User`s manual

94 • Vacon apfiff09 marine
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6
7.2.5 Prohibited frequencies
In some systems it may be necessary to avoid certain frequencies because of mechanical resonance
problems. With these parameters it is possible to set limits for the prohibited frequency region and
ramp rate factor to use when frequency is going above this area. When the input reference is
increased the internal reference is kept at the low limit until the input reference is above the high
limit.
P2.2.10.1 Prohibit frequency area 1; Low limit ID509
P2.2.10.2 Prohibit frequency area 1; High limit ID510
Range definition where a different ramp time is used.
Used
Speed Reference [RPM]
Requested Speed Reference
[RPM]
Low Lim
High Lim
P2.2.10.3 Ramp time factor for prohibited range ID518
Multiplier of the currently selected ramp time between prohibit frequency limits.
Time [s]
Speed [RPM]
Low Lim
High Lim
Ramp Time
Factor = 2,5
Ramp Time
Factor = 0,3
Figure 7-1. Ramp rate scaling between prohibit frequencies