An isolated ground (IG) refers to a grounding practice used in electrical systems, particularly within sensitive electronic equipment environments, where the objective is to minimize electrical noise. This electrical noise or interference can be detrimental to the performance of electronic equipment.

The isolated ground system typically involves using a separate grounding conductor that is insulated and isolated from the building’s standard equipment grounding conductors and from metallic elements of the building structure. This separate grounding conductor is connected directly to the grounding electrode (like a ground rod) without any other connections, except to the electrical equipment that requires the isolated ground.

Here are some key points regarding isolated grounds:

  1. Purpose: The main purpose of an IG is to provide a direct path for electrical noise (from internal equipment or external sources) to go straight to the ground, thereby preventing this noise from affecting sensitive electronic equipment.
  2. Color Code: In the United States, per the National Electrical Code (NEC), an isolated ground conductor is often identifiable by an orange insulation cover, sometimes with a green stripe.
  3. Application: IG is commonly found in settings with sensitive electronic equipment, such as computer server rooms, data centers, laboratories, and recording studios.
  4. Consideration: When implementing an IG, it’s vital to ensure that the IG conductor is not mistakenly connected to other ground paths, which could defeat the purpose of the isolated ground.
  5. Installation: It’s critical to consult with electrical professionals when installing isolated ground systems. Proper design and installation ensure that the system operates as intended and doesn’t inadvertently introduce other problems.
  6. Safety: While an isolated ground can help reduce electrical noise, it does not eliminate the need for standard equipment grounding, which is essential for safety. Both grounding systems will coexist in locations where IG is used.

As with any specialized electrical system, the benefits and appropriateness of using an isolated ground depend on the specific needs of the application. Proper design, installation, and maintenance are crucial to ensuring its effectiveness and safety.