Tab.22 PCB connectors
Wire cross section
Stripping length
Tightening torque
solid wire: 0.14 – 4.0 mm² (AWG 26 – 12)
stranded wire: 0.14 – 2.5 mm² (AWG 26 – 14)
stranded wire with ferrule: 0.25 – 2.5 mm² (AWG 24 – 14)
8 mm
0.5 N⋅m
4.7
Water quality and water treatment
The quality of the heating water must comply with the limit values in the
table below. These guidelines must be followed at all times.
Tab.23 Water quality requirements
Heat exchanger material
Aluminium
Heat exchanger type
Sections
Property
Unit
250 - 1300 kW
Degree of acidity (untreated water)
pH
6.5 - 9.0
Degree of acidity (treated water)
pH
6.5 - 9.0
Conductivity at 25°C
μS/cm
≤ 800
Chlorides
mg/l
≤ 150
Sulphates
mg/l
≤ 50
Other components
mg/l
-
Total water hardness (German)
°dH
≤ 8.4
Total water hardness (French)
°fH
≤ 15.0
Total water hardness (English)
°e
≤ 10.5
CaCO3
mmol/l
≤ 1.5
If water treatment is necessary, De Dietrich recommends the following
manufacturers:
Cillit
Fernox
Sentinel
Spirotech
4.8
Process heat application
In process heat applications (for example pasteurisation and drying and
washing processes), the boiler is being used for industrial purposes and
not for central heating. With process heat, the nominal flow (at ΔT 20°C) in
the primary CH circuit must be guaranteed. The flow in the secondary
circuit may vary.
To ensure that this is the case, a flow rate sensor can be fitted, which
locks out the boiler if the flow falls below a specified level (due to a
defective pump or valve, for example).
Important
The service life of the boiler may be reduced if it is used for
process heat applications.
4 Preparation of installation
7762666 - v.02 - 29092020
C 340 / C 640
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