If you still need your resources to work on other tasks, then setting non-working time in the project calendar wouldn't work.

If you have created the "outage" calendar, you can assign that calendar to tasks which would normally require your acceptance and production availability. Double click on the task (or select all tasks you need modified and use the Multiple Task Information dialog box) and on the Advanced Tab, select the "outage" calendar. Check off "Scheduling ignores resource calendar" and any tasks assigned that task calendar will automatically move and not be scheduled for work during the outage.

I hope this helps.
Julie