These videos, produced by Zensol Automation Inc., discuss fundamental to advanced concepts and explore the different principles of electrical circuit operation.

Video 1: Basic principles of electrical circuit breaking

This video explains what happens when you break a circuit in HV and how to prevent the arc from reestablishing itself in different insulating media.

Breaking an electrical distribution or transport network permits the isolation of part of the network from the rest of it. In the high voltage field, separating the contacts is not enough to break the current instantly.
When the contacts separate, the current continues to flow and a temporary electric arc forms between the moving and fixed contacts. To extinguish the arc, the arcing current must become zero and stay at zero. By varying the opening speed and the distance between contacts, the power and duration of the electric arc are greatly affected.
Sufficient contact spacing for certain insulating media helps a lot in cooling and extinguishing the arc.

Length: 9mn 43s
Topic : Electrical circuit breaking principles

Video 2: Auxiliary contacts

The pre-insertion contacts and the signal contacts are both commonly called auxiliary contacts and it is important to know the difference between them. This video describes the difference between the two types of auxiliary contacts and their respective roles.

Length: 5mn 09s
Topic : Electrical circuit breaking principles

Video 3: ICOS synchronous command

This video describes the principle of ICOS synchronous command and when it should be used. This command is used only during controlled open and close operations, which means during intentional operations. It is also used on other devices such as shunt coils, capacitor banks and some transformers at 315 kV and 735 kV. ICOS synchronous command is an interesting alternative to eliminating certain pre-insertion contacts.

Length: 5mn 01s
Topic : Electrical circuit breaking principles

Video 4: Grading Capacitors

This video explains what a grading capacitor is and when it should be used. Grading capacitors are mounted on the breaker in order to prevent any contact from being exposed to excess voltage.

Length: 2mn 08s
Topic : Electrical circuit breaking principles

Video 5: Circuit breaker timing principles

This video explains the timing principles of the circuit-breaker and when timing is done: High voltage part and control part. Checking the mechanical operating times of circuit breakers is essential.  These times are a kind of operating signature.
Not respecting the required timing specifications may have grave consequences on the equipment, including its destruction.

Length: 13mn 53s
Topic : Circuit breaker timing principles

Video 6: Locating cable connection points

This video shows how to choose a standard or detailed test plan and then how to connect the cables according to the chosen test plan.

Length: 4mn 19s
Topic : Circuit breaker timing principles

Video 7: Location of displacement transducers and installation procedures

This video talks about the differents types of displacement transducers, examples of graphs of displacement transducers installation on some circuit breakers and some recommendations for transducers’ installation. Some transducers are of the analog type, such as the resistive transducers, either linear or rotary. Others are of the digital type, such as optical encoders. To be used, these transducers must be mounted on mechanical adapters to capture and record the motion of the breaker’s moving contacts.
The breaker mechanism’s motion gives a good idea of what type of transducer and mechanical adapter to use.

Length: 4mn 46s
Topic : Circuit breaker timing principles