Product Overview

Our 400-frame 3x16mm² circuit breaker extension terminal is a high-performance accessory designed for three-phase 400A molded case circuit breakers (MCCBs), providing a standardized, reliable way to connect three circuits to a single MCCB. This terminal block is engineered to meet the standard wiring requirements of three-phase electrical systems, making it ideal for commercial and industrial distribution panels.

Standardized Three-Phase Wiring Configuration

This extension terminal is designed specifically for three-phase (3-Phase) electrical systems, with a standardized wiring configuration that aligns with industry best practices. The terminal block features three dedicated output circuits, one for each phase (L1, L2, L3), with a neutral connection point, providing a complete three-phase wiring solution. The optimized layout ensures balanced current distribution across all three phases, minimizing voltage drop and ensuring efficient operation of the electrical system.

The terminal block's design follows the standard three-phase wiring color-coding conventions (L1: brown, L2: black, L3: grey, neutral: blue), making it easy for installers to identify and connect the phases correctly, reducing the risk of miswiring.

Core Technical Specifications

Parameter	Specification
Rated Current	400A continuous duty, matching the MCCB's current rating
Number of Circuits	3 output circuits (L1, L2, L3) + neutral connection
Wire Compatibility	2.5mm² to 16mm² solid and stranded copper wires
Conductor Material	High-conductivity copper alloy with 5μm tin plating, providing excellent corrosion resistance and low contact resistance
Insulation Material	Flame-retardant, high-strength engineering plastic with UL94-V0 rating
Screw Torque	1.2N·m to 1.5N·m for secure wire connections
Dielectric Withstand Voltage	2.5kV AC for 1 minute
Insulation Resistance	> 100MΩ at 500V DC
Compatibility	Designed for all standard 400-frame three-phase MCCBs, including Schneider, Chint, ABB, Siemens, and Delixi models

product-1807-870

Material & Construction Quality

Conductive Components

The terminal block's conductors are made from high-purity electrolytic copper, which provides the highest possible conductivity and mechanical strength. The surface is plated with 5μm of tin, which provides excellent resistance to oxidation and corrosion, ensuring a low-resistance connection over the entire service life of the terminal block.

Insulation Housing

The housing is made from high-strength, flame-retardant engineering plastic with a UL94-V0 rating, which provides complete electrical isolation between the live parts and the mounting surface, as well as superior fire safety.

Mounting

The terminal block features a direct plug-in design that connects securely to the MCCB's main terminals, with pre-drilled mounting holes for additional stability in the panel.

Installation Guidelines

01/

Ensure the three-phase MCCB is in the OFF position and all power is disconnected before installation.

02/

Align the extension terminal with the MCCB's three-phase main terminals (L1, L2, L3), and push firmly to create a secure plug-in connection.

03/

Secure the terminal block to the panel with the provided mounting screws.

04/

Strip the three-phase wires to the specified length, insert them into the corresponding phase terminals (L1, L2, L3), and tighten the screws to the recommended torque.

05/

Connect the neutral wire to the neutral terminal, and tighten the screw.

06/

Verify all connections are secure and the phase wiring is correct before restoring power.

product-1807-870