Protecting the braking resistors from thermal overload

The braking resistors can be protected against overload and overtemperature with an integrated temperature switch for BW..-T braking resistors and with an external thermal overload relay for BW.. braking resistors.

Circuit 1
with integrated temperature switch

Circuit 1
with external overload relay

[1]

Line contactor

[4]

PLC

[2]

Braking resistor

[5]

Inverter

[3]

Internal temperature switch or overload relay

For the sake of clarity, only the integrated temperature switch is visualized in the following graphics. Implementation with an external thermal overload relay is carried out in the same way.

INFORMATION

A PTC braking resistor becomes highly resistive in the event of an overload.

INFORMATION

Flatpack resistors have internal thermal protection (fuse cannot be replaced) that interrupts the current circuit in the event of overload. The configuration guidelines and the documented assignments of the drive inverter and braking resistor must be adhered to.
Additional information