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

[2]

Braking resistance

[3]

Internal temperature switch or external overload relay

[4]

PLC

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

Flatpack resistors have internal thermal protection (non-replaceable fuse), which interrupts the circuit in the event of an overload and protects against consequential damage. No additional thermal protection is required.
Observe the project planning specifications and the documented assignments of inverter and braking resistor.
Additional information