General Purpose MV Fuses minimum current

[corvalan]

The standard for MV General Purpose fuses establishes that the fuse should not oprate on currents that will make. The fuse open in more than one hour. The chalange i have is how to know this minimum allowable current.

The manufacturrer TCC’s plot the general purpose curve up to 300s or up to 1,000s not up to 3,600.s 91 hour). So i cannot know the minimum callowable current from the TCC. So two questios?

Do general purpose fuse manufacturers publush this one hour minimum current? If yes, can you refer me to a specific case?

If not, how can i get this current?

Thanks.

 

[bacon4life]

The exact amount of current to trip in 1 hour is highly dependent on the ambient temperature and wind conditions. Here are a few links that may give you an idea of the factors that go into loading for moderate durations. Also, be aware that repeatedly loading the fuse to just below the melt point may damage the fuse.

http://www.sandc.com/globalassets/s...nts---all-documents/data-bulletin-350-190.pdf

http://www.sandc.com/globalassets/s...nts---all-documents/data-bulletin-350-195.pdf

http://www.sandc.com/globalassets/s...nts---all-documents/data-bulletin-350-200.pdf

http://www.sandc.com/en/products--services/products/positrol-fuse-links/

- product literature