Required Derating Toward Altitude - Hitachi SJ100 SERIES Service Manual

4-2. Required derating toward altitude

100%
90%
80%
70%
Example of calculation
SJ100-007NFE (4 Amps) is installed at 2000m of altitude and 16kHz of carrier frequency.
Required derating of output frequency of this case will be as follows.
4 [Amps] * 90% * 95% = 3.4 [Amps]
<Note 1> When the top cover is removed for the high ambient temperature, inverter should be installed
in an enclosure of IP 4* (see EN60529) to comply with LVD directive.
<Note 2> If class B of EMC directive is required, carrier frequency must be set to 5kHz.
1000 2000
Altitude [m]
Carrier frequency derating
Altitude frequency derating
4-4/E
3000 4000