When you have light fixtures and switches (devices) placed, you can specify which switch controls which lights. It was originally only part of Revit MEP, and does not tie into the Lighting Groups covered in the previous post.
This feature is mainly used in documentation. Tags are added to indicate which switch controls which lights. This is typically only done when there are multiple switches in an area.. otherwise it is obvious and tagging is just unnecessary clutter on the drawings.
When you select a light fixture in Revit, the Switch option is presented on the Ribbon.
Once a Switch system is created for a light fixture...
the Switch option goes away and is replaced by a new Switch System tab on the Ribbon. Here you can Edit Switch System and also Select Switch.
Clicking Edit Switch System enters an edit mode where you can select all the lights controlled by a single switch. You can also remove lights.
Switches are placed using the Device\Switches command on the Systems tab. These are wall switches (like the ones in the photo above) or ceiling sensors.
To assign a switch, click the Select Switch option... in this example I selected a ceiling mounted occupancy sensor. Once the switch is assigned, and while in edit mode, we see dashed lines connecting the switch and lights.
A tag can be placed, using the SwitchID parameter to document which switch controls which lights. The big limitation here is we can only assign one switch to a group of lights. This does not allow for proper documentation for 3-way and 4-way switch systems. When the switches are on the same floor, we can tag the first switch twice and just move the tag over near the other switch. But, when the switch is on another floor, like in a stair shaft, that trick does not work.
I am sure I posted a Revit Idea about this, but cannot find it... and from a quick search I found two you should go and vote for. Hopefully someone at Autodesk can combine there so they get more visibility:)
Revit Ideas:
- https://forums.autodesk.com/t5/revit-ideas/light-switch-systems/idi-p/6494064
- https://forums.autodesk.com/t5/revit-ideas/3-way-switch-circuits/idi-p/6557877
Here is a good related idea by Jason Boehning (from CAD Learning):
https://forums.autodesk.com/t5/revit-ideas/system-browser-show-switch-systems/idi-p/6828168
The next image is from our MEP Productivity Pack, and shows another variation on switching; we have a double-gang box and each switch controls half the bulbs in each fixture.
