IOM SYSCREW AIR EVO HSE

15
English
4 - Installation (continued)
4.4 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.
WARNING
The external hydraulic circuit must ensure the
water flow to the evaporator under any working
or adjustment conditions.
The circuit shall be composed by the following elements:
n
A circulation pump which can ensure the necessary capacity
and discharge head.
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The capacity of the primary hydraulic circuit should not be less
than the minimum water volumes shown in the table below, 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.
4
Minimum water contents at normal air conditioning applications
The following formula must be respected
Vmin = Cap * MinCapStep * 28,8 , where
Cap = Nominal Unit Capacity [kW] at conditions of installation
MinCapStep = Minimum unit capacity step [%] shown in Technical Data
Table
If the application is a process cooling type, the minimum system chilled water
volume is generally higher than above recommended.
In this case, please contact your nearest Systemair Sales Office
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A membrane expansion vessel provided with safety valve with
vent, that must be visible.
NOTE
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
vessel needs not be isolated, because no water
can circulate inside it.
A flow switch will stop the unit when the water is not circulating or a
flow rate problem occurs.
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.
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The bleed valves must be mounted on the highest point of the pip-
ing.
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The stop valves must be mounted on the piping of the water en-
tering/leaving the evaporator.
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The drain points (provided with plugs, cocks etc.) must be ar-
ranged in the lowest point of the piping.
WARNING
The flow switch must be connected (terminals
1-2) as shown in the wiring diagram of the
“User’s Terminal Box”.
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
MINIMUM WATER VOLUMES
SYSCREW AIR EVO HSE 380-450-510-590-660 730-810
Recommended system chilled
water volume
4
l 2334 2953
SYSCREW AIR EVO HSE 900-980 1060-1160-1260
Recommended system chilled
water volume
4
l 3608 5017