Okay, let's break down the situation and relevant code aspects for your apartment submetering installation with Grid Gear equipment.

Understanding the Concerns

Your company is concerned about tenants being able to disconnect power to the meters, so they want to tap the meters before any individual unit breakers. This raises definite safety and code compliance concerns. The core issue is the lack of overcurrent protection (OCPD) on the meter conductors where they tap directly into the main feeders.

Key NEC Sections and Considerations

Here are the relevant sections of the National Electrical Code (NEC), which is the most widely adopted electrical code in the US. Always consult the latest edition of the NEC and any applicable local amendments:1. NEC Article 240: Overcurrent Protection

This is a HUGE article. It's the heart of the issue.

240.1: Scope

Overcurrent protection is intended to protect conductors and equipment against overcurrent.

240.4: Protection of Conductors

Conductors must be protected against overcurrent in accordance with their ampacities as specified in Article 310. (Think of ampacity as the wire's safe current-carrying capacity.)

240.21: Location in Circuit

This is critical. It dictates where the OCPD must be located. In general, you need OCPD at the point where the conductor receives its supply. There are exceptions, but they are very specific and require careful consideration.

240.21(B) Feeder Taps

This is the section your company might be referencing, but it's often misinterpreted. It allows for "tapped conductors" under very strict conditions. Here's what makes it difficult to apply to your situation:

240.21(B)(1) 10-Foot Tap Rule

This allows a tap without OCPD at the tap point if: The tap conductor's ampacity is at least 1/10th the rating of the overcurrent device protecting the feeder. The tap conductor is enclosed in a raceway or otherwise protected from physical damage. The tap conductor does not exceed 10 feet in length. The tap conductor terminates in a single circuit breaker or fuse rated at or below the ampacity of the tap conductor.

240.21(B)(2) 25-Foot Tap Rule

This allows a longer tap (up to 25 feet) under even more restrictive conditions: The tap conductor's ampacity is at least 1/3rd the rating of the overcurrent device protecting the feeder. The tap conductor is protected from physical damage and terminates in a circuit breaker or fuse. The tap conductor's ampacity is not less than the rating of the device it supplies or the overcurrent protection at its termination. The tap conductors are installed in a raceway.

240.21(B)(5) Transformer Feeder Taps

This exception is specific to transformers, and unlikely to apply to your meter installation.2.

NEC Article 310: Conductors for General Wiring

This article defines the ampacity of conductors based on their size, insulation type, and installation conditions. You'll need to know the ampacity of the wires you're using for your CT connections and power feeds.3.

NEC Article 408: Switchboards, Switchgear, and Panelboards

This article covers the construction and installation of panelboards, including overcurrent protection.4.

NEC Article 90.4 Enforcement

The authority having jurisdiction (AHJ), usually a local electrical inspector, is the one that has the final say in interpreting and enforcing the NEC. You

must consult with the AHJ to get approval before beginning any work.

Why the Company's Approach is ProblematicThe company's idea of tapping directly off the main feeders without OCPD is likely a violation of the NEC unless you can strictly adhere to one of the very specific tap rules in 240.21(B). The potential consequences of not having OCPD are:

Fire Hazard

If a short circuit or overload occurs in the meter or the wiring to the meter, there's nothing to stop the current flow. This can cause the wires to overheat, melt insulation, and potentially start a fire.

Equipment Damage

Overcurrent can damage the metering equipment itself.

Code Violation

The installation will fail inspection, and you'll be required to correct it.

Possible Solutions and ConsiderationsHere's how to approach this safely and code-compliantly:1.

Overcurrent Protection at the Tap

The safest and most straightforward solution is to install overcurrent protection (fuses or circuit breakers) immediately at the point where you tap the main feeders to supply the meter box. This OCPD should be sized appropriately for the ampacity of the conductors feeding the meter. This is generally the best and most compliant solution.2.

Carefully Evaluate the Tap Rules

If you absolutely must tap without immediate OCPD, you must meticulously evaluate whether you can meet all the requirements of one of the tap rules in 240.21(B). Consider:

Wire Size and Ampacity

Can you use conductors with an ampacity that's at least 1/10th or 1/3rd (depending on the tap rule) of the main feeder's OCPD rating?

Distance

Can you keep the tap conductors within the 10-foot or 25-foot limit?

Termination

Do the conductors terminate in a single circuit breaker or fuse rated appropriately?

Raceway

Are the tap conductors installed in a raceway for physical protection?

Consult with an Electrical Engineer

Seriously consider consulting with a licensed electrical engineer. They can perform calculations, design the system to meet code, and provide documentation for the inspector.3.

Meter Enclosure

Ensure the meter enclosure is properly rated for the environment (indoor/outdoor, NEMA rating).4.

CT Connections

Make sure the CT (Current Transformer) connections are properly made and that the CTs are rated correctly for the expected current. Low voltage wiring can get damaged if left open circuited.5.

Design and Layout

Consider the physical layout and access to the meters. Make sure there's sufficient working space around the panel and meter enclosure for safe maintenance and troubleshooting.6.

Documentation

Keep meticulous records of all wiring, conductor sizes, OCPD ratings, and any calculations you performed to demonstrate code compliance.

Steps to Take1.

Review the NEC

Get a copy of the latest NEC (National Electrical Code).2.

Consult the AHJ

Talk to the local electrical inspector before you start any work. Explain your proposed installation and get their feedback. They may have specific requirements or interpretations of the code that you need to follow.3.

Consult with a Licensed Electrician or Engineer

If you are not a licensed electrician, it is highly recommended that you consult with one. They can help you design a code-compliant system and ensure the installation is safe.4.

Product Listing

Make sure the Grid Gear equipment you are using is listed and labeled by a recognized testing laboratory (e.g., UL, ETL).

In ConclusionYour company's desire to prevent tenants from disconnecting power to the meters is understandable, but safety and code compliance must be the top priorities. Tapping directly off main feeders without overcurrent protection is generally not* permitted by the NEC. You need to find a solution that meets code requirements and protects against overcurrent hazards. Start by consulting with the AHJ and a qualified electrical professional. Do not proceed without their approval. Flag for review