It is very frustrating getting your shields disabled because you shot your weapon while getting hit, thus losing roughly 120hp in one seccond, without you realizing it or in the middle of battle. I suggest that devices be disabled in this order when you go over the reactor limit:
Propultion drives (if thrusting has anything to do with going over the limit).
Weapons (if fireing has anything to do with going over the limit).
Shields(as a final resort if the first two catagories have already had thier active devices disabled).
auto-disable
Your ship's computer, being reasonably well-programmed, starts shutting down things you don't 'need'.What reason would there be for drives to be disabled before weapons?
I'd say weapons first. In an emergency low power situation, you'd like to escape, not continue.
what sort of ship design company would let devices be disabled at random?
If your shields are at full hp, then you would want to continue fighting. Most of the situations I accidentally overload my reactor it is because I am fighting, and not running. However, in the end I do think that weapons should be disabled before drives because you usually have two weapons and can deal with one of them going out on you for a moment, while if you are running, you badly need whatever drive your are using. Thus,
Weapons
Drives
Shields (although I can't think of a situation where you would need this)
If your shields are at full hp, then you would want to continue fighting. Most of the situations I accidentally overload my reactor it is because I am fighting, and not running. However, in the end I do think that weapons should be disabled before drives because you usually have two weapons and can deal with one of them going out on you for a moment, while if you are running, you badly need whatever drive your are using. Thus,
Weapons
Drives
Shields (although I can't think of a situation where you would need this)
If I overload my UPS, it shuts the whole lot down, not just the socket responsible for the overload. I'm sure really high-end units are more forgiving though.
Make it a ROM upgrade for the ship's computer, and/or dependent on the tech level of the reactor. Relative to the upgrade level/reactor size, a small overload would result in a sane shutdown of the offending system, a medium overload would result in shutdown of random/multiple high-powered devices, and a large overload would result in full emergency shutdown and ship damage (like a cyberattack or defecive display ROM, maybe even a radiation leak contaminating your armour).
Make it a ROM upgrade for the ship's computer, and/or dependent on the tech level of the reactor. Relative to the upgrade level/reactor size, a small overload would result in a sane shutdown of the offending system, a medium overload would result in shutdown of random/multiple high-powered devices, and a large overload would result in full emergency shutdown and ship damage (like a cyberattack or defecive display ROM, maybe even a radiation leak contaminating your armour).