Revit Electrical Feature - Load Sub-Classification Motor

Revit has an electrical feature that is pretty much undocumented. And I do not claim to be an expert on this topic, but wanted to share what I do know and hear how/if others use this feature. I am talking about an electrical connector's ability to have a Load Sub-Classification Motor enabled as shown in this first image.

Before talking about how this appears to work, I will mention that the biggest problem we have is...

Revit Lighting Fixtures; Switching

Following up on my previous post, Revit Lighting Fixtures; Control Options, I want to cover Revit's ability - and limitations- related to switching.

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...

SKM Power Tools to Revit

As I mentioned in yesterday's post, there are no tools to connect SKM Power Tools to Revit that I am aware of. Thus, we have to do things, what little can be done, manually.

Minimize Overlap Between SKM Power Tools and Revit

At LHB, we also use SKM for the single line diagram, arc flash evaluation, and short circuit calculations.  There is no possible way that Revit can accomplish what SKM does for these functions.  We import/link the SKM DXF file of the single line diagram into Revit.

There is duplication of OCP devices that are indicated in (Revit)...

Revit to SKM Power Tools

Revit cannot do Short Circuit Calculations accurately in all cases. Thus, many firms use SKM Power Tools for this. There are currently no publicly available tools (that I know of) to link Revit to PTW in any way (PTW said they are unaware of any either last time I asked).

You can use Revit to create some of the “components” in PTW. In Revit you need to create...

ElumTools Blog Post: Luminaire Family Validation Made Easy

Matt Kincaid, software developer at Lighting Analysts, Inc., makers of AGI32 and ElumTools, posted on their blog about a new luminaire validation feature in ElumTools.

In case you don't know, ElumTools (ET) is an add-in for Revit which facilitates professional lighting analysis. One of the dialog boxes available within ET is the Luminaire Manager. Here we see a listing of all the light fixture families in the current Revit project and their settings. By default, all the settings come from the Revit family. Most changes made here, such as picking a different IES file or adjusting the Light Loss values, automatically get pushed back into the family in the current project.

Calculated point-by-point illuminance results in foot candles (FC)

Additionally...

Revit System Browser - Electrical Example

Autodesk Revit has a feature that many outside of the MEP discipline are aware of, called the System Browser. It can be turned on from the View tab, via the User Interface drop-down as shown below.

From this palette-type interface we can see what is connected, what is not, plus various loads and totals. Thus, it is an important place to review often to make sure you have a properly developed system - whether that be mechanical, electrical or piping (MEP).

As I mentioned in yesterday's post,

Total Facility Electrical Load Estimate in Revit

Overall Building Load:

In Autodesk Revit, if everything is setup and connected correctly - electrically, the utility transformer will list the entire electrical load for a building (or project). However, presenting this information in a proper tabular (i.e. schedule) view is not straightforward.

Challenge: Transformer’s cannot generate a panel schedule… which is a limitation of the family’s sub classification “Part Type”.

Is there a way to have only the larger of the AC or HEAT loads to show up on the load estimate schedule?

Revit 2018 Circuit Path Bug

Revit 2018 has a new feature for the electrical discipline, which allows the designer to develop a custom circuit path. This is done between the Panel and the Farthest Device. Previously, Revit would would only use the X,Y,Z of the connector at each end and a fixed offset from the level (this is still the default).

The circuit length is used to calculate voltage drop. Calculating voltage drop in Revit is still not always possible due to the way it automatically assigns wire size. I wrote about that here: Revit Idea: Change how wire is auto-sized or allow override for engineering judgement.

Turns out there is a bug in how Revit calculates circuit length...

Project Phases Disappear in Revit 2017

If you do electrical work in Revit 2017 there is a bug you should be aware of. The result of this bug is that all project Phases (i.e. Existing, New Construction) disappear as seen in the image below.

All phases missing from Revit project

Normally, phases cannot be deleted - just combined with an adjacent phase. But, in any case, the last phase cannot be eliminated from a project.

This is really bad and difficult to fix. Just creating new phases is not the answer as the Room/Space elements are technically still in the model but not accessible - remember, those elements are hardwired to the phase they were created in. Even if you create a new phase with the same name, that does not resurrect the Room/Space elements.

Only Autodesk Support can fix this issue. However, on most projects, in the midst of production, the time it would take to send the model and get it back from Autodesk would result in too much downtime for the project and staff. Thus, going back to the last backup, good local file or Windows previous version is the best option.

But you are asking, why or how might this happen? Good question. It appears to be narrowed down to using the Spline Wire command; starting the command, selecting one electrical connector in a family and then canceling the command (Esc key). However, this is not easily reproducible.

Here is what Autodesk currently has to say about this: https://knowledge.autodesk.com/support/revit-products/troubleshooting/caas/sfdcarticles/sfdcarticles/Phases-disappear-from-project.html

Here is a forum post about this same topic: https://forums.autodesk.com/t5/revit-mep-forum/project-phases-disappeared/td-p/6400515

So, if you are using the Wire command in Revit 2017, you should consider checking the Phases dialog before each Sync w/ Central.

Fun stuff.