24 vacon
technical data
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
4
4.4.1
Ambient temperature
The power rating of the Active Front End unit is valid for an ambient temperature of 40 ºC (104 °F). If
the device is to be used in higher ambient temperatures, its power rating must be subjected to
derating. The derating coefficient from 40 °C to 50 °C, use derating factor 1.5 %/1 °C, and from 50 °C
to 55 °C, use derating factor 2.5 %/1 °C, for ambient temperatures not exceeding 55 °C (131 °F). The
reduced power is calculated using the formula:
P
de
= P
n
*((100% - (t - 40 ºC)*X)/100)
Pn = nominal power of the unit
t = ambient temperature
x = derating coefficient
C
11167A_00
0
10
20
30
40
50
60
0%
20%
40%
60%
80%
100%
120%
B
A
A
Ambient temperature,
°C
B
Loadability, %
C
Loadability %
Figure 4
-
4. Derating as the ambient temperature
4.4.2
High altitude installation
The density of air decreases when the altitude increases and the pressure decreases. When the air
density decreases, the thermal capacity decreases (i.e. less air removes less heat) and the
resistance to electric field (breakdown voltage / distance) decreases.
