Imagine the internet to the President’s suite is down. You pull up the drawing on your iPad to find the broken equipment or cable and it’s not in the rack! Madly scrambling, you finally call the installation company who mentions they rehabbed that system 18 months ago. “Who did you give it to?” you ask. “We turned it in, but we can send you an archive copy…tomorrow.”
Another angry call from the President. Then you notice another drawing not in the index but referencing the rack in its file name. You open it and find a later Issue or revision number and date, but a different, non-standard, file name. So you make a mental note to talk to…someone tomorrow about file update procedures.
This is an example of how the National CAD Standard (NCS) V6 sections on file naming, issue noting and floor numbering are critical to creating, archiving and recalling the correct sheet from the sheet set. NCS V6 UDS Sections are also recommended for BIM implementation and can help reduce the expense of transferring building data from design applications to facility management applications. Let’s take a look at another example of how standardized symbols and CAD standards can simplify facility operations:
What the #$@% does “T” mean? You’re preparing for a company-wide teleconference and can’t identify the access port for the video feed on the wall. One port says “T” and the other “S”. So you quickly look up the room drawing and find 2 unfilled triangles. One is marked “T” with a DB9 connector, so “T” probably doesn’t stand for telephone. The other is marked “S” with an RCA connector, so it could be a speaker output. But there are no other annotations or legend references on what these mean. So you go to the drawing set abbreviations schedule and are still no better off.
This Never-Never Land is the result of poor, non-standard symbols and abbreviations. In NCS V6 UDS Module 5: Terms and Abbreviations, there are over 2600 terms used in buildings, including new communications terms. In it you find “T” means tread and “S” means south—so you still don’t know anything. If the NCS abbreviations had been used, you would know that the “T” should be “TPAN” for touch panel—a touch screen remote control used with the teleconference system and that the TPAN is mounted on a nearby desk. You would also know that “S” should have been “SRC” for source of the teleconference signal and you would need an adapter to hook up the video camera.
What do those triangles mean? Since you are still stymied about the triangles, which you know are used for telephone and data ports, you search for the symbols list and find it has 2 unfilled triangles, one marked data and the other phone. You also find 2 filled triangles marked data and phone. How can the same symbols represent different objects? Now you need to search for the diagrams sheets to find the answer. NCS V6 says: “Symbols are graphic representations of objects, line types or materials.” Symbols, in other words, should be simple representations of complex technology, and can be standard shapes or may resemble the equipment or materials. In earlier NCS versions, there was some confusion about port symbology. In NCS V6, 48 new AV and communications symbols were added that follow the ANSI J-STD710 standard, which agrees with the BICSI and TIA symbols for ports. See the sample classroom floor plan (Figure 1), which shows:
- Data port triangles are filled, open triangles are phone, a split triangle with one side filled is a data and phone port, whereas a split unfilled triangle is a miscellaneous port. See Figure 1 for examples of different NCS V6 ports and Figure 2 for a possible solution for this scenario.
- Many of the symbols look like what they represent (e.g., screens, projectors, speakers).
- Each symbol has attributes defining mounting, technology and a legend reference number.
- There is a clear side legend which follows NCS UDS guidelines which shows the legend number, the symbol and a short description of each.
In the above example, the Figure 2 floor plan drawing shows the two wall ports with three connections and how other devices are connected to wall ports—even down to the desk number upon which the control panel is mounted. If it had a good legend, as shown in Figure 1, you’d have a clear understanding of how the teleconference needs to be set up—because the drawings and the abbreviations would all follow NCS V6.
In earlier NCS versions, there was some confusion about port symbolism. In NCS V6, 48 new AV and communications symbols were added that follow the ANSI J-STD710 standard, which agrees with the BICSI Data that port triangles are filled, open triangles are phone, a split triangle with one side filled is a data and phone port, whereas a split unfilled triangle is a miscellaneous port. See Figure 1 for examples of different NCS V6 ports and Figure 2 for a possible solution for this scenario
In all of these scenarios, operations and maintenance personnel needed to rely on the paper or PDF documents derived from CAD or BIM, but these efforts were hampered by a lack of adequate Sheet consistency. Clearly, the U.S. National CAD Standard was not followed, as it provides uniformity in sheet organizing and naming, sheet legend notes, correct symbols, and symbol attributes, as well as using recognized standard abbreviations. In addition to redrawing 1300 symbols to ANSI dimensions and adding 110 new and revised symbols, the newly released U.S. NCS V6 also includes BIM implementation guidelines, new and revised “Communications Terms and Abbreviations”, and updated Uniform Drawing System (UDS) sections on file naming, scaling, floor numbering, and text notes.
Don’t buy into the idea that just because paperless design and 3D BIM are hot new items that CAD standards should be left to geeks using drafting desks – ensuring the most recent NCS version is always followed they can save you trouble and improve construction and maintenance documentation in your building operations.
Dr. Walter Black is the founder of AVSymbols.com.
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