Excerpted from a post to Baen's Bar Snerker's Only dated December 29, 2005:

Hyper generator modes of operation

    Basically, just as a ship's mass/dimensions affect its acceleration rate, they also affect the speed with which it can make hyper translations. That is, a smaller, "handier" ship can cycle its hyper generator much more rapidly than a great big hairy superdreadnought, and military-grade hyper generators can cycle faster than civilian-grade hyper generators.

    There are four basic levels of readiness for a hyper generator:

    (1) Powered Down. This one, I think, is probably fairly self-explanatory.

    (2) Routine Readiness. In this stage of readiness, the generator's basic readiness checks have been completed, there's a minimal power load on it, but its capacitors are not fully charged, and various safety interlocks are still closed to preventâ?¦ unfortunate accidents.

    (3) Stand-By Readiness. In this stage of readiness, the capacitors are fully charged, the interlocks have been disengaged, and the engineer is ready to press the "go" button. However, even after the button is pressed, there is a minimum cycle time while the generator spins its field up to translation capability.

    [ David seemed to have trouble counting the day he composed this, so I'll take the liberty of including the fourth readiness state for him:

    (4) Sustaining. Running and in hyperspace. -Ed ]

    It takes longer to go from Powered Down to Routine than from Routine to Stand-By. Basically, without getting into the detailed numbers (which scale with the tonnage of the ship, from a minimum cycle time of 30 seconds for even a dispatch boat), an 8,000,000-ton superdreadnought requires 4 minutes to go from Stand-By to actual translation. That is, the absolute minimum time for that ship to translate into hyper would be 240 seconds. To go from Powered Down to Translation, the same ship would require 32 minutes.


   



Excerpted from a post to DAVIDWEBER.NET dated June 27, 2011:

    The generator has to be online and running at what I think of as "full" or "operational" readiness for a ship to enter or leave hyper space or to change hyper bands. It is also on in sustained operation the entire time the ship is in hyper, but this is not necessary to keep it in hyper; it is operated in that fashion in order to maintain hyper maneuverability (the ability to transition from band to band in routine navigation (and to evade potential threats --- natural or manmade --- by band-hopping. Missiles don't care about threats and if LACs were being used in an escort role, they would/could be covered by the merchies' hyper fields for "in close" transits or band-hopping and would be able to avoid just about any conceivable natural threat while dealing with the manmade threat which had required their deployment in the first place. (Before anyone objects to the previous sentence, "avoid" does not apply to LACs which find themselves in a grav wave, but since only an idiot would launch them there in the first place, I think we can agree to ignore that particular possibility.) From a starship's perspective, an operating hyper generator affords several advantages which range from highly useful to potentially vital where grav waves and some of the other hazards of hyper-navigation are concerned, which is why it's kept online… and why it defaults to n-space whenever the ships computers know a "safe" n-space destination woould be in reasonable reach cruising at a high-percentage of light speed.