C
e3
0b
h3
93
.1
0
0
10
20
30
40
50
0%
20%
40%
60%
80%
100%
120%
B
A
A
Ambient temperature, °C
C
Loadability %
B
Loadability, %
Illustration 9: Derating and the Ambient Temperature
5.1.3 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 (that is, less air removes less heat) and the resistance to electric field (breakdown voltage/distance) decreases.
The full thermal performance of VACON
®
NX AC drives is designed for installation up to 1000 m altitude. The electric insulation is
designed for installations up to 3000 m altitude (check details for different sizes in Technical Data).
Higher installation locations are possible, when obeying the derating guidelines in this chapter.
For permitted maximum altitudes, see
.
Above 1000 m, decrease the limited maximum load current by 1% for each 100 m.
For information on option boards and I/O signals and relay outputs, see VACON
®
NX I/O Boards User Manual.
Example:
For example, at 2500 m altitude, decrease the load current down to 85% of the rated output current (100% – (2500–
1000 m) / 100 m x 1% = 85%).
When using fuses at high altitudes, the cooling effect of the fuse decreases as the density of the atmosphere decreases.
When using fuses above 2000 meters, the continuous rating of the fuse:
Mounting the Unit
Operating Guide | VACON® NX Inverters FI4-FI8
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Summary of Contents for VACON NX FI4
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