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Are there any safety concerns when working on telephones or wiring?

No special precautions need be taken when connecting or disconnecting phones from standard wall jacks. Once you move from consumer-level telephone technologies into the bowels of your home's telephone system, though, there are a few cautions.

  • Lightning is always a danger, so avoid doing any wiring during storms. Conventional wisdom has always been to not make phone calls during dangerous thunderstorms, anyway.
  • Never install a telephone in a wet location! You've all seen the movie where the bad guy throws the phone in the hot tub and electrocutes some poor character actor. Plan all installations so that the body of the phone cannot accidentally fall into a sink, tub, pool, or fish tank. As far as cordless phones go, you won't get electrocuted if the headset falls into the spa, but it will dampen your spirits.
  • Disable the line you are working on until you are ready to test the installation. It is true that the normal voltage in telephone wires, which provides the dial tone, is not dangerous. It is around 40 volts DC, with low amperage. Amperage provides the "push" to electricity. A good example of high voltage, low amperage is the static charge you get shuffling across a nylon carpet and then touching a doorknob or somebody's nose. The charge is on the surface of the skin, and doesn't have the "push" to penetrate into the body.

    However, when the phone rings, a series of high voltage AC surges come through the lines, up to 100 volts, and this can be dangerous, especially to people with health conditions, pacemakers, etc. And unless the phone company thinks your phone is busy, it will do its ringing thing, even if your phone is unplugged!!

    So disabling the line is simple- just take one phone of the hook, and wait for the phone company to finish its off-the-hook warning tirade. Then proceed with your work.


  • Always use new telephone cable when doing installations. Your installation is intended to last a long time, and it makes no sense reusing old cable that may have imperfections that will affect your telephone reception. A bad wire (or even a bad plug, outlet, or telephone, for that matter) anywhere in your home system can disable all your phones!
  • Use the right staples. Everyone can't afford or doesn't want a standard issue, 3/16" cable staple gun like the phone guys have. Use the generic, hammer-driven insulated staples, which will secure the cable without damaging it. Do not use flat staples, as from paper-type staplers or heavy-duty staple guns under any circumstance!
  • Do not hang anything on telephone cable. This is a real temptation if you do a run across an unfinished ceiling, such as a basement. Any weight will stretch and eventually break the fine wires inside. That's what plumbing pipes are for! Wink, wink!

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