Trane CXAU - Page 17

Installation- Mechanical
17PKGP-SVX19A-EN
used, they can be used with combination of three-way valves, and the quantity of two-way valve could be 1/3 of total valves
and the quantity of three-way valves could be 2/3 of total valves. Two-way valves should be installed for the FCUs which
are near to the unit, and three-way valves be installed for the FCUs which are far from the unit. If only 2-way valves used, a
di󰀨erential pressure bypass valve should be added between the main pipes of the supply line and return line.
16.
Di󰀨erential pressure bypass valve:
When di󰀨erential pressure bypass valve is used in the system, it must be ensured
that an energy storge water tank should be included in the bypassed short circulation circuit, and the water owrate in the
short circulation circuit must also meet water requirements. When all the FCUs are shut o󰀨 and the two-way valve is shut
o󰀨, the opening degree and bypass owrate of the di󰀨erential pressure bypass valve can meet the water ow requirement.
17.
Connect of multiple units in parallel:
When two or more units are installed in parallel, it is recommended to install a
water collector and distributor on the main return water pipeline to ensure the correct ow distribution of return and supply
water. When units with di󰀨erent capacities are connected in parallel in a water system (not recommended), hydraulic
balancing valves must be installed to ensure the di󰀨erent water owrate for di󰀨erent units met requirement. The units in
parallel should be installed with reversed return water system.
18.
Check valve:
If the unit locate in a lower position of the entire water system, a check valve should be installed on the
outlet of the unit to prevent unit damage from water hammer.
19.
Bypass pipeline:
Bypass pipelines and bypass valve should be installed between the water inlet and outlet of the unit. All
external water supply piping should be thoroughly ushed before the unit connected to the pipelines. It is strictly forbidden
to mix impurities in the water system, otherwise it may cause serious consequences. When ushing, the bypass valve
should be open to bypass the unit and the heat exchanger. After ushing, close the bypass valve and open the drain valves
on the inlet and outlet pipes of the unit.
20.
Drainage:
The lowest point of the water system and other lower part of the equipment that needs to be drained should
be installed with drainage pipes and drainage valves, and be connected to the drain or funnel to facilitate the cleaning and
maintenance of the water system. The schematic diagram of the installation of the drain valve and lter (inlet) is as follows:
21.
Insulation:
The chilled water pipeline should be insulated to prevent the loss of cooling and heating capacity and dripping
water due to condensation on the surface of the pipeline. The water side part of the water system that is in contact with
air should be insulated to prevent condensation and dripping. All the water system components that may be damaged by
freezing in winter should be insulated, and insulation thickness should prevent freezing even at the lowest local ambient
temperature. The water make-up pipelines of the gravity expansion tank or the automatic water supplement valve pipelines
of the pressure expansion tank should be su󰀩ciently insulated or installed in a suitable place indoors to avoid freezing
damage.
Filter
Removal Port
30° 30°
Max Angle 30°
Drainage Valve
Facing Down
22.
Anti-freeze:
When the ambient temperature is low and the unit is not used for a long time, please drain the water inside
the unit to avoid freezing water-side parts. If the water is not drained, DO NOT cut o󰀨 the power supply, and ensure that the
unit can operate normally, so that the unit can automatically operate with antifreeze function. If there is a fault alarm that
cannot be repaired in a short time, then be sure to drain the water. The cooling-only chiller unit must drain the water in the
system in winter to prevent water in the system from freezing components such as the water pipes, water pump and heat
exchanger. Ethylene glycol must be added to cooling-only chiller at low ambient temperature (below 0 °C). Other antifreeze
methods are not recommended, and any damage caused by non-recommended antifreeze methods is not covered
by warranty. For schematic diagram of the installation of antifreeze drain valves, see No. 20 of the pipeline installation
requirements.
23.
Supply water temperature control:
If the unit adopts supply temperature control, there must be a position for installing