Resource with elapsed days

Filipe,
Please, allow me to quell you uneasiness.

Create a resource calendar that does not have the 20 minute break for the equipment resource(s). To do that go to the Resource Sheet, select the equipment resource and then select Project > Change Working Time. Eliminate the 20 break period for each day. That will create a custom calendar for that resource but you will not see it listed in the Calendars tab of the Organizer or as a change to the resource Base Calendar. However, when you assign that resource to a task, that resource's daily work content will be the full 4 hours, assuming you did NOT select the option, "Scheduling ignores resource calendars".

Again, if you have separate tasks that use only the equipment resource, do NOT enter duration in days because remember, you day is 3.66666 hours. Enter duration as 4*60 = 240 minutes.

If your equipment also runs even when no labor resources are present (e.g. overnight or on weekends) a different approach is needed.

John