2006 Code Changes Rule 10-806(4) Installation of System Grounding Conductors
Rule 10-806(4) Installation of System Grounding Conductors
This rule change will affect you if you’re in the habit of protecting system grounding conductors using iron or steel. Magnetic materials (iron or steel pipe or conduit) used for mechanical protection of grounding conductors must now be bonded to the conduit or pipe at both ends.
The reason, when fault current flows in the system grounding conductor, unless a portion of the ground fault current is permitted to pass through the conduit, the magnetic material will have a “choking” affect on the grounding conductor, increasing the impedance of the grounding conductor. This reduces the flow of ground fault current, causing a delay in the operation of fuses or circuit-breakers to remove the fault.
As with past articles, you should always check with the local electrical inspection authority for a more precise interpretation of any of the above.
This rule change will affect you if you’re in the habit of protecting system grounding conductors using iron or steel. Magnetic materials (iron or steel pipe or conduit) used for mechanical protection of grounding conductors must now be bonded to the conduit or pipe at both ends.
The reason, when fault current flows in the system grounding conductor, unless a portion of the ground fault current is permitted to pass through the conduit, the magnetic material will have a “choking” affect on the grounding conductor, increasing the impedance of the grounding conductor. This reduces the flow of ground fault current, causing a delay in the operation of fuses or circuit-breakers to remove the fault.
As with past articles, you should always check with the local electrical inspection authority for a more precise interpretation of any of the above.
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