In APM Low harmonic ATV9B0XXX is there any possibility to go up to 55°C.

, it is possible but we have to take two points into account and respect it absolutely:

• External 24VDC supply have to be in accordance of the data written in the APM documentation, with respect of the voltage tolerance. Otherwise we can faced on problem on electronics, as overheating or cause malfunction to the drive (see in attachment extract from the Installation manual, Power Supplies specif.).
• Cubicle cooling needs to be done in accordance with the integration manual. Otherwise, it can lead to an overheating and damage of the drive (see in attachment extract from the installation manual, Cooling specif.).

The derating to apply for an ambient temperature at 55°C is basically I/In = 70%. The rule is quite restrictive but in that way we will not have any issue on power cycle.
In an other way, we can take into account the fact that the derating is apply to one brick, following it nominal current itself. By consequence, following the drive rating, bricks are not fully loaded and we can win some margin by applying this rule for brick maximum current and compare to needed power. Which mean in practical, less derating from drive point of view. See attached image

Released for: Schneider Electric India