What to Do Before the Walls Go Up
With so much cable being installed in new and retrofit homes — i.e. infrastructure wiring, distributed audio, security, etc. — it's essential to have some form of installation documentation to keep the task efficient and manageable. In the commercial world, such documentation is covered in detail in ANSI/EIA/TIA-606. But in the residential world, it's not as standardized, which is why it's critical that you schedule and properly label your cables.
Why You Need a Cable Schedule
The cable schedule should be created prior to starting the installation. It is made from information on your plans or equipment list (all the equipment you will be installing in the home). It serves two purposes:
- It documents what needs to be installed and where, and it serves as an installation record to verify that everything was installed and tested, by whom, and when.
- It will also indicate any necessary deviations, such as a different type of cable or termination.
It will list each cable to be installed with from-to location and termination information. This schedule is used to perform the pre-wire and generate labels for each cable.
Making a Cable Schedule
While there are several software packages to help you generate job documentation, most everything you need can be done in a word processing or spreadsheet program. The illustration shown below is an example of a cable installation schedule created in Excel. The exact format and layout is not important, and you can make anything you want as long as the necessary information is covered. The fields used in this example were ones we like, and there is a reason for each one. CABLE SCHEDULEEach individual cable should be listed on a line, even if it is part of a bundled cable and should have a unique ID. The ID can be numbers, letters, or any combination, as long as you understand it and it works. A bundled cable (several cables — CAT5, RG6 — inside one jacket) has one ID number, but each cable in the bundle should have its own sub-ID. In the example, the first bundled cable has an ID of 4, but each cable in the bundle has its own sub-ID (4A, 4B, and so on). This is because each cable in the bundle must be labeled separately. The schedule should have a column to document (by a check-off or an installer's initials) that the cable has been pulled. Other columns will indicate that the cable has been tested at prewire, terminated and tested at trim-out. The next columns contain the source device or outlet designation, the termination (connector) used at the source, the destination device or outlet designation, and the destination termination. Note: This example assumes that the equipment schedule contains what type of hardware and rough-in are used at each end of the cable. In the example schedule, cable ID 1 is run from the IDP (Infrastructure Distribution Panel) to MBR-O9 (Master Bedroom, Outlet 9). It is terminated with a P8M (Plug, 8-pin, Modular) on one end and a J8M (Jack, 8-pin Modular) on the other. The code you use for the source and destination should be keyed to the outlet designation or the equipment that it connects and is derived from the equipment schedule. The next column indicates the type of cable (C5 = CAT5). The schedule can also contain an approximate length. This is a great time-saver since all the approximate cable lengths for each cable type can be added together to determine the length of each cable type needed on the job — easy to do if the schedule is made in a spreadsheet program. The length is used to make sure the required cable rolls are on the truck prior to heading for the job.
Labeling Your Cables
Besides testing, cable labeling is the most important step in prewire cable installation. Cable labeling must happen before the cable is pulled. A technique of rough-in/termination labeling works great when several cables are being pulled at once. When the cables to be pulled have been identified from the cable schedule, make two rough-in labels for each cable. Why a rough-in label? Labels always get damaged during prewire and are never in the right location when you trim-out. The rough-in label is temporary and will be replaced with the final label after the cable is cut to the trim-out length and terminated. The rough-in label may be a piece of white tape, a peel-and-stick write-on label, or a preprinted peel-and-stick label. Write the cable reference number (3,10, etc.) on each label and apply one of the labels to the end you are going to pull. Temporarily stick the other label on the corresponding cable reel or box. Pull the cables. Back at the end you pulled from, cut the cables to the necessary length. As you cut each cable, apply the other label (that you stuck on the reel or box) to the cable. When you are pulling multiple cables, this will prevent losing track of which cable is which. When the cables are trimmed to their final length and the insulation is stripped for termination, apply the trim label. This step should be a standard part of the cable termination process. This label is permanent and has the formal cable designation from the cable schedule from-to information (not just the ID).
What you print on the label is up to you, but it should include the ID and from-to designation from the cable schedule. For example, the label applied to the first two cables in the schedule would be in the format ID-FROM/TO, or 1-IDP/MBR-O9 and 2-IDP/MBR-O9, respectively. The coax in the bundled cable would be labeled 4C-IDP/MBR-O8. If you want to label it more descriptively, you can use the ID and a room/outlet name such as: "04 (MBR outlet 9)."
The rough-in label can be simple. Some installers just write the cable designation on the jacket with a felt-tip pen, but since this can smear easily, if you want to use a marker, you should first apply a length of white tape and write on the tape. Cut and label the tape for the other end of the cable at the same time (saving it on the reel or box). Blank peel-and-stick labels, clear and white, are available from electrical and cable distributors. These are large enough to wrap two to three times around the cable with a clear part to go over your writing to protect it. You could also use the preprinted number and letter labels available from the same sources, but you will likely run out of the numbers you need most. Trim-out final labeling can also use peel-and-stick labels that you write on, but a more professional installation will use a label from a portable label maker available at most office supply stores. TIP: You can use your PC and printer to preprint all the labels you need for the job in the shop. Use a sheet of clear or white label stock sheets. Small Avery peel-and-stick label sheets are available from any office supply store. You can even use the Cable Schedule spreadsheet directly to print the labels. Simply set up a page with a grid of cells that reference the to-from columns. By taking the time to follow these suggestions, you're likely to avoid all the major pitfalls encountered in most residential wiring projects. Grayson Evans has been actively involved in home automation and communication network development for more than 20 years. In 1992 he founded The Training Dept. to fill a void in industry education about home network technologies including CEBus and HomePnP. Since then the company has expanded into training materials including videos in all areas of residential technologies.
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