Owner manual

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Voltage boost V

min

In the low speed range, the obtained torque is determined largely

by the set voltage boost. If you set V

min

(C016), make sure that the

motor cannot be destroyed by overheat.

Experience tells that self-ventilated standard asynchronous

machines of insulation class B can be operated in a frequency

range up to 25Hz only for a short time with rated current. Therefore

proceed as follows:

• The motor should be operated in idle running.

• Provide a set-value of 4 to 5 Hz.

• The voltage boost should be set such that

− the motor current (C054) does not exceed the rated value

for short-time operation in the low frequency range.

− the motor current (C054) does not exceed 80 % of its rated

value for permanent operation in the low frequency range.

For exact data of the permissible motor current please refer to the

motor manufacturer.

Forced-ventilated machines can be permanently operated with

rated current even in the low frequency range.

Code Parameter Meaning Acceptance

C014 -0-

-1-

linear characteristic

square characteristic

[SH + PRG]

C015 50.0Hz

7.5...960Hz

V/f rated frequency ON-LINE

C016 0.0%

0.0...40%

voltage boost ON-LINE