LFP Available Short Circuit Current

[CaptainRivet]

Originally Posted by tanglewood

No, I think this is PRECISELY what the AIC rating is. It's the maximum current at which the fuse can open, and STAY open. I think the discussion has been going in circles for nearly a month because you are working to an incorrect definition of what AIC means/is.

Please show me where it stands that AIC means disconnect AND STAY disconnected at AIC and for how for how long?

Then please explain also how can you have an AIC of 20kA rating staying disonnected with 7mm gap between the 2 metal parts (thats what a 400A Class T has) when physically around 8-10kA is already enough to arc up to 3cm when this 8-10kA is present for more then 3sec ionizing the air. Thats pure physics, nothing else .That this is the case you can see at the Winston test how the current of a shortened cell is builing up.

[tanglewood]

Originally Posted by CaptainRivet

Please show me where it stands that AIC means disconnect AND STAY disconnected at AIC and for how for how long?

Then please explain also how can you have an AIC of 20kA rating staying disonnected with 7mm gap between the 2 metal parts (thats what a 400A Class T has) when physically around 8-10kA is already enough to arc up to 3cm when this 8-10kA is present for more then 3sec ionizing the air. Thats pure physics, nothing else .That this is the case you can see at the Winston test how the current of a shortened cell is builing up.

This is from Eaton, but Schneider and others say the same thing:


AIC (kAIC) applies to protective interrupting devices such as circuit breakers and fuses. The unit of measure for AIC is Amps RMS Symmetrical. This figure, which is typically in range of 5000 to 200,000 amps, describes the maximum fault current that the protective device can clear safely, without welding closed or causing damage to equipment or personnel.


If current continues to flow, then I think it's pretty clear that it hasn't cleared the fault.


As for arcing, air gaps, and other construction properties that allow these to work, I don't know. But if there is some other standardized parameter that you are talking about, what is it?

[s/v Jedi]

Originally Posted by CaptainRivet

Please show me where it stands that AIC means disconnect AND STAY disconnected at AIC and for how for how long?

Then please explain also how can you have an AIC of 20kA rating staying disonnected with 7mm gap between the 2 metal parts (thats what a 400A Class T has) when physically around 8-10kA is already enough to arc up to 3cm when this 8-10kA is present for more then 3sec ionizing the air. Thats pure physics, nothing else .That this is the case you can see at the Winston test how the current of a shortened cell is builing up.

It is physically impossible to have a “8-10kA current present” when there is no circuit it flows through. A current is there or not there; it can not build up to make a jump.

You only have a current when a circuit is completed. To jump a gap, you need voltage.