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40A 1 Pole B Curve 6KA MCB (NB1‑63B1P40)

The CHINT 40A 1 Pole B Curve 6kA MCB (NB1‑63B1P40) is a compact, reliable circuit breaker providing effective overload and short-circuit protection with a B-curve trip for general circuits and easy DIN rail installation.

Reliable Protection – Safeguards circuits against overloads and short circuits with a 40A rating and 6kA breaking capacity. Optimised Trip Curve – B-curve characteristic suits lighting and everyday power circuits without frequent false trips. Space-Saving Design – Compact single-pole unit fitting standard 18mm DIN rail width keeps distribution boards tidy. Durable Build – Engineered with quality materials and long mechanical life for consistent performance. Versatile Use – Ideal for domestic and light commercial electrical installations.
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SKU: NB1-63B1P40
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Product Details

The 40A 1 Pole B Curve 6KA MCB (Model NB1‑63B1P40) from CHINT is a high-quality, compact miniature circuit breaker designed to protect electrical circuits from overload and short-circuit faults. Built to trusted industrial standards, this single-pole MCB delivers reliable interruption performance and long-lasting service in domestic and commercial distribution systems.

Constructed with robust, durable materials and engineered for consistent performance, this MCB features a 40 ampere rating and a B-curve tripping characteristic, which means it is sensitive enough to protect standard lighting and general power circuits without nuisance tripping. The 6 kiloampere breaking capacity ensures dependable protection even under high fault conditions, making it an excellent choice for both new installations and upgrades.

Thanks to its single pole design, this breaker occupies only 18mm of DIN rail space, making it ideal for neat, space-efficient consumer units and distribution boards. Installation is straightforward on standard TH35 DIN rails, and the breaker is suitable for use in environments with operating temperatures from -5 °C to +40 °C.

Whether you are protecting lighting circuits, power outlets, or control panels, the NB1‑63B1P40 provides simple yet robust circuit protection that meets everyday electrical safety needs throughout homes, offices, and light commercial spaces.

Product Specifications

Electrical Specifications

  • Model: NB1-63B1P40
  • Rated Current (In): 40A
  • Number of Poles: 1P
  • Tripping Curve: B Curve (3-5 In)
  • Rated Voltage (Ue): 230/400V AC
  • Rated Frequency: 50/60Hz
  • Rated Short-circuit Capacity (Icn): 6,000A (6kA)
  • Rated Insulation Voltage (Ui): 500V
  • Rated Impulse Withstand Voltage (Uimp): 4,000V (4kV)
  • Energy Limiting Class: 3
  • Power Loss per Pole: 5W
  • 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
  • Terminal Size (Cable): Up to 25mm² (18-4 AWG)
  • Terminal Size (Busbar): Up to 10mm² (18-8 AWG)
  • Tightening Torque: 2.5 N·m (22 In-lbs)
  • Connection Direction: From top and bottom
  • Electrical Life: 4,000 operations
  • Mechanical Life: 20,000 operations
  • Protection Degree: IP20
  • Contact Position Indicator: Yes (Color-coded visual indication)

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
  • Pollution Degree: 2

Dimensions

  • Width: 18mm (1 module)
  • Height: 86mm
  • Overall Depth: 78mm

Key Features

  • Reliable Protection: Engineered to protect circuits against short-circuit and overload currents, specifically for TN and IT earthing systems.
  • Integrated Safety: Features a trip-free mechanism, ensuring the circuit breaker operation cannot be defeated by holding the handle in the "ON" position.
  • Efficient Cooling: Includes a built-in heat dissipation gap to provide better cooling during sustained operation.
  • Visual Status Monitoring: Equipped with a color-coded contact position indicator that provides clear visual confirmation of the device status and insulation function.
  • Flexible Installation: Features an extendable DIN-rail holder for easy installation and terminals that accept both wire and various busbar types for reduced installation costs.

Standards & Compliance

  • Primary Standard: IEC/EN 60898-1
  • Certification: CE Marked, ASTA Licensed, VDE, KEMA, SEMKO, RCC, UL 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.

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