B16 vs C16 Fuses: Comparing Overload & Short Circuit Performance in Automatic Fuses (Esy)

Dear fellow electricians, I have a question related to fuses B16 and C16. I would like to know which will work first in overload and short circuit. I know that the fuses B16 are faster than C16. C16 are used in the protection of motors. But I heard that there are places on the characteristics with B16 and C16, they will work simultaneously when shorted. If I am wrong, please correct me. Thank you for your help. And I am talking about automatic fuses, they are commonly called esy.

Hello. It is a bit complicated with these essays, but I will try to explain it to you as simply as I can. There are no faster and slower words, but there is a time characteristic of the current. It is about electric shock protection consisting in automatic quick disconnection, and so for C-shaped pipes with B characteristic, multiplicity of 5 is assumed, i.e. for B16 5x16A it is 80A, such a current must flow within 0.2s for the protection to be fulfilled. For the C characteristic, multiplicity of 10 is assumed, i.e. for C16 160A, C20 200A, etc. For the D characteristic, multiplicity of 20 is assumed, i.e. for D10 200A. When selecting the protections, it is best to use a short circuit loop meter. Using esy it is difficult to obtain security selectivity, only with long lines between security it is possible. As for the overload, the multiplication factor of 1.45 is assumed for all characteristics and is selected for the Idd of the cable. Best regards.

The shortest way - in the event of an overload, the first will operate B16 rather than C16 (an example is a motor start-up, where during the start-up the inrush current exceeds the protection activation current several times), in the event of a short circuit, both
a colleague sq9jjh with selectivity is right, with a metallic short circuit, B16 B25 and C40 can work together

And even shorter: the greater the currents, the closer the characteristics are to each other.



This happens until the order of operation becomes random and may depend more on the mechanical inertia than on the characteristics, and if the current reaches a sufficiently large value, the protection will weld rather than shut down - there is such a thing as a maximum current that the protection cuts out.

Thanks for the answers. So you can say that if he uses fuses B16 and C16, they can both trip at the same time in the event of a short circuit? So there is no selectivity.

Selectivity is there, but depends on the short-circuit loop resistance and the transformer power :D

One of your colleagues already wrote that you can be sure of selectivity in your specific conditions by making measurements and performing the necessary calculations.

kisses

Hello
To obtain selectivity for S B16A circuit breakers, the preceding protection would have to be 25A fuse links, i.e. 2 degrees higher value. S303 C25A being a pre-meter protection and the protection of this luminaire S301B10A did not work and did not turn off despite the fact that it was functional. Such situations may occur at a small distance from the transformer station and thus a high short-circuit current. selectivity.
best regards