Danfoss VACON NX Commissioning And Maintenance Manual page 34

3 4 VACON
Exampl e 1, high ambient temper atur e
If the customer and/or end-user have a high ambient temperature, 35C, at the main drive that
would require the primary circuit temperature to be equal or higher than 35C. This would normally
require a load reduction of the main drive. If the maximum relative humidity at the main drive is
known, the dew-point chart (Chart 5.3-1) can be used to determine a more optimized temperature
for the primary circuit.
Ambient temperature = 35C
Maximum relative humidity = 60%
Acc. to chart 3.3-1Dew point is @ 26C
It is recommended to use a 2C safety margin. Therefore the primary circuit temperature should in
this case be set to 28C (26C +2C). In this case no reduction of load in the main drive is needed,
even if the ambient temperature is high, due to a rather low maximum relative humidity.
Figure 5.3-3 Example 1
The secondary circuit maximum temperature should always be 5C lower that the primary circuit
temperature to ensure a good thermal load transfer between the two circuits. In example 1 this
means that the secondary circuit should be between +5...+23C during operation. The 3-way valve in
the secondary circuit will then keep the primary circuit temperature at 28C regardless of the main
drive load.
Exampl e 2, high ambient r el ative humidity
If the customer and/or end-user have a high ambient temperature, 40C, at the main drives that
would require the primary circuit temperature to be equal or higher than 40C. This would normally
require a significant load reduction of the main drive. If the maximum relative humidity at the main
drive is known, the dew-point chart can be used to determine a more optimized temperature for the
primary circuit.
Ambient temperature = 40C
Maximum relative humidity = 80%
Acc. to chart 3.3-1Dew point is @ 36C
5
Maximum ambient temperature +35°C
Maximum ambient relative humidity 60%
VACON LIQUID COOLED NX DRIVE
Primary circuit minimum +28°C (26°C+2°C)
Local contacts: http:/ / dr ives.danfoss.com/ danfoss- dr ives/ local - contacts/
COMMI SSI ONI NG
HXL120
Secondary circuit
maximum +23°C
(28°C-5°C)