Hi, Yep you can take this info as gospel. The reason you probably havn't heard of it is that higher end servo drives ie: the expensive ones the big boys use, have a thing called a dump resistor built in so when the drive is decelerating the excess energy is dumped across the resistor to ground.
I'm currently building my first servo project using Gecko's and have read nearly all there is on the forum to gain knowledge and this was the only thing that stumped me. My voltage will be 74V which is near the limit of the Gecko drive and am quite concerned.
I'm assuming that I could probably get away without problems because my servo driving the largest load is under 500W so not that powerful and it's only moving a 800mm mill table and if I keep the accel/decel times in Mach3 longer it wont raise the power supply voltage.
The other thing you need to watch out for is using a motor whose voltage rating is larger than the drives rating. Looking on Ebay for motors as I have done, most are rated at about 90-110v once you go above the 24v mark which is a bit above the Gecko drive's rating of 80v.
The thing most people don't realise is that the motor once it's driven by a mechanical load and not the drive ie: during deceleration, becomes a very good generator and if the motor's rated voltage is larger than the drives then you'll end up with a black crispy thing where the drive used to be.
There are several things that can be done with using a drive without a dump resistor built in which is,
Longer accel/decel times fixed in the software ie:Mach3
Connecting a voltage clamp across the power supply or for the electronically minded what about a voltage sensing circuit that either switches in a resistor placed across the power supply or that disables or faults the drive if the voltage gets too high.
Personally I'm going for the 'adjust the software approach' and see what happens.
If I end up with a burned crispy thing where the drive was I'll certainly be posting my findings on the forum to let you guy's know.