Daikin WGZ030DW Installation And Maintenance Manual page 6

Water Piping
Manual or automatic air vent valves at the high points of
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the system. Drains should be placed at the lowest points
in the system.
On units with factory-mounted flow switches and where
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flange connections (Victaulic-to-flange adaptors or weld-
on flanges) are to be used, relocating the flow switch is
required to allow for possible future replacement since
the flange will interfere with unscrewing the switch. The
following is recommended, before installing a flange, to
avoid interference 1) Remove the flow switch before and
plug the switch opening in the nozzle. 2) Install the
Victaulic-to-flange adaptor or weld on flange.
3)Relocate the flow switch in the water piping outside
the flange, close enough to it that the wire leads will
reach and the switch can still be unscrewed.
Some means of maintaining adequate system water
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pressure (e.g., expansion tank or regulating valve).
Temperature and pressure indicators located within 3 feet
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(0.9 meters) of the inlet and outlet of the vessels to aid in
unit servicing.
This product is equipped with a copper-brazed 304 series
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stainless steel evaporator plate or a shell and tube
evaporator with carbon steel shell and copper tubes. The
water or other fluid used in these evaporators must be
clean and non-corrosive to the materials used in the
evaporator. The use of non-compatible fluids can void
the equipment warranty. If the compatibility of the fluid
with the evaporator is in question, a professional water
quality consultant should administer the proper testing
and evaluate compatibility
A strainer or some means of removing foreign matter
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from the water before it enters the pump is
recommended. It should be placed far enough upstream
to prevent cavitation at the pump inlet (consult pump
Figure 2: Typical Evaporator Field Water Piping (WGZ030 - WGZ130)
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manufacturer for recommendations). The use of a
strainer will prolong pump life and thus maintain system
performance.
A cleanable perforated basket strainer must also be
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placed in the water line just prior to the inlet of the
evaporator. On Models WGZ 030 to 130, use 0.062-inch
perforations with 41% open area. On WGZ 150 TO 200
use 0.125-inch perforations with 40% open area. This
will aid in preventing foreign material from entering and
decreasing the performance of the evaporator.
If the unit is used as a replacement chiller on a
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previously existing piping system, the system should be
thoroughly flushed prior to unit installation. Regular
water analysis and chemical water treatment on the
evaporator and condenser is recommended immediately
upon equipment start-up.
In the event glycol is added to the water system, as an
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afterthought for freeze protection, recognize that the
refrigerant suction pressure will be lower, cooling
performance less, and water side pressure drop will be
higher. If the percentage of glycol is large, or if
propylene glycol is used instead of ethylene glycol, the
added pressure drop and loss of performance could be
substantial. Reset the freezestat and low leaving water
alarm temperatures. The freezestat is factory set to
default at 36°F (2.2°C). Reset the freezestat setting to
approximately 4° to 5°F (2.3° to 2.8°C) below the
leaving chilled water setpoint temperature. See the
section titled "Glycol Solutions" for additional
information concerning the use of glycol.
A preliminary leak check of the water piping should be
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made before filling the system.
Note: A water flow switch or pressure differential switch
must be mounted in the evaporator outlet water line
to signal that there is water flow before unit will start.
IM 1131-2