The method David describes is a good that I've used too when I've had lots of animations to make and didn't want to muck up my model.
The idea is to treat the whole model as a component in a blank model. So save your main model and close it. Then open a blank model. File>Import and import your model file. Place it somewhere in the blank model. Now set up your animation scenes.
Now if you make changes to your original model file, they do not get updated automatically in the animation file. But you can reload the model manually. So in the animation file, right click on the model (which is still a single large component) and choose "reload" and then choose your model again. It will load in the newly modified version in the exact same spot.
Then repeat for all animations.
For me it depends what my other animations are though. If I have 4 animations that are identical camera locations but different styles (pure white and shadows with no lines, pure color no lines, pure white with lines and no shadows, inverted fog to act as a z-depth layer). I will set up all camera scenes to only store the camera location and not thet style or shadow info. Then I make 4 scenes that only store style and shadow info. These scenes do not get included in the animation. But it makes it easy to export my animation in a different style over and over until I get all the layers of animation I want.
So for me it always depends on what I am trying to export. Hope that helps,
Chris
