They may be intended to be used as
worklight circuits, but it really depends on how your facility is wired as to whether they can be controlled by the board or not. There is no quick yes or no answer as every facility is different.
Are these receptacles labeled in any way? Example: "WL-1".
Places to look for switches:
Stage Manager's
console
Stage Left/
Stage Right wings
Back of the
Proscenium arch
Near any door leading back
stage
If these are wired to the
dimmer racks, the receptacles really should be labeled. Are they mounted in the
raceway or are they in their own
junction box with dedicated
conduit? If the former, they are probably wired in with the dimmers. If the latter, look for a
switch somewhere. Now is also a good time to see if your rack(s) have any
relay modules. Just about any modern
console can control non-dims and
relay modules, so that won't give you much as to the intention of these mystery receptacles.
Have you tried plugging anything in to them? Try plugging a cliplight in to one and ghost your channels at about 15%. If the cliplight comes on, at least you know they are in with the dimmers.
If it doesn't, check your rack and make sure every module is receiving a signal. If any are not active, patch them in and try them.