Why Do You Need a Tracer Wire?
A tracer wire is a wire with only one conductor laid along the path of municipal pipes that carry water, gas, or oil under the ground. Other names for the wire are locating wire and locator wire because it is used to trace the pipes underground in case the repair is needed. Most of the time, it is used for the single purpose of locating a pipe; however, it can also carry a radio signal. Other uses include drilling and irrigation systems
Unlike other cables, tracer wire is often not designed to carry an electrical signal. Instead, the wire is located with the help of a special device, a wire tracer.
What Types Of Wire Are Allowed As Tracer Wire?
Wire marketed directly as tracer wire is the one recommended for locating. This wire has HMWPE insulation made from high molecular weight polyethylene. The insulation is for direct burial.
Insulation has excellent resistance to abrasion, mechanical impact, oils, chemicals, and water. The thing that differentiates this insulation from other common types of polyethylene is its excellent abrasion resistance.
At Nassau National Cable, you may purchase HMWPE tracer wire with different sizes of insulation, PE-30 or PE-45. The former is thinner insulation, and the latter is the thicker one for more demanding environments.
Other types of wire that are used as tracers are simple bare copper wire and stranded wire. Excellent options are copper-clad steel, stainless steel, and coated copper wire. While bare copper is acceptable, the best options are insulated because they are protected by insulation, safer, and easily traceable. If you think the conditions where you lay the pipes allow for bare copper wire, you can buy one from here. Choosing bare copper wire is a cheaper route, but risks should be assessed nevertheless.
What Color and Size of Tracer Wire Should I Use?
Depending on the type of pipes that the tracer wire follows, various color codes are recommended in the United States. These recommendations are based on either the APWA uniform color code or general practices in the industry.
Blue wires follow water pipes, green follow sewer lines, and yellow follow natural gas pipelines. For communications, the preferred color is orange, while irrigation uses purple. For other unspecified uses, the preferred wire is black. You can use different colors depending on what the manufacturer offers, but the ones mentioned above are the most commonly used. Using them adds clarity to the routines.
The wire size depends on the instructions provided by local authorities. Usually, the wires are not too big, between 12 AWG and 18 AWG.
Tracer Wire vs. THHN: Can I Substitute?
There are instances when THHN is used as a tracer wire, but this is not a recommended practice. Nevertheless, the wire is still used as it is cheaper than standard tracer wire with HMWPE insulation.
THHN wire is not UF rated; therefore it is not suited for direct burial, and tracer wire is directly buried in the earth. Therefore, using THHN as a tracer wire might result in its fast damage, way faster than the cables suited to act as a tracer wire. THHN usually has nylon insulation that is susceptible to all kinds of damage underground.
Some may argue that tracer wire might not be subject to quick damage because it is not operational and rarely energized. THHN as tracer wire is generally not expected to last more than two to three years. Of course, pipelines are designed to last years, if not decades longer than that, so you will have to eventually replace THHN with a standard tracer wire. For this reason, using THHN or even bare copper wire instead of a standard tracer is not a great long-term investment.
However, the fact is that, in any case, it is best to use the wire suitable for direct burial. THHN wire will likely still be located if buried, but it depends. The best way to use THHN is as a building wire, just like it is intended. You can buy THHN aluminum and copper building wire from Nassau National Cable.
Tips On Installation
- Use high-quality waterproof copper connectors for the wire to work properly.
- Never twist tracer wires as this will disrupt the signal.
- The locating wire should face the direction of the pipe that it locates.
- Tracer wire should be grounded at a dead end.
- Upon installation, tracer wires are inspected by municipalities according to the local procedure.
