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20A B Curve 30mA A Type 6KA 1P+N RCBO (NB3LEG-B20)

CHINT NB3LEG-B20 is a 20A Type A RCBO with 30mA residual current protection, B Curve tripping and a 6kA breaking capacity. It provides combined overload, short-circuit and earth leakage protection in a compact 1P+N design.

All-in-One Protection: Guards against overloads, short circuits and earth leakage in one device. Type A Safety Performance: Detects AC and pulsating DC fault currents for use with modern electrical loads. 30mA Personal Protection: Helps reduce the risk of electric shock in everyday installations. Compact 1P+N Design: Saves space inside consumer units and fits standard DIN rails. 6kA Breaking Capacity: Provides reliable fault protection for domestic and light commercial use.
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SKU: NB3LEG-B20
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Product Details

The 20A B Curve 30mA A Type 6KA 1P+N RCBO (Model: NB3LEG-B20) from CHINT provides dependable protection for modern electrical installations. It combines over-current and residual current protection in a single compact unit, helping to keep people and property safe from electrical faults.

Rated at 20 amps, this RCBO is ideal for general lighting and socket circuits. The B Curve tripping characteristic ensures reliable performance on circuits with moderate inrush currents, while the 30mA residual current sensitivity offers essential personal protection against electric shock.

With a Type A residual current design, the NB3LEG-B20 can detect both AC and pulsating DC leakage currents. This makes it suitable for use with modern appliances and electronic equipment commonly found in homes and small commercial settings.

The unit features a 6kA short-circuit breaking capacity, delivering strong fault protection in demanding conditions. Its 1P+N configuration saves space inside consumer units, making it a practical choice where panel space is limited.

Manufactured to recognised safety standards, this RCBO is built for long-term reliability. It mounts easily onto a standard 35mm DIN rail, allowing for straightforward installation and maintenance.

Whether you are upgrading an existing consumer unit or fitting out a new installation, the CHINT NB3LEG-B20 RCBO offers a trusted, all-in-one solution for circuit protection.

Product Specifications

Electrical Specifications

  • Rated Current (In): 20A
  • Number of Poles: 1P+N
  • Tripping Curve: B Curve (3-5 In)
  • Residual Current Type: Type A
  • Rated Sensitivity (IΔn): 30mA (0.03A)
  • Rated Voltage (Ue): 240V AC
  • Rated Frequency: 50Hz
  • Rated Short-circuit Capacity (Icn): 6,000A (6kA)
  • Rated Residual Making and Breaking Capacity (IΔm): 3,000A
  • Insulation Voltage (Ui): 500V
  • Rated Impulse Withstand Voltage (Uimp): 4,000V
  • Break Time under IΔn: ≤ 0.1s
  • Energy Limiting Class: 3
  • Release Type: Thermo-magnetic

Mechanical & Installation Data

  • Mounting: 35mm DIN Rail (EN 60715) via fast clip device
  • Terminal Connection Type: Cable / U-type busbar / Pin-type busbar
  • Connection Direction: From top
  • Terminal Size (Cable): Up to 10mm² (18-8 AWG)
  • Terminal Size (Busbar): Up to 16mm² (18-5 AWG)
  • Tightening Torque: 2.0 N·m (18 In-lbs)
  • Electrical Life: 2,000 operations
  • Mechanical Life: 2,000 operations
  • Protection Degree: IP20
  • Contact Position Indicator: Yes (Visual status window)
  • Pollution Degree: 2

Environmental Specifications

  • Ambient Operating Temperature: -5°C to +40°C (Daily average ≤ 35°C)
  • Storage Temperature: -25°C to +70°C
  • Reference Temperature for Tripping: 30°C

Key Features

  • Space-Saving Design: Occupies only a single-module width (18mm) to maximize available space within consumer units and distribution boards.
  • Type A Safety: Engineered to handle the residual current profiles of modern electronic equipment, including computer power supplies and LED lighting drivers.
  • Complete Protection: Provides robust protection against overloads, short circuits, and earth leakage faults, significantly reducing fire and shock hazards.
  • B-Curve Optimized: Specifically suited for the protection of people and long cable lengths in systems where low inrush currents are expected.

Standards & Compliance

  • Primary Standard: BS EN 61009-1 / EN 61009-1
  • EMC Standard: EN 61543
  • Directives: Low Voltage Directive 2014/35/EU, EMC Directive 2014/30/EU
  • Certification: CE Marked, Intertek Verified

Shipping & Collection

Tracked Delivery (Currently 1-3 business days):

  • Free over £250.
  • £5.99 for orders under £250.
  • £5.99 for orders under £50.

Next Business Day Delivery:

  • £15 Flat Rate.

Collection:

  • Free to collect from our warehouse.

Pre-Order:

  • 5-10 Business Days delivery unless otherwise stated.

Shipping Policy

Datasheets
20A B Curve 30mA A Type 6KA 1P+N RCBO (NB3LEG-B20) - Data Sheet
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