Why are Grounding Wires not Insulated?

Grounding wires are often not insulated since its purpose is to provide a low-resistance conduit for electrical faults (or) excess current to dissipate into the ground.

Insulation on these wires would contradict the objective by potentially trapping the electric charge within the wire, resulting in hazardous conditions such as electrical shocks, fires, (or) equipment damage.

By leaving grounding cables uninsulated, they can effectively route surplus power away from the equipment & into the ground, reducing electrical dangers and assuring the safety of people and property.

In some electrical applications, grounding wires are not insulated for two primary reasons:

Greater Conductivity

In grounding systems, especially for below-ground applications, a bare conductor provides superior conductivity. This is essential because the grounding system must efficiently transfer any fault current (or) leakage current back to the earth. Insulation would increase the resistance to this path, reducing its effectiveness.


For typical domestic wiring (such as NM cable), a bare copper grounding wire is just more cost-effective. The cost difference between insulated & bare wire for grounding is minor, and because grounding wires do not generally carry current, insulation is unnecessary.

However, it’s important to remember that not all grounding wires are bare. Here is an overview of some of the factors that affect insulation:

  • Underground, bare copper is recommended for increased conductivity. In above-ground installations, insulated grounding wires may be utilized for added protection or to meet special code requirements.
  • Armored cable (AC) utilizes the metal sheath as the ground, eliminating the requirement for a separate grounding wire completely.
  • Electrical rules may necessitate the utilization of insulated grounding wires in certain conditions.

Overall, whether to employ insulated or bare grounding wires is determined by the unique application, electrical code requirements, & cost factors.