Summary
The specification for " i^2 t " has units of Amps squared times seconds. Th ere is a spec to test fuse blowing performance which uses i squared t. In t he spec, that "iit" uses a current i in a fuse for a time t of 8ms. The err or is that Littlefuse calls (i^2 t) energy. But it is not Joules, it is Jou le seconds.
iit = Joule Seconds, not energy as Littlefuse claims.
Details
Joules = distance*force = meters*kilogram*meters/second^2
Ampere = Coulomb/second
Ampere^2 = Coulomb^2 / second^2
iit = Coulomb^2 / second
The ERROR is there. The denominator has second, but energy has second^2 in the denominator. I call upon Littlefuse to notify all of its distribution c orporations to correct their documentation. It is not energy, Joule Seconds is Action.
Joule Seconds = angular momentum, and was called Action by Planck.
Joule = energy = meters*kilogram*meters/second^2
iit = Coulomb^2 / second
Reference Specs:
Littlefuse Error Spec: "This energy is described as nominal melting I^2 t a nd is expressed as ?Ampere Squared Seconds? (A^2 Sec.). A p ulse of current is applied to the fuse, and a time measurement is taken for melting to occur."
Mersen: "AMPERE SQUARED SECONDS, I^2 t It is the measure of heat energy dev eloped within a circuit during the fuse's clearing. It can be expressed as "melting I^2 t", "arcing I^2 t" or the sum of them as "Clearing I^2 t ". "I " stands for effective let-through current(RMS), which is squared, and "t" stands for time of opening, in seconds. The use of I^2 t values to determin e proper fuse typing/ rating is only valid under adiabatic conditions, wher e there is no external heat transfer."
Alan Folmsbee, MSEE