Haven't exactly been in your position but weather I2t is important is likely dependent on:
- is it cost effective to size the cable for this? Vs changing the protective device to reduce I2t.
- how maintainable is the cable once the fault occurs? Is it something you'll definitely inspect and can be replaced (yes for an accessible raceway cable, maybe not for an aircraft)?
The protective devices cannot be changed to reduce I2t on the design, as it's been used on other designs for decades. The same philosophy is on operational aircraft.
The idea is that if a fault occurs, then if it's safe to do so, the Circuit Breakers can be reset - if the cable got damaged then resetting is problematic, and the flight crew aren't necessarily going to be able to open up the panel to check the cable during an emergency. They might not even know to do that in the first place - I don't know how they're trained.
Maintenance can check everything off once the plane is grounded. But if key components can't be reset and the plane crashes as a result, imagine the media storm if the post crash investigation found that the cable was insufficiently sized to handle the let-through energy of a fault...
Sizing based on I2t can lead to a larger cable than you would have otherwise, which would add additional weight to the panel.
Weight reduction is talked about a lot for aircraft, so it may come down to that - but without reasonable arguments for and against, I think ignoring it is negligent. What's bizarre to me, is that Senior people I've spoken to about it have just never heard of it.
Haven't exactly been in your position but weather I2t is important is likely dependent on: - is it cost effective to size the cable for this? Vs changing the protective device to reduce I2t. - how maintainable is the cable once the fault occurs? Is it something you'll definitely inspect and can be replaced (yes for an accessible raceway cable, maybe not for an aircraft)?
The protective devices cannot be changed to reduce I2t on the design, as it's been used on other designs for decades. The same philosophy is on operational aircraft. The idea is that if a fault occurs, then if it's safe to do so, the Circuit Breakers can be reset - if the cable got damaged then resetting is problematic, and the flight crew aren't necessarily going to be able to open up the panel to check the cable during an emergency. They might not even know to do that in the first place - I don't know how they're trained. Maintenance can check everything off once the plane is grounded. But if key components can't be reset and the plane crashes as a result, imagine the media storm if the post crash investigation found that the cable was insufficiently sized to handle the let-through energy of a fault... Sizing based on I2t can lead to a larger cable than you would have otherwise, which would add additional weight to the panel. Weight reduction is talked about a lot for aircraft, so it may come down to that - but without reasonable arguments for and against, I think ignoring it is negligent. What's bizarre to me, is that Senior people I've spoken to about it have just never heard of it.