5 Reasons You Can’t Locate Your Tracer Wire System
So you’ve installed a tracer wire system for underground utilities, but now you can’t locate it? Tracer wire systems are the most effective and accurate way to locate underground utilities, but unfortunately, too many are installed incorrectly, leaving utilities at risk for damage.
Before we talk about unlocatables, it is important to know what makes a system locatable in the first place. A locatable tracer wire system requires a complete electrical circuit. Just like the light switches in your home. If one section of the circuit is open, the electrical flow is stopped, and the lights go out. Similarly, if the current through a tracer wire system is interrupted, the detectable signal is lost, and you cannot locate it.
For a complete circuit to exist, a low voltage current is supplied from a transmitter attached to the tracer wire system. The tracer wire acts as a conductor and carries the electrical current to the strongest “ground”. Moist soil provides a natural return path from the grounding point back to the transmitter. The signal is attracted to the transmitter via a temporary ground stake positioned in the soil near the transmitter. A complete circuit has been created, and the tracer wire is now locatable. The goal is for the signal to be carried all the way along the tracer wire to the target before returning to the transmitter via the earth.
Now we’re ready to walk through the five most common reasons why your tracer wire system can’t be located:
- Dead Ends are not Grounded
First and foremost, make sure that all tracer wire dead ends are grounded. In order for a signal to reach its target (such as a hydrant, valve box, or manhole), the target must have a stronger “ground” than anywhere else along the line. That grounding point needs to be established with a 1.5-lb magnesium ground rod connected to the tracer wire at or near the target. The ground rod will pull the signal from the transmission point all the way down the tracer wire to the target. If your tracer wire system isn’t properly grounded, Mother Nature will carry that signal to ground before the signal has a chance to reach its target. Remember, electrical signals are pulled, not pushed, so it’s important to have ground rods installed at all tracer wire dead ends to pull the signal down the line. When a tracer wire system is properly grounded, it can be fully energized, and accurate detection is possible.
- Grounds are not Equal
Different potential “grounds” along an electrical path compete for the electrical signal, and we know that electricity always take the path of least resistance. So, the strongest ground wins. If the strongest ground isn’t at your target, you’ve lost your signal and won’t be able to locate the target line. If one dead end, for example, is grounded to a large steel pipe, and another dead end is grounded to a ground rod, the signal is going to travel to the steel pipe every time, since it provides a stronger pull. To prevent this from happening, be sure to install the same size ground rods at all dead ends.
- Bad Connections
A tracer wire system is only as good as its weakest connection. Waterproof, corrosion-proof connectors protect vulnerable wire splices and keep the locate signal flowing across connections. When other alternatives are used, like electrical tape, corrosion will result, causing your locate signal to stop at the connection point.
- Tracer Wire Insulation Not Designed for Direct Bury
Tracer wire insulation protects the conductor from moisture that can corrode the conductor. Make sure tracer wire is insulated with a material designed for direct bury. High density polyethylene (HDPE) is the most common for direct bury applications. In any case, DO NOT use THHN. THHN is a nylon coating and quickly deteriorates in the soil and sunlight. When the insulation deteriorates, it leaves the conductor exposed to the elements and corrosion. It puts your tracer wire and utilities at risk.
- Poorly Made Tracer Wire
Quality tracer wire is critical in carrying a detectable signal. The signal doesn’t stand a chance on a broken or corroded wire. There are several advantages of copper-clad steel (CCS) tracer wire over solid copper – the biggest being strength, not to mention more stable pricing. CCS tracer wire is also designed specifically for the installation application (open cut, directional drill, pipe burst) so that you have the right wire for the right job. And be sure to buy 100% made in the USA to ensure that both the conductor and the insulation are American-made. Some tracer wire claiming to be American-made is only partially made in the USA. Using inferior CCS can leave you with a low quality steel and gaps in the copper cladding leaving it susceptible to corrosion that can result in breaks, poor signal strength, and an unlocatable tracer wire system.
Tracer wire systems can be your best defense in protecting underground utilities if the right components are used and installed properly. Copperhead has made this part of your job easy! For an easy-to-follow tracer wire system installation guide, click on the link below.