Derating Curves - Hitachi WJ200 Series Instruction Manual

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Derating Curves

The maximum available inverter current output is limited by the carrier frequency and
ambient temperature.. Choosing a higher carrier frequency tends to decrease audible
noise, but it also increases the internal heating of the inverter, thus decreasing
(derating) the maximum current output capability. Ambient temperature is the
temperature just outside the inverter housing⎯such as inside the control cabinet
where the inverter is mounted. A higher ambient temperature decreases (derates) the
inverter's maximum current output capacity.
Individual mounting
An inverter may be mounted individually
in an enclosure or side-by-side with other
Enclosure
inverter(s) as shown below. Side-by-side
mounting causes greater derating than
mounting inverters separately. Graphs for
either mounting methods are included in
this section. Refer to "Ensure Adequate
Ventilation" on page 2-10 for minimum
clearance dimensions for both mounting
configurations.
Side-by-side mounting
Enclosure