The ObF [Over Braking Fault] appears when the drive is in a run state and voltage on a DC bus is over the OBF level that represents 825V DC (a N4 version), When there is a voltage dip, the drive goes in the deceleration mode & if the motor is connect to high inertia load, it works in a Generator mode & trip on OBF fault.
Most usual cases of OBF fault are:
- Motor works in a Generator mode
- The braking is too dynamic
Both cases cause too much energy to dissipate in DC bus.
To avoid that:
- Increase the DEC [Deceleration ramp] as much as the application allows;
- Activate the brA[Dec ramp adapt.] parameter, IF APPLICATION ALLOWS. Not possible if the [BRAKE LOGIC CONTROL] function is active;
- Use a braking resistor
Most usual cases of OBF fault are:
- Motor works in a Generator mode
- The braking is too dynamic
Both cases cause too much energy to dissipate in DC bus.
To avoid that:
- Increase the DEC [Deceleration ramp] as much as the application allows;
- Activate the brA[Dec ramp adapt.] parameter, IF APPLICATION ALLOWS. Not possible if the [BRAKE LOGIC CONTROL] function is active;
- Use a braking resistor
Released for: Schneider Electric India


Need help?
Product Selector
Quickly and easily find the right products and accessories for your applications.
Get a Quote
Start your sales enquiry online and an expert will connect with you.
Where to buy?
Easily find the nearest Schneider Electric distributor in your location.
Help Centre
Find support resources for all your needs, in one place.