Hitachi SJ700B SERIES, Инструкция по эксплуатации

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Chapter 4 Explanation of Functions
4 - 44
4.2.36 Automatic carrier frequency reduction
- The automatic carrier frequency reduction function automatically
reduces the carrier frequency according to the increase in output current.
- To enable this function, specify "01" for automatic carrier frequency
reduction selection (b089).
Item Function code Range of data Description
Automatic carrier
frequency reduction
b089 00/01 00: invalid, 01: valid
- When the output current increases to 60%, 71%, 83%, or 91% of the rated current, this function reduces
the carrier frequency to 8, 6, 4.5, or 3 kHz, respectively. This function restores the original carrier
frequency when the output current decreases to 5% lower than each reduction start level.
Carrier frequency reduction start level
(Restoration level)
Carrier frequency after
reduction (kHz)
Less than 60% of rated current 10.0
60% of rated current 8.0
71% of rated current 6.0
83% of rated current 4.5
91% of rated current 3.0
- The rate of carrier frequency reduction is 2 kHz per second.
- The maximum limit of carrier frequency change by this function is the value specified for the carrier
frequency setting (b083); the minimum limit is 3 kHz.
Note: If 3 kHz or less frequency has been specified for b083, this function is disabled regardless of the
setting of b089.
10.0kHz
60%
Output current (%)
Carrier frequency
8.0kHz
6.0kHz
4.5kHz
3.0kHz
71% 83% 91%
0 100 50
b089: Automatic carrier frequency
reduction selection
b083: Carrier frequency setting
Related code