3 current limit values (imax limit values), Current limit values (imax limit values), Configuration – Lenze 8200 Frequency inverters User Manual

Page 154: 3 current limit values (i, Limit values)

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Configuration

8200SHB0199

7-17

7.5.3

Current limit values (I

max

limit values)

Code

Name

Possible settings

IMPORTANT

Lenze

Choice

Info

C022 I

max

limit

(motor mode)

150

30

{1 %}

150

C023 I

max

limit

(generator mode)

80

30

{1 %}

110

822X/824X

80

30

{1 %}

150 as of software

1.6 and HVAC

Function

The controllers are equipped with a current-limit control which determines the dynamic response
under load. The measured load is compared with the limit values set under C022 for motor load and
under C023 for generator load. If the current limits are exceeded, the controller changes its
dynamic behaviour.

Series “HVAC”:

-

C023 = 30 %
- Current limit controller for generator mode not active (only for applications with special

machines running at high field frequencies at the same time).

- Only possible with control mode V/f-characteristic control (C014 = -2-) (see chapter 7.5.5).

-

C023 = 30 % or C023 = 149 %
- Earth-fault detection not active.

Adjustment

Set the acceleration and deceleration times so that the drive can follow the speed profile without
reaching I

max

.

Controller behaviour when
reaching the limit value

-

During acceleration:
- Increase of the acceleration ramp

-

During deceleration:
- Increase of the deceleration ramp

-

With increasing load and constant speed:
- When reaching the motor-current limit value:

Decrease of the field frequency to
10 Hz at 820X
0 Hz at 821X/822X/824X.

- When reaching the generator-current limit value:

Increase of the field frequency to the max. frequency (C011).

- Stop the field-frequency change if the load falls below the limit value.

Important

821X/822X/824X

-

A correct current control in the generator mode is possible only with a connected brake unit or in
the DC-bus connection with energy exchange.

-

For operation with chopper frequencies > 8 kHz, the current limit values should be set to the
currents ”I

max

for 60 s” indicated in the rated data (see chapter 3.4).

(Derating at higher chopper frequencies)

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