Video transcription 

Good day to all and welcome to this online course.
In this first video, we will conduct an overview of the principles of breaking electrical circuits.
Produced by Zensol Automation in collaboration with Hydro-Québec,

At the end of this video, the participant will be able to understand the role of grading capacitors

Grading Capacitors.
What is a Grading Capacitor?
What do Grading Capacitors do?

What is a grading capacitor?
Grading capacitors have values on the order of a few picofarads. They are mounted on circuit breakers having several contacts per pole.

What do grading capacitors do?
These capacitors are voltage dividers.
They are mounted in parallel with each contact to spread the voltage over the main contacts of the circuit breaker.
This prevents any contact from being exposed to excess voltage.

Question
Grading capacitors are used to:
A), Reduce current asymmetry during the opening of a circuit breaker.,
B), To avoid exceeding load thresholds in the network.
C), To prevent any contact from being exposed to an overvoltage.,
The correct answer is: C), To prevent any contact from being exposed to an overvoltage (see slide 5).

References
Zensol, Circuit breaker library
Zensol, Circuit breaker timing
Schneider Electric, Cahier technique chronométrage 125.