Beckhoff AX5000 Series Function Manual

I*t calculation in the AX5000 servo drive
Function description 43
Version: 1.5
9 I*t calculation in the AX5000 servo drive
Note
Reference variables for the I*t calculation:
P-0-0052; P-0-0090; P-0-0091; P-0-0092; P-0-0093
The I*t calculation serves as a safety function in the AX5000 servo drive. The max. permissible overcurrent
time area (I*t
max
) depends on the size of the devices. The servo drive may exceed the rated current for the
calculated time t
max
. The value is then limited to the rated current on expiry of t
max
.
In earlier firmware revisions the max. permissible overcurrent time area could not be used fully. From
firmware v2.06 (build 18) the complete overcurrent time area of the servo drive is now available.
This depends on the peak and rated currents of the different device sizes:
Longer exceedance of the rated current is possible by reducing the peak current. The time (t
max
) is set in
parameter P-0-0052.
Therefore, the following applies to the calculation of the parameter P-0-0052
max
:
The parameters involved are listed in the table below:
P-0-0052 Time limitation for peak current Settable value range: 0 – 65535 ms
P-0-0090 Channel peak current Dependent on the size
P-0-0091 Channel rated current Dependent on the size
P-0-0092 Configured channel peak current Dependent on the application
P-0-0093 Configured channel rated current Dependent on the application
t
max
Max. time for I
peak
Dependent on the size
1)*
1)*
: 7 s for servo drives from the series AX52xx and AX5101 – AX5140.
3 s for servo drives > AX5140 (see electrical data in the AX5000 system manual)
On changing status from Pre-Op to Op, the firmware in the AX5000 checks whether the value set in
parameter P-0-0052 is permissible. A parameter error appears if the value is impermissible.
Special features of parameter P-0-0052:
• P-0-0052 = 0
The current is always provided for the max. possible time (P-0-0052
max
) (max. 1000 s).
• P-0-0052 < P-0-0052
max
The current in parameter P-0-0092 is limited after the set time (1 ms - 65535 ms) to the value of
parameter P-0-0093.
If I
Appl
< P-0-0092, the current is available for a longer period and is limited after t
Appl
.

Beckhoff AX5000 Series Specifications

General

Brand	Beckhoff
Model	AX5000 Series
Category	Servo Drives
Language	English