redikillowatt
Member
- Location
- TX
On a remodeling addon job, the electrical contractor says the single grounding electrode needs replacing because it has rust at the top where a brass acorn clamp is attached (rod is exposed above grade). It is rusted, but clamp looks good. He also wants to replace the short GEC from panel to driven rod.
Is it necessary to replace a ground electrode because it has rust? For grins, I cleaned a spot on the rod below the brass grounding clamp & shined a spot on outside of brass clamp a bit & also a spot on GEC ( above the ground clamp). Resistivity between clamp & rod, and the GEC (from above clamp) to rod - below clamp - then were each < 1 ohm. Seems to indicate conductivity between both GEC, brass clamp & rod are still good, in spite of corrosion.
Can't say about resistance between such rusty ground rods & earth in a high rainfall area like this. He didn't check that.
The rod & clamp above ground were dry at the time of testing, but it has rained w/in last week.
I've worked on hundreds of older homes w/ similar looking rods & electricians never give them a 2nd look. I wonder if inspectors would require replacing rusty, but otherwise solid driven ground rods or what the actual requirements are for deciding if a driven ground rod needs replacing?
Is it necessary to replace a ground electrode because it has rust? For grins, I cleaned a spot on the rod below the brass grounding clamp & shined a spot on outside of brass clamp a bit & also a spot on GEC ( above the ground clamp). Resistivity between clamp & rod, and the GEC (from above clamp) to rod - below clamp - then were each < 1 ohm. Seems to indicate conductivity between both GEC, brass clamp & rod are still good, in spite of corrosion.
Can't say about resistance between such rusty ground rods & earth in a high rainfall area like this. He didn't check that.
The rod & clamp above ground were dry at the time of testing, but it has rained w/in last week.
I've worked on hundreds of older homes w/ similar looking rods & electricians never give them a 2nd look. I wonder if inspectors would require replacing rusty, but otherwise solid driven ground rods or what the actual requirements are for deciding if a driven ground rod needs replacing?