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Freeze protection: The freezing point of the coolant is determined by the concentration of
heat transfer fluid in the mixture.
The higher the concentration of heat transfer fluid, the higher the viscosity of the coolant.
This results in a higher pressure loss in the system. See
The nominal current ratings of drive system modules apply to an Antifrogen® L / water
solution of 25/75% (volume). With the Antifrogen® L concentration between 25% and 50%,
the drive output current must be derated by 1/3 percentage point per 1 p.p. increase in
Antifrogen® L concentration. The drawing below shows the derating factor (k) in relation to
Antifrogen® L concentration.
k
1.00
0.95
0.90
25%
30%
35%
Incoming coolant temperature:
• 0...40 °C (32...104 °F): no drive output current derating required
• 40...45 °C (104...113 °F): drive output current must be derated by 2 percentage points
per 1 °C (1.8 °F) temperature increase, as shown by curve (a).
• 45...50 °C (113...122 °F):
• If components with a maximum operating temperature of 55 °C (131 °F) are installed
in the same space as the drive modules, drive output current must be derated by 6
percentage points per 1 °C (1.8 °F) temperature increase, as shown by curve (c).
• If there are no components with a maximum operating temperature of 55 °C (131 °F)
installed in the same space as the drive modules, drive output current must be derated
by 2 percentage points per 1 °C (1.8 °F) temperature increase, as shown by curve
(b).
The drawing below shows the derating factor (k) in relation to coolant temperature.
k
1.00
(a)
0.90
0.80
0.70
0.60
+40 °C
+45 °C
+104 °F
+113 °F
Condensation is not allowed. The minimum coolant temperature to avoid condensation (at
an atmospheric pressure of 1 bar) is shown below as a function of relative humidity (RH)
and ambient temperature (T
40%
45%
50% Antifrogen® L concentration
(b)
(c)
+50 °C
T
+122 °F
).
air
Internal cooling circuit 105
Pressure limits (page
106).
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