Most underground pipe is plastic now. That's great for corrosion, but a locator can't find PVC or HDPE on its own. Tracer wire is what makes a buried line findable years from now, when the next crew digs nearby. Pick the wrong wire, or install it carelessly, and the line might as well be invisible.
Here's what I look at when helping a contractor choose tracer wire.
Start With the Job Spec
Before anything else, check what the utility, city or agency on your project requires. Many specify gauge, conductor type, jacket material and color. If the spec calls it out, follow it. Everything below is for when you have room to choose or need to understand why the spec says what it does.
Pick the Conductor for How It Goes in the Ground
Solid copper is the common choice for open trench work. It conducts well and is easy to strip, splice and terminate.
Copper-clad steel has a steel core with a copper outer layer. The steel adds tensile strength, which matters when the wire gets pulled with the pipe during horizontal directional drilling. Plain copper can stretch or snap on a long pull, and a broken tracer wire is a dead locate.
As a general rule, open trench work often uses 12 or 14 AWG, and directional drilling calls for heavier wire or a high-strength copper-clad product. Again, your spec has the final word.
Choose a Jacket Made for Burial
The insulation is what keeps the conductor from corroding through. Jackets made for direct burial, such as high-density polyethylene (HDPE), hold up to moisture and soil better than general building wire insulation. Don't grab leftover THHN from the electrical shop and call it tracer wire.
Match the Color to the Utility
Use the jacket color that matches the APWA uniform color code, so whoever digs later knows what's down there:
- Yellow: gas, oil, steam
- Blue: potable water
- Green: sewer and storm drain
- Purple: reclaimed water
- Orange: communications
- Red: electric power
Install It So It Keeps Working
Good wire is only half the job. A few habits make the difference:
- Keep it continuous. Run the wire along the pipe and keep it close to the line.
- Use direct-bury splice connectors. Plain wire nuts and electrical tape let water in, and corroded splices are among the most common reasons a tracer system stops working.
- Bring it up to access points. Terminate at test stations, valve boxes or access boxes so a locator can hook up without digging.
- Ground the ends where your spec calls for it, so the signal has a return path.
- Test continuity before backfill. It's a lot easier to fix a break while the trench is still open.
We're Here to Help
A-Best Industrial Inc. Fittings, Valves, and Tubing supplies tracer wire for contractors and utility crews across Southern California. See what we carry on our tracer wire page, and if your job also needs pipe, valves or fittings, we can help with that too through our industrial PVF line.
Not sure which wire fits your spec? Call us at 310-833-3353 or email sales@abesttube.com. We're open Monday–Friday, 8:00 AM–5:00 PM Pacific, with after-hours emergency service when you need it.