If it's the Schwintek In-Wall slide that has the gear racks on the sidewalls, no.
To move it manually, you'll need to pull the set screw & lift the motors on each side to disengage them from the gears. As the gear racks on both sides are not tied together, you'll need two people to move the side in near unison. If you have a small slide, you might be able to do it with one person.
It would have been nice if they provided a manual method for this type... Consult your manuals or the Hitchhikers Guide (the interwebs) to determine the slide type and any possible manual options.
I have no experience with other slide mechanisms.
Let us know which type you have.
Formerly: 2000 Four Winds 26Q/Ford, '96 Kit Sportsmaster 22' 5th wheel, '91 Sunlite truck camper, Wildernest flip-top canopy