1. Modelling Internal Arc
Question 1-2
Modelling Internal Arc

2. Is modelling sufficient to insure Internal Arc class compliance ?
Abcd Special report Question 1-2
Is modelling sufficient to insure Internal Arc class compliance ?
we are performing both calculations and tests for more than 20 years
our answer based on this experience is:  not sufficient enough !
the better solution is calculations verified and backed by tests

3. Abcd Special report Question 1-2
- modelling helps during preliminary design phase
- it also helps during test phase
- it helps for extrapolation in similar design
- it can be utilised for building construction and environment
 but calculation can only be useful if it has been verified and coordinated with test results in real practice

4. What is the impact of this IA class in term of design?
Abcd Special report Question 1-2
What is the impact of this IA class in term of design?
our answer based on the experiences gathered from different countries and manufacturers integrated in Alstom T&D is:  yes , there is an impact !
first it is necessary to design to avoid any arc fault

5. Abcd Special report Question 1-2
second, it is necessary to design to fulfill the 5 criteria (IEC ) , i.e., : - manage pressure , manage thermal effects
since arc fault withstand is a standard requirement , this must be taken into account from the very beginning of the design to be a basic characteristic of product
as a manufacturer we fully integrate this in our design to ensure safety to users.

6. Abcd Special report Question 1-2
Are there any experience carried out with active arc protection system ?
we have experience within Alstom T&D with different kinds of active arc protection systems such as luminary detection, or micro contacts on flaps etc.,

7. Abcd Special report Question 1-2
it helps to reduce the fault duration significantly and consequently to reduce damages on equipment
it does not fully replace the passive withstand of the cubicle which ensures safety to people
arc fault withstand of a cubicle can be compared with an airbag; « have it in standard, but Do not make use of it as far as possible ! »