Chapter Twelve -

Wire and Cable Management

Avid readers of this column will, by now, have quite a collection of wiring in their mobile house, what with battery cables, inverter wiring, lighting circuits, AC supply, DC branch cables, and all of this interconnecting spaghetti that makes the various pieces of the puzzle work together.

What is needed now (or perhaps much earlier) is a way to keep all of this wiring neat and orderly. Using the old trick of wrapping the cables in black electrician's tape is barely adequate, as the tape tends to get gummy after a time, and while the wires are protected in the tape, they are also impossible to follow, repair or replace without removing much or all of the black plastic covering.

The goal of bundling and routing wiring is made much easier by the use of several inexpensive and easily available commercial products. The first, and most useful is the common nylon wire tie. These self-cinching plastic straps come in a variety of widths and lengths, and can also be procured in various colors as well. Some wire ties have an eyelet in the end, which makes them perfect for creating wiring looms attached to wood or metal surfaces with screws. Placing a wire tie around bundled wiring every few inches can be a very effective way of preventing damage and keeping wiring neat and out of the way.

In places where screws can not be used to secure the ties, self-adhesive mounting blocks which have a slot for the wire tie to pass through are available. The double-sticky foam tape holds fast to nearly any clean surface. In many cases where wiring is routed across wood surfaces, the ties can be passed through the loop formed by common round-headed staples.

While installing cabling in radio stations, I sometimes go through a thousand or more cable ties, cutting apart bundled wiring under counters and inside racks to add additional wiring as the project progresses. They are a very effective way of creating custom wiring harnesses when a line of ties are installed and then used to route wires between locations.

In places where wiring will be subject to physical damage, or where wires pass through normally inaccessible areas, place your wiring inside flexible non-metallic conduits. Even suitably sized rubber or plastic garden hose will make the job of adding or replacing wiring running through a closed or inaccessible area much easier. If you plan on running wires through your floor, walls or ceiling, and you ever think you may need to access it for changes in the future, you'll be very glad to be able to 'fish' your wiring through a conduit, instead of tearing out the woodwork to get at the wiring inside.

Labeling wiring and cables is an extra-credit exercise, but a well thought out numbering system and indicating charts will save untold time when changes or repairs are attempted years in the future. All manner of labeling products exist, from numbered self-adhesive tape, to peel-off legends, all the way up to complete labeling systems which allow you to enter text on a keyboard and then print on an adhesive wire marker. Personally, I prefer writing a short description of the wire's purpose using a sharp-point permanent marker on a piece of white heat-shrink tubing, which is attached to each end of the wire.

Now I am going to give you a tip that is worth it's weight is gold (how much does a 'tip' weigh, anyhow?), and that is to always leave a little extra wire at each end of the wire's run. This is called 'service loop', and you will be pleased that you provided yourself an extra inch or two of wire when you need to move a terminal to a different connection, repair a damaged or corroded end, or move a piece of equipment a few inches in one direction or another to make room for something else. Basically, a service loop is when you by-pass the device you are connecting the wire to and then loop back to make the connection, leaving extra wire. For devices which are not accessible from the rear, leaving an extra half-foot of wire or more wouldn't be extreme. Imagine trying to connect or disconnect a lamp or switch which won't pull far enough from the wall to let you get your fingers behind it! Aaaarrgghhh! Wire is cheap, use enough of it to make working with it easy. You'll end up with a more reliable system, as the connections won't be strained, and you'll be able to make sure each connection is secure and solid.