[verve_rat]

I actually saw a reasonable explanation for this once: battleshort[1].

That is, sometimes equipment has its fuses bypassed because under battle conditions it is better to have the equipment working in a dangerous state, than not working at all.

So when the ship goes to red alert all the major systems are automatically put in battleshort mode. So a couple of ensigns die rather then the weapons stop working because a fuse blew.

[1]: https://en.m.wikipedia.org/wiki/Battleshort

[Izkata]

Also, Star Trek uses a plasma grid to distribute energy, not simple electrical lines. I think I remember reading somewhere (this may have been fan theory) the sparks flying off are a pressure-release so it doesn't just straight explode.

[hef19898]

That is a very old-school approach so. But it could be an in-uniberse explanation. Overall so, Federation, and Star Trek equipment in general, just seems so incredibly unsafe. Very easy to jury-rigg repairs and modify it so, especially the shield generators!