The electrical system should be connected by a grounding electrode conductor (GEC)—using a clamp listed for that purpose—to a grounding electrode installed near in the soil near the service.
Grounding Electrode Conductor Minimum Sizes
- 6AWG copper or 4AWG aluminum or larger if the only electrode is a driven metal rod/buried pipe
- 4AWG or larger if the only grounding electrode is rebar in the footing.
- The grounding electrode conductor (GEC) should be connected to the grounded (neutral) service conductor at an accessible point between the load end of the service drop or service lateral and the neutral bus bar in the service panel or at the neutral bus bar
- The electrical system should be connected to a grounding electrode or electrode system. Only three types will be visible:
Visible Grounding Electrodes:
- Driven rods are the most common. They are required to be driven to their full 8’ length, but you will not be able to confirm length visually, so you should disclaim it. Rods may be driven at an angle not to exceed 45°. When two 6’ rods are used they should be placed no closer together than 6’.
- Metal underground water pipes may serve as grounding electrodes. The GEC should be connected to the pipe within 5’ of the point at which it enters the ground. If an inline water meter is installed, it should have a jumper installed.
- Ufer grounds are acceptable as service grounding. A Ufer ground is steel rebar encased in a concrete footing. The rebar is bent to protrude from the footing, providing access for clamping the GEC.
Grounding Electrodes, not visible:
These types of grounding electrodes are acceptable, but not visible. Ask for documentation:
- Ground ring: a ground ring is a buried bare copper conductor that encircles the structure that it protects.
- Plate electrode
NOTE: In most jurisdictions, gas pipes should NOT be used as grounding electrodes.
- Grounding and grounded (neutral) conductors should terminate on separate bus bars.
- Unless designed to accommodate more than one conductor, each grounding and grounded (neutral) conductor should terminate in a service panel on an individual bus bar terminal that is not also used for another conductor. In other words, only one conductor per hole. HOWEVER, Instructions on the label may permit more than one grounding (EGC) conductor of the same size per terminal.