You are correct. The inspector is incorrect.Here's why, based on the NEC (National Electrical Code): NEC 250.53(A)(3) Supplemental Electrode Required

If a single rod, pipe, or plate electrode doesn't achieve a resistance to ground of 25 ohms or less, a supplemental electrode is required.

NEC 250.64(A) Grounding Electrode Conductor Installation

This section dictates how the grounding electrode conductor (GEC) is installed. The GEC connects the service equipment (disconnect) to the grounding electrode. It sounds like you already have this in place with the #6 Cu conductor to the first rod.

NEC 250.64(F) Installation to Electrode(s)

This is where the critical distinction lies. If you have multiple electrodes (like your two ground rods), the connection to each electrode must comply with 250.64(A) (meaning, continuous to the service equipment), OR the electrodes can be bonded together with a bonding jumper.

NEC 250.53(C) Supplemental Electrode Bonding Jumper

This is the nail in the coffin for the inspector's requirement. This section specifically allows for the bonding jumper to be used to connect the supplemental electrode (your second ground rod) to the existing electrode. The bonding jumper must be sized according to 250.66, based on the size of the service entrance conductors. However, the bonding jumper never needs to be larger than #6 Cu.

In Summary

You have a #6 Cu conductor from your service disconnect to the first ground rod (which satisfies the GEC requirement for that electrode). The supplemental ground rod (the second one) can be connected back to the service equipment with a separate GEC (that complies with 250.64(A)), OR it can be bonded to the existing electrode with a bonding jumper sized per 250.66, but never required to be larger than a #6. An acorn clamp is an acceptable method of connection.

What to do


Respectfully point the inspector to NEC 250.53(C). Highlight the section that allows for the bonding jumper. Be polite but firm.2. Verify the Bonding Jumper Size

Ensure the bonding jumper you use is sized appropriately based on the service entrance conductor size, but again, keep in mind it never needs to be larger than a #6 Cu.3.

Proper Installation: Make sure the acorn clamp connection is clean, tight, and made for direct burial.You are correct in your understanding of the code. The inspector is imposing a requirement that the NEC does not mandate and, in fact, specifically allows an alternative to. Flag for review