Okay, let's break down this situation and clarify the grounding and bonding requirements. This can get confusing, so I'll try to be as clear as possible.

Understanding the Terminology Service

The conductors and equipment that deliver electric power from the utility to the wiring system of the premises served. It includes the service drop or service lateral, service entrance conductors, metering equipment, and overcurrent protection.

Service Entrance Conductors

The conductors from the service point (usually the connection point at the utility's supply) to the service disconnecting means.

Service Disconnecting Means (Service Disconnect)

The main switch or breaker that disconnects the entire building's electrical system from the utility. This is usually located inside the building.

Main Bonding Jumper (MBJ)

The connection between the grounded (neutral) conductor and the equipment grounding conductors at the service. This is crucial for creating a low-impedance path for fault current to return to the source (the transformer) and trip the overcurrent device (breaker or fuse).

Grounding Electrode Conductor (GEC)

The conductor that connects the grounding electrode (ground rod, water pipe, etc.) to the electrical system, usually at the service.

Equipment Grounding Conductor (EGC)

The conductor that provides a path for fault current from equipment back to the source. EGCs are typically wires or metallic raceways.

Grounded Conductor (Neutral)

The conductor that is intentionally grounded, typically at the service.

Analyzing Your Situation

You have a 225-amp service being installed, fed from an existing pass-through meter. You've described a small braided wire running into the ground from the meter, with a #6 conductor connecting it to the neutral lug.Here's the likely scenario and what the code requires:1. The Braided Wire and #6 to Neutral

The braided wire running to ground from the meter is likely the utility's grounding electrode conductor (GEC). The #6 wire connecting this to the neutral lug at the meter is likely part of the utility's grounding setup. It's there to ground the meter enclosure and provide a path to ground for the neutral at the meter.2.

Is that the MBJ? Most likely, NO. The utility's grounding and bonding at the meter is separate from your responsibility for grounding and bonding at your service disconnect. The NEC (National Electrical Code) requires that the MBJ be located at the first service disconnecting means (the first breaker or switch that can disconnect the entire building).3. Why You Still Need an MBJ at Your Service Disconnect



Fault Current Path

The purpose of the MBJ is to ensure that fault current has a low-impedance path back to the source from the equipment grounding system within your building. If a fault occurs on a metal appliance chassis, the EGC connected to that appliance needs a direct, low-resistance path back to the neutral at the service disconnect so that the breaker will trip quickly. Relying solely on the utility's grounding at the meter would likely result in a higher impedance path, slowing down the breaker tripping time and increasing the risk of shock or fire.

NEC Mandate

The NEC (specifically, Article 250) is very clear that the MBJ must be at the first service disconnecting means. This is a fundamental safety requirement.

Separation of Responsibilities

The utility is responsible for grounding their equipment and the neutral at the service point. You are responsible for grounding and bonding your electrical system downstream of the service point, starting at the service disconnect.4.

What You Need to Do



Install a Proper MBJ

At your 225-amp service disconnect, you MUST install a main bonding jumper connecting the grounded (neutral) conductor to the equipment grounding bus (the bus bar where all the equipment grounding conductors connect). The size of this MBJ must be based on the size of your service entrance conductors, according to NEC Table 250.102(C)(1).

Install a Grounding Electrode System

You need to have a grounding electrode system (ground rod, water pipe electrode, etc.) connected to your service disconnect via a grounding electrode conductor (GEC). The size of the GEC is determined by NEC Table 250.66, based on the size of your service entrance conductors.

Bonding

Ensure that all metallic enclosures, raceways, and other non-current-carrying metal parts are properly bonded to the equipment grounding system.

Important Considerations and Code References NEC Article 250

This is the primary article in the NEC that covers grounding and bonding. Read it carefully.

NEC 250.24(C)

Grounding at Buildings or Structures Supplied by a Feeder or Branch Circuit. Even though you're not technically being supplied by a "feeder or branch circuit", there can still be some applicability if your building is separate from the structure with the meter. In this instance, you'll want to consider this article.

Local Amendments

Your local jurisdiction may have amendments to the NEC. Be sure to check with your local electrical inspector.*

Inspectors Authority

Ultimately the local electrical inspector has the final say. They can interpert the code based on local conditions.

In summary: Do not rely on the utility's grounding at the meter as your main bonding jumper. You MUST install a proper MBJ and grounding electrode system at your 225-amp service disconnect to meet NEC requirements and ensure safety. Consult with a qualified electrician and your local electrical inspector to ensure compliance. Flag for review