Okay, I understand your situation. You're essentially using a junction box as a transition point for your service entrance conductors because your new meter/panel combo doesn't have a suitable top entry. Here's a breakdown of how to properly bond the junction box, considering the National Electrical Code (NEC) and best practices

NEC Requirements and Considerations
Service Entrance Conductor Routing

The NEC doesn't explicitly prohibit using a junction box in the service entrance, but it significantly increases scrutiny and must be done carefully. The inspector will want to see that everything is compliant and that you're not introducing any undue risks.

Sizing the Junction Box

You must size the junction box according to NEC 314.28 (A)(2) and (A)(3) based on the size of the largest raceway entering or leaving the box. In essence, it ensures the box is large enough to allow for proper conductor bending radius and not overcrowd the box.

Enclosure Bonding

This is your primary concern. You must bond the metal junction box to the service grounding electrode system. This is absolutely critical for safety.

Equipment Grounding Conductor (EGC)

Because this is part of the service entrance, you do

not use the term EGC. You use a "Grounding Electrode Conductor (GEC)." Grounding Electrode Conductor (GEC) Connection

You'll connect the GEC to the junction box in a listed manner.

Service Raceways

Ensure all raceways (conduit nipples, mast conduit) are properly bonded to the junction box using listed connectors or bushings.

Conductor Insulation

Service entrance conductors must be properly insulated for their voltage rating. Using the correct type of conductor (e.g., THHN/THWN) within the junction box and raceways is crucial.

Weather Rating

If the junction box is outdoors, it must be rated for wet locations (NEMA 3R or better).

Shortest Practical Run

The NEC favors the shortest practical run for service entrance conductors. This is especially true now that you're adding an extra junction box.

Inspector's Approval

This installation requires a thorough inspection and approval. Be prepared to explain your design and demonstrate code compliance.

Steps for Properly Bonding the Junction Box

Here's a step-by-step guide:1. Choose the Right Junction Box



Metal

Use a metal (steel or aluminum) junction box that is properly sized for the number and size of conductors passing through it. Consider a NEMA 3R enclosure for outdoor locations.

Properly Rated

The junction box needs to be rated for the voltage and amperage of your service entrance.2.

Connect the Grounding Electrode Conductor (GEC)



GEC Size

The GEC size is determined by the size of your service entrance conductors (refer to NEC Table 250.66).

Approved Connection

Use a listed connector or lug to connect the GEC directly to the metal junction box. The connector must be suitable for the size and material of the GEC (copper or aluminum). Typically, this will be a lay-in lug or a compression connector.

Clean Metal

Make sure the area where you connect the GEC to the junction box is clean and free of paint or corrosion. You may need to scrape away paint to ensure a good electrical connection. Use an antioxidant paste specifically for electrical connections.3.

Bonding Jumpers (If Necessary)



Multiple Sections

If your junction box is made up of multiple sections bolted together, you may need to use bonding jumpers to ensure continuity between all sections. The inspector will determine if this is needed.

Concentric Knockouts

If you use concentric or eccentric knockouts, remove all rings of the knockout. Use listed reducing washers, and bonding type locknuts or grounding bushings on both sides of the enclosure to maintain electrical continuity.4.

Bonding Conduit Nipples and Raceways



Bonding Locknuts/Bushings

Use bonding locknuts or grounding bushings on both ends of the conduit nipples that connect the junction box to the meter/panel combo and to the service mast conduit. These create a solid electrical connection.

Grounding Jumpers (If Necessary)

If you're using non-metallic conduit at any point, you will need to run a properly sized grounding conductor inside the conduit and connect it to the junction box and the meter/panel.5.

Conductor Management



Neat and Organized

Keep the conductors within the junction box neat and organized. Avoid sharp bends that could damage the insulation. Use appropriate connectors for terminating the conductors.

Torque

Torque all connections to the manufacturer's specifications. Loose connections are a fire hazard.

Important Considerations and Warnings Consult a Qualified Electrician

This is not a DIY project for someone without extensive electrical experience. Service entrance work is dangerous and requires strict adherence to the NEC. Always hire a licensed and qualified electrician to perform this work.

Permits and Inspections

Obtain all necessary permits before starting the work and schedule an inspection by your local electrical inspector. They will verify that the installation meets all applicable codes.

Power Company Coordination

Coordinate with your power company to disconnect and reconnect the service. Never attempt to work on live service entrance conductors.

Safety First

Wear appropriate personal protective equipment (PPE), including safety glasses and insulated gloves, when working with electrical equipment.

Local Amendments

Be aware that your local jurisdiction may have amendments to the NEC that apply. Check with your local building department.

Don't Cut Corners

This is the service entrance to your home. It's the most critical part of your electrical system. Don't try to save money by using substandard materials or cutting corners on workmanship.

In summary, your approach with the junction box can work, but it requires meticulous attention to detail, strict adherence to the NEC, and the approval of a qualified electrical inspector. Prioritize safety and code compliance above all else. It is highly recommended to get a few quotes from licensed electricians. A site visit is usually required to provide an accurate estimate. Consider having them look at all available options including relocating the service to a more favorable location to make a cleaner and potentially more cost effective installation.Disclaimer: This information is for general guidance only and does not constitute professional electrical advice. Always consult with a qualified electrician for any electrical work.* Flag for review