WEG CFW-11W G2 RB Series User Manual page 38

The water used in the coolant must meet the specifications of
contain any organic sediments or active chemical agents. The coolant is composed of demineralized water,
corrosion inhibitor and ethylene glycol.
ATTENTION!
Do not use sea or tap water in the coolant.
The specifications of the inverter output current informed in
coolant temperature between 10 and 45 °C (50 ºF to 113 ºF), and the composition according to
page 3-19.
Table 3.11: Coolant composition for temperature from 10 to 45 °C (50 ºF to 113 ºF)
For the inverter operation at temperatures below 10 °C (50 ºF), the concentration of ethylene glycol in the coolant
must be increased. The increase of the percentage of ethylene glycol reduces the coolant specific heat and the
system heat exchange capacity. Therefore, if the inverter operates with a quantity of ethylene glycol above the
specification of Table 3.11 on page 3-19
derated. As the ethylene glycol concentration is normally increased to reduce the coolant freezing point, the coolant
temperature reduction can compensate the current derating.
percentage of the output current as a function of the ethylene glycol concentration and the coolant temperature.
Table 3.12: Maximum percentage of the output current as a function of the ethylene glycol concentration and the coolant temperature
ATTENTION!
To prevent corrosion, always add 1 % of the inhibitor CorteC VpCI-649 to the coolant.
Condensation may occur when the incoming water temperature is significantly lower than the ambient temperature.
The water temperature to avoid condensation varies according to the air relative humidity and ambient temperature.
The temperature at which the water vapor contained in the air turns into liquid as small water drops is known as
"dew point".
Table 3.10: Water specification
Characteristic Unit
pH
Hardness °dH
Conductivity µS/cm
Chlorine mg/l
Iron mg/l
Maximum particle
µm
size
Component
Demineralized water
Ethylene glycol
Inhibitor CorteC VpCI-649
and coolant temperature of 45 °C (113 ºF), the output current must be
Glycol Concentration
10 % 20 %
37 °C 100 % 100 %
39 °C 100 % 100 %
41 °C 100 % 100 %
43 °C 100 % 100 %
45 °C 100 % 98 %
47 °C
98 % 96 %
49 °C 96 % 94 %
51 °C 94 % 92 %
53 °C 92 % 90 %
55 °C 90 % 88 %
Installation and Connection
Table 3.10 on page 3-19. The coolant must not
Value
6 - 8
< 10
< 10
< 10
< 0.1
< 300
Chapter 8 TECHNICAL DATA on page 8-1
Proportion
88.5 %
10 %
1.5 %
Table 3.12 on page 3-19
30 % 40 % 50 %
100 % 100 % 100 %
100 % 100 % 98 %
100% 98 % 96 %
98 % 96 % 94 %
96 % 94 % 92 %
94 % 92 % 90 %
92 % 90 % 88 %
90 % 88 % 86 %
88 % 86 % 84 %
86 % 84 % 82 %
are for a
Table 3.11 on
shows the maximum
CFW-11MW G2 RB | 3-19
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