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Determining device designation of rewirable fuses

Farmboy
Table 3.1 of GN6 lists the rated short cct capacity for three BS 3036 device designations (S1A, S2A & S4A). But how do you determine the designation of the device?


On a different note, on an eicr, would you give a C2 to a size that was lower than the PEFC or PSCC at the point of use? I've looked in BPG4 and codebreakers but couldn't see anything relating specifically to breaking capacity (sorry if I've missed it).


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    It is really a measure of the containment of the flying metal when they blow, and is rather a nebulous quantity, as you do not know how well they have been rewired. Generally threy will all open at a higher pssc than rated, what varies is how much of a clean up is needed before it can be rewired and re-energised.  As hot metal can be shot out of the wire threading  holes as well as the inspection well in the ceramic, the higher rated (4000A ) designs have a convoluted path for the hot gas so it does not get out so easily, to protect the finger tips of someone putting a fuse in against a fault The older 1kA ones generally do not..


    If not sure assume 1000A, or fit the cartridge fuse holder versions in the hole instead.
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    It is really a measure of the containment of the flying metal when they blow, and is rather a nebulous quantity, as you do not know how well they have been rewired. Generally threy will all open at a higher pssc than rated, what varies is how much of a clean up is needed before it can be rewired and re-energised.  As hot metal can be shot out of the wire threading  holes as well as the inspection well in the ceramic, the higher rated (4000A ) designs have a convoluted path for the hot gas so it does not get out so easily, to protect the finger tips of someone putting a fuse in against a fault The older 1kA ones generally do not..


    If not sure assume 1000A, or fit the cartridge fuse holder versions in the hole instead.
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