Selection of Short Circuit protection device (circuit breaker or fuse upstream of a SS or VFD) including type 1 and 2 coordination

[Anonymous user]

According to the FAQ

https://www.se.com/in/en/faqs/FA329751/

and relevant recommendations (Cahier technique no. 204) it would be helpful to get a “complete” guideline for selection of Short Circuit protection device (circuit breaker or fuse upstream of a SS or VFD) including type 1 and 2 coordination as well. Moreover it would be a good point if there is available the database of maximum permissible let-through energy of “well-known” Soft Starters and Variable Frequency Drivers models (e.g. Altistart 48).

[J_Travostino]

Hello Fotini,

This post has been moved to the Power Foundations forum.

[MathieuGuillot · Accepted solution]

Hello Fotini,

Your question is quite complex and I won't be able to give you a straightforward answer here.

We provide various tools and documentation to select overcurrent protection upstream Variable speed Drive and Soft-starter. Satrting with ATV and ATS catalog.

We also propose online configurator such as EcoStruxure Motor Control Configurator 

Soft starter are covered by IEC/EN 60947-4-2. This standard define test for type 1 and type 2 coordination. type 2 usualty requires ultra rapid fuses that are specified in ATS catalog. Coordination is usually difficult to check just by using energy withstand curves and let thhrough curve and often reuire test and/or simulation.

Variable speed drive are covered by IEC 61800-5-1 including internal short-circuit test. There is no concept of type 1 or type 2 coordination in that case. The withstand capacity with a specified overcurrent protection if necessary is given in VSD technical characteristics. When we provide "type 1" or "type 2" coordination table for VSD, the overcurrent protection is consistent with the VSD withstand, and the type 1 or type 2 performance refer to overcurrent protection and contactor. Again this can not be established without test or complex simulation.

Hope it helps,  Can you explain what is your design pain point behind ?

Regards

[Anonymous user]

Hello Mathieu,

thank you for your reply. To be honest I was excepting that a test procedure is required to confirm the cooperation of the protection device and the motor starter but I am trying to find a more conservative way to define this cooperation in a general approach. To be more specific we are running a project and the client has already decided to work with ABB MCCB and gG fuses in the feeders but he likes more Schneider SS and VFDs. Now he is asking about coordination type 2 confirmation.

[Anonymous user]

Dear @MathieuGuillot,

it seems that @Anonymous user question (... a more conservative way to define this cooperation in a general approach) is similar to what I would like to ask.

Does Schneider carry out tests for each pair/combination of protection device/equipment (starter) to confirm coordination level or test procedure is done only for specific sizes of device/equipment followed by a calculation procedure which gives the result for the other pairs/combinations ? If so, could this calculation procedure be available for sharing ?

If this calculation procedure is not available could you send guidelines for a conservative selection ?

Thank you