CHINT NB7 Miniature Circuit Breaker

Name: CHINT NB7 Miniature Circuit Breaker
Brand: CHINT
SKU: 60470149153

CHINT NB7 miniature circuit breaker is a compact product family for low-voltage distribution, DIN rail panel building, residential, commercial, and industrial electrical protection. It is suitable for distributors, installers, and buyers looking for practical standard MCB products.

Poles

Rated Current

Tripping Curve

Breaking Capacity

SKU: 60470149153 Category: Chint MCB

Description

CHINT NB7 miniature circuit breaker is designed for AC 50Hz/60Hz low-voltage distribution circuits and provides reliable overload and short-circuit protection for distribution boards, control panels, building electrical circuits, and export-oriented panel assembly applications. The NB7 series supports B / C / D tripping curves, 1P to 4P pole configurations, and DIN rail installation for residential, commercial, and industrial power distribution systems.

Technical Specifications

Parameter	Specification
Model Series	NB7
Type	Miniature Circuit Breaker (MCB)
Trip Curve	B / C / D
Rated Current	1A – 63A
Pole Number	1P / 2P / 3P / 4P
Rated Voltage	1P: 240/415V AC; 2P / 3P / 4P: 415V AC
Rated Frequency	50Hz / 60Hz
Breaking Capacity	6kA for B/C type 1–40A and D type 1–63A; 4.5kA for B/C type 50–63A
Electrical Life	≥ 4,000 operations
Mechanical Life	≥ 10,000 operations
Terminal Capacity	Copper conductor up to 25mm²
Tightening Torque	2 N·m
Standard	IEC 60898-1
Application	Low-voltage distribution / Residential and commercial panels / DIN rail mounting

Additional information

Weight	0.5 kg
Dimensions	22 × 22 × 22 cm
Rated Current	1A, 2A, 3A, 4A, 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, 63A
Poles	1P, 2P, 3P, 4P
Tripping Curve	B, C, D
Breaking Capacity	6kA

Technical Datasheet & Downloads

📄 Technical Documentation & Product Specifications

Download official engineering datasheets, certified test standards (IEC / UL / CE), wiring diagrams, and dimensional drawings for CHINT NB7 Miniature Circuit Breaker.

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Official Technical Datasheet (PDF) Complete electrical ratings, tripping characteristics, dimensions, and compliance specifications.

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2D/3D CAD & Dimensional Drawings STEP, DXF, and PDF CAD drawing files for panel builders and switchgear designers.

Technical FAQ & Selection Guide

💡 Frequently Asked Technical Questions & Selection Guide

Pure engineering specifications, tripping curve parameters, and electrical selection guidance for panel builders and system designers.

Curve Selection

How to choose between Tripping Curves B, C, and D for this miniature circuit breaker?

Curve B trips at 3–5 In (designed for resistive loads, electric heating, and domestic appliances with negligible inrush). Curve C trips at 5–10 In (the standard international choice for residential and commercial lighting, socket outlets, and small induction motors). Curve D trips at 10–14 In (specifically engineered for high-inrush inductive equipment such as industrial transformers, heavy motors, compressors, and welding circuits).

Breaking Capacity

How do I determine whether 6kA or 10kA breaking capacity is required for my installation?

Breaking capacity (Icn/Icu) must exceed the calculated prospective short-circuit fault current at the installation point. 6kA (IEC 60898-1) is standard for residential consumer units and sub-distribution branch circuits located downstream. 10kA (IEC 60947-2) is required for industrial facilities, main switchboards, commercial distribution panels, or circuits situated close to supply transformers where fault levels are high.

Poles & Neutral Isolation

How to choose the correct number of poles (1P, 1P+N, 2P, 3P, 3P+N, 4P) for single-phase and three-phase circuits?

For single-phase 230V circuits: 1P provides active phase protection; 1P+N or 2P isolates both live and neutral lines simultaneously (essential for TT earthing systems and sensitive sub-panels). For three-phase 400V systems: 3P protects balanced 3-wire motor loads; 3P+N or 4P is required for 4-wire mixed single-phase loads to ensure complete neutral disconnection during isolation.

DC vs AC Application

Can this circuit breaker be used in DC circuits (Solar PV, Battery Storage, Telecom)?

Standard AC breakers cannot safely extinguish DC arcs due to the absence of natural zero-crossing current. For DC circuits (60V to 1000V DC), select specialized DC breakers (such as DZ158-125 DC or NM8NDC series) equipped with permanent magnetic arc-blowout chutes and strictly observe polarity wiring to prevent arc re-ignition.

Modular Accessories & Interlocks

What modular accessories and mechanical interlocks can be fitted to this breaker?

Standard modular clip-on accessories can be mounted directly on the side without tools: OF (Auxiliary Contact for remote status indication), SD (Alarm Contact for trip fault signaling), MX (Shunt Trip for remote emergency tripping), MN (Under-voltage Release for voltage loss protection), and NXBZ mechanical interlock kits for manual generator/mains transfer switches.