Beckhoff KL2791 Series, Documentation

Page: 19 / 41

Mounting and wiring
KL2791 19 Version: 2.0.0
Attention
The mains voltage should only be supplied via a power feed terminal that is
suitable for 230 V
AC
/ 120 V
AC
!
To supply the mains voltage (230 V
AC
/ 120 V
AC
) for the power contacts, it is essential to use
a power feed terminal that is designed for 230 V
AC
/ 120 V
AC
(e.g.: KL9150, KL9160,
KL9250, KL9260)!
Bus Couplers, Bus Terminal controllers and power feed terminals for 24 V are not suitable
for the supply of mains voltage into the power contacts!
They are specifically designed for voltages up to 24 V and would be destroyed if
230 V
AC
/ 120 V
AC
was applied to their power contacts!
Note
Separation terminal
If 24 V and 230 V
AC
/ 120 V
AC
are to be used on the power contacts in a Bus Terminal block,
the KL9080 separation terminal can be used in order to clearly separate the potential
blocks visually from each other.
Short-circuit limitation
The speed controller terminals feature short-circuit limitation. The current is limited to approx. 10 to 15 A.
Normally triggering of the fuse is therefore prevented.
The short circuit current flows for less than 0.5 ms and is switched on automatically. After a short circuit was
detected the KL2791 tries to switch the system on again and tests the line with a low voltage. Once the short
circuit has been rectified, the speed controller terminal returns to the previous control value.
Short circuits on the line should always be avoided and never be induced deliberately! The short circuit puts
the components in the speed controller terminal under stress. A high number of short circuits reduces the
service life of the speed controller terminal!
Fuses
The speed controller terminal can be protected with fuses up to 10 A.
The speed controller terminal protects itself from damage due to short circuit or overload. This built-in
protection is triggered in the event of a short circuit on the connecting line between the speed controller
terminal and the load.
Attention
Use overload protection!
However, overload protection must still be provided. The fine-wire fuse often used in de-
vices with transformers must not be bridged or changed in its value. This could lead to
overheating of the transformer.