comatec AQWL Installations- Und Wartungshandbuch Seite 16

4.3 External Water Circuit
The flow switch and the filter water, although not included in the
supply, must always be fitted such as plant components. Their
installation is mandatory for warranty.
The external hydraulic circuit must ensure the
water flow to the evaporator under any working
or adjustment conditions.
WARNING
The circuit shall be composed by the following elements:
A circulation pump which can ensure the necessary capacity
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and discharge head.
The capacity of the primary hydraulic circuit should not be less
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than 2.4 litres/KW of cooling capacity, in order to prevent the
repeated start-up of the compressor and any damage to it. If
the water capacity in the primary piping of the circuit and in the
evaporator is lower than this value, an insulated storage tank
shall be installed.
A membrane expansion vessel provided with safety valve with
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vent, that must be visible.
The capacity of the expansion vessel must allow
for an expansion of at least 2% of the volume of
the fluid in the circuit (evaporator, piping, user
circuit and standby tank, if any). The expansion
NOTE
vessel needs not be isolated, because no water
can circulate inside it.
4 - Installation (continued)
14
A flow switch, to disable the appliance when the water is not
circulating.
The flow switch must be connected (terminals
1-2) as shown in the wiring diagram of the
"User's Terminal Box" (Paragraph 4.7).
WARNING
To install the flow switch, follow the manufacturer's instructions.
As a general rule, the flow switch shall be mounted on a horizontal
pipe, at a distance from the curves equal to 10 times the diameter
of the pipe and far from valves or other components that are likely
to hinder the water flow upstream of or downstream from the flow
switch.
The bleed valves must be mounted on the highest point of the
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piping.
The stop valves must be mounted on the piping of the water ente-
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ring/leaving the condenser.
The discharge points (provided with plugs, cocks etc.) must be
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arranged in the lowest point of the piping.