16
4 - Installation
4.6 Drainage
The drain should allow water to run out naturally, so provide a
downward slope of at least 1°.
CAUTION
During cooling operation, the internal
components may become cold enough to
produce condensation. Install the drain pan and
drain pipette (supplied loose), to remove any
condensate, as detailed in the figure below.
RECOMMENDED WATER COMPOSITION
PH
7,5 - 9
Electrical conductivity
10 - 500
μS/cm
Total hardness
4,5 - 8,5
dH
Temperature
< 60
[°C]
Alkalinity (HCO
3
-
)
70-300
ppm
Alkalinity / Sulphates (HCO
3
-
/ SO
4
2-
)
> 1
ppm
Sulphates (SO
4
2-
)
< 70
ppm
Chlorides (Cl
-
)
< 50
ppm
Free Chlorine
< 0,5
ppm
Phosphates (PO
4
3-
)
< 2
ppm
Ammonia (NH
3
)
< 0,5
ppm
Ammonium Ion (NH
4
+
)
< 2
ppm
Manganese Ion (Mn
2+
)
< 0,05
ppm
Free Carbon Dioxide (CO
2
)
< 5
ppm
Hydrogen Sufide (H
2
S)
< 0,05
ppm
Oxygen Content
< 0,1
ppm
Nitrates (NO
3
-
)
< 100
ppm
Manganese (Mn)
< 0,1
ppm
Iron (Fe)
< 0,2
ppm
Aluminium (Al)
< 0,2
ppm
CAUTION
If the water circuit is to be drained for a time exceeding
one month, the circuit must be fully charged with
nitrogen to prevent any risk of corrosion by differential
venting
Flow switch
To ensure sufficient water flow through the evaporator, it is essential
that a flow switch is installed on the water circuit. The purpose of
the flow switch is to stop the unit in the event of interrupted water
flow, thus protecting the evaporator from freezing. The flow switch
is supplied with a clean contact that must be electrically connected
to the terminals shown in the wiring diagram. The flow switch must
be set up to intervene when the water flow of the evaporator is lower
than the minimum flow declared for the unit in question.
NOTE
The external flow switch must be calibrated in
order to guarantee the flow rate of intervention
shown in the table below
PAW APAC
200
250
Flow rate of intervention (m
3
/h)
2.0
2.5
WARNING
For the unit safety the water flow switch
must be calibrated at the value shown in
the table based on the unit size. Lower flow
rates are not allowed, since they could
cause heat exchanger freezing , irrevocably
damaging the unit. On the other hand, setting
the flow switch inter vention at a higher
flow rate can cause unexpected alarms.
In case the water flow switch trips, before
resetting the device manually, check and solve
the cause: the manufacturer is not responsible
for any damage due to repeated manual resets.
4.5
Water connections
WARNING
The attachments at the water inlet and outlet
shall be connected in compliance with the
instructions which can be found on the labels in
the proximity of the attachments.
Connect the water lines of the plants with the attachments of the unit
whose diameters and positions are shown in Chapter 8.
