering water
and does not require any additional sensors (standard configuration).
It can also be located in the leaving water. In this case two
additional sensors must be added on the common piping.
All parameters, required for the master/slave function must be
configured using the Service Configuration menu. All remote
controls of the master/slave assembly (start/stop, set point, load
shedding etc.) are controlled by the unit configured as master and
must only be applied to the master unit.
Each unit controls its own water pump. If there is only one common
pump, in cases with variable flow, isolation valves must be installed
on each unit. They will be activated at the opening and closing by
the control of each heat pump (in this case the valves are controlled
using the dedicated water pump outputs). Refer to the
30XB/30XAS/30XW Touch Pilot control manual for a more detailed
explanation.
7 - WATER CONNECTIONS
Summary of Contents for AquaForce 30XB series
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