Today, locating is complex as telecommunications cables join utility lines in the underground environment. The underground cable wire locator relies on the basic technology--injecting an electrical signal onto the cable being located, to locating a specific circuit breaker, pinpointing wires before drilling and verifying dig sites underground. Underground wire finder is the rugged, economical solution for locating cable, wires and pipes that are underground no matter whether they are energized or de-energized.

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A cable locator has two basic components: a hand-held receiver and compact transformer(or transmitter). Both are battery-powered, relatively light and housed in weather-resistant cases. The receiver locates underground lines by detecting magnetic fields created by electrical current passing through cable or tracer wires. Information is displayed in a window at the top of the receiving unit.

Anatomy of underground cable locator

There are many types of underground wire finders, but they all functioned according to the same principles. The transmitter sends an electric signal which reaches the underground cables, which is then picked up again by the receiver. These devices can help you map an area before you start any actual work.

The transmitter puts an electrical signal onto the cable or pipe being traced, while the receiver picks up that signal, allowing the locator operator to trace the signal's path and follow the cable being located.

Usually receivers use different frequencies and modes to identify different types of utilities. Frequency choices can range from less than 1 kilohertz to about 480 kHz. With this range of frequencies, it is important to keep one thing in mind, if you want to start out at the lowest frequency and if that frequency works, don't change it, lower frequencies seem to bleed over less and stay on the conductor you are attached to better.

The three most common methods of sending signals onto the cable are direct connect, general induction, and inductive coupling. In the inductive coupling method, the cable must be grounded to form a complete circuit path. The direct-connect method allows you to physically attach your transmitter to the cable to be located. That may mean connecting to a cabinet or a pedestal and then gaining access to the shield that surrounds the cable, which is usually grounded at this point.

If directly attaching to the cable is impossible, then the induction method may be the logical choice. Here, you place the transmitter on the ground directly over the cable. Once the transmitter is turned on, it induces a signal into any nearby conductor within its range. This, of course, can lead to problems if there are multiple cables buried within close proximity because the signal could be picked up on a cable other than the one you are trying to trace.

Although inductive coupling doesn't let the user directly connect to the cable, underground wire finder provides a higher level of confidence than does general induction. It uses a donut-shaped coupling device that surrounds the cable and emits a signal onto the cable.

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