People - even professionals make a mistake by thinking that the most is the best. Or, that the most stringent codes should always apply. Imagine an office security system that is built using military standards that were designed for rough weather and harsh environments. Where the thinnest wire that can be used is over rated by a factor of ten for current and voltage.

This is an every day occurrence in many industrial systems. It is due to the "designer" having limited knowledge of the application of codes and the proper enforcement of each one for its own particular use. A military or government contractor will overbuild a system because he is used to the most stringent codes available. To me, this is a waste of money as well as a difficult system to modify and service. Imagine what happens to those fine connections with heavy wire, when some are removed and moved around a bit. Aside from the lack of room, they will rarely be put back correctly. When sacrifices are made as far as twisted wires and shields because this heavy wire isn't available in that type, we now have a system that is actually degraded. True the manufacturer of the system has good transient protection, but we are that much closer to a false alarm and much lower signal to noise ratios.

This is what happens when a government contractor tries to design a system for the commercial market. Way over priced on the backs of taxpayers, and a lesser or less stable system than otherwise.

In a harsh environment and outdoors, heavier wire is called for as is a better method of termination. But within a controlled environment and in a stable area, it is more important to filter out rfi and electrical noise.

At about 30 percent of the cost, to gain a more stable system, I don't see any justification not to abide by UL standards rather than military or equivalent codes.

The interesting thing about this entire subject is that it has nothing to do with the resistance of the system to being defeated or bypassed. It has nothing to do with the level of protection. What it does do is take the focus off the real design and place it on the size of the wire. A high security system would benefit from smaller wires, as they are more difficult to bridge or strip without breaking the conductor. A properly twisted pair of conductors fed into a balanced circuit can actually identify attempts to defeat or tamper with the circuit by the slight change in capacitance or resistance to ground with a cable being manipulated.

The same person will argue to install a motion detector at an exit door to unlock the door. Even though it can be defeated by sliding a piece of paper under the door from the outside. I have seen world class security consulting firms make this mistake time and again.

The answer is to find the right standard or code and follow it. The answer also lies in the "expert" taking off the blinders and looking at the true purpose of his or her work.