Wiring system diagram for distribution box and electricity meter

A residential electric meter box connects the utility service to the main distribution panel via line, load, neutral, and grounding conductors, ensuring safe and code-compliant power distribution.

Core Components

Electric Meter: Measures electricity consumption; has incoming line terminals (Line) and outgoing load terminals (Load). Main Circuit Breaker: Protects the entire electrical system from overloads or short circuits. Neutral Bar: Connects all neutral wires (N) and links to the utility neutral.

Ground Bar: Connects the grounding wire (PE) to a grounding rod for safety. Branch Circuit Breakers: Distribute power to individual circuits like lighting, outlets, and appliances.

Wiring Steps for Single-

Phase (220V) SystemIncoming Line Connection (Utility Side): Live Wire (L1): Connect to the L1 terminal of the meter. Neutral Wire (N): Connect to the neutral terminal of the meter. Ground Wire (PE): Connect to the grounding terminal or ground bar.

Load Side Connection (To Distribution Box): Live Wires (L1/L2): Connect from the load terminals of the meter to the main breaker terminals in the distribution panel. Neutral Wire: Connect from the meter's neutral bar to the neutral bus bar in the panel. Ground Wire: Connect from the meter's ground bar to the panel ground bus and grounding electrode.

Branch Circuits: Connect individual circuit breakers to the respective loads (lighting, outlets, HVAC) following the panel layout.

Safety Considerations

Utility Disconnection: Always coordinate with the utility company to disconnect power before working on the meter box. Licensed Electrician: Installation or modification of service entrance equipment must be performed or supervised by a licensed electrician. Permits and Inspection: Obtain necessary permits from the local Authority Having Jurisdiction (AHJ) to ensure compliance with electrical codes.

Torque Specifications: Use a calibrated torque wrench to secure all lugs to manufacturer specifications to prevent loose connections.

Three-

Phase (380V) SystemsSimilar principles apply, but the meter box will have three line terminals (L1, L2, L3) and a neutral terminal. Each line connects to the corresponding main breaker in the distribution panel, with neutral and ground properly bonded.

Diagram Overview

The wiring flow is linear: utility power enters the top of the meter socket → passes through the meter → exits the load terminals → enters the main distribution panel → feeds branch circuits. The neutral bypasses the meter jaws and connects directly to the neutral bus, while the ground ensures safety and proper fault current path. Following this wiring sequence ensures safe, reliable, and code-compliant electrical service from the utility to the home circuits.