The Niglon MCB6B1-40 40A Type B Miniature Circuit Breaker is a single-pole protective device designed to provide reliable overload and short-circuit protection for suitable domestic and light commercial electrical circuits.
Featuring a 40 Amp current rating, Type B tripping characteristic and 6kA breaking capacity, the MCB6B1-40 is suitable for appropriately designed electrical installations requiring 40A overcurrent protection, including certain dedicated appliance supplies and fixed electrical equipment circuits.
Manufactured in accordance with BS EN 60898-1, this compact circuit breaker features DIN rail mounting, bi-directional operation, a single-module width and screw terminals accepting suitable conductors up to 25mm².
40A Type B Circuit Protection
The Niglon MCB6B1-40 has a rated current of 40A and a Type B tripping characteristic, providing overcurrent protection for correctly designed electrical circuits.
Type B miniature circuit breakers are commonly used where connected equipment has relatively low starting currents and does not produce excessive inrush current during normal operation.
The breaker automatically disconnects the supply when an overload or short-circuit fault causes it to trip, helping protect electrical wiring against the effects of excessive current.
Type B Tripping Characteristic
The Type B tripping characteristic provides instantaneous magnetic operation at approximately 3 to 5 times the rated current.
For a 40A Type B MCB, this corresponds to an instantaneous magnetic tripping range of approximately 120A to 200A.
The correct circuit breaker rating and tripping characteristic must always be selected according to the connected load, cable size, fault conditions and installation requirements.
6kA Short-Circuit Breaking Capacity
The Niglon MCB6B1-40 has a 6kA (6000A) rated short-circuit breaking capacity in accordance with BS EN 60898-1.
This specifies the breaker's ability to safely interrupt short-circuit faults within its approved operating and test conditions.
The prospective fault current at the installation must be assessed to ensure that the selected protective device has an appropriate breaking capacity.
Suitable for 40A Electrical Circuits
The MCB6B1-40 can be used to provide overcurrent protection for a range of appropriately designed electrical circuits requiring a 40A protective device.
Potential applications may include:
- Appropriately designed 40A radial circuits
- Dedicated electric cooker circuits
- Suitable electric shower circuits
- Fixed electrical equipment supplies
- Domestic electrical distribution
- Light commercial electrical installations
- Compatible consumer units and distribution equipment
The suitability of a 40A Type B MCB depends on the connected load, conductor size, installation method, prospective fault current and disconnection requirements. Additional residual-current protection may also be required.
Single Pole DIN Rail Mounting
The Niglon MCB6B1-40 is a single-pole miniature circuit breaker designed for installation onto a compatible standard DIN rail.
Its compact single-module construction occupies approximately 18mm of DIN rail space, making it suitable for compatible consumer units and electrical distribution equipment.
The front-mounted operating lever allows the circuit to be manually switched on or off and reset following a trip, once the cause of the fault has been identified and corrected.
Bi-Directional Operation
Niglon specifies the MCB6B1-40 as bi-directional, allowing current to flow in either direction through the protective device within its approved operating conditions.
This provides additional flexibility for suitable electrical distribution arrangements, subject to the manufacturer's installation instructions and compatibility with the complete electrical system.
Bi-directional operation does not remove the need to verify consumer unit compatibility, busbar connections and any specific installation restrictions.
25mm² Maximum Cable Capacity
The Niglon MCB6B1-40 features screw terminal connections with a manufacturer-specified maximum cable capacity of 25mm².
The recommended terminal tightening torque is 2.5Nm, helping provide secure electrical connections when installed using suitable conductors and the correct termination method.
The selected conductor size must be appropriate for the circuit design and comply with the manufacturer's terminal requirements.
BS EN 60898-1 Compliant
The Niglon MCB6B1-40 is manufactured in accordance with BS EN 60898-1, the standard covering miniature circuit breakers used for overcurrent protection in household and similar electrical installations.
Niglon lists Semko certification, CE marking and UKCA marking for its Type B miniature circuit breaker range.
The device should be selected and installed by a suitably qualified person within compatible electrical distribution equipment.
Key Features
- Manufacturer: Niglon
- Part Number: MCB6B1-40
- 40 Amp rated current
- Type B tripping characteristic
- 6kA short-circuit breaking capacity
- Single-pole circuit protection
- 230V AC rated voltage
- Bi-directional operation
- Standard DIN rail mounting
- Compact single-module width
- Maximum cable capacity of 25mm²
- 2.5Nm terminal tightening torque
- Overload and short-circuit protection
- BS EN 60898-1 compliant
- Semko certification, CE and UKCA markings
- Suitable for appropriately designed domestic and light commercial circuits
Technical Specifications
| Manufacturer | Niglon |
| Manufacturer Part Number | MCB6B1-40 |
| HEM Model / SKU | NIG40MCB |
| Product Type | Miniature Circuit Breaker (MCB) |
| Rated Current | 40A |
| Tripping Characteristic | Type B |
| Breaking Capacity | 6kA (6000A) |
| Rated Voltage | 230V AC |
| Number of Poles | 1 Pole |
| Bi-Directional | Yes |
| Mounting Type | DIN Rail |
| Module Size | Single Module |
| Nominal Width | 17.8mm |
| Nominal Height | 82mm |
| Maximum Cable Capacity | 25mm² |
| Terminal Tightening Torque | 2.5Nm |
| Standard | BS EN 60898-1 |
| Certification / Marking | Semko, CE, UKCA |
Dimensions are based on Niglon's current range drawing. Installation must follow the manufacturer's instructions and applicable electrical regulations. Consumer unit compatibility should be checked before fitting. This MCB provides overcurrent protection and does not replace an RCD or RCBO where residual-current protection is required.
Why Choose the Niglon MCB6B1-40?
The Niglon MCB6B1-40 40A Type B Miniature Circuit Breaker combines dependable overload and short-circuit protection with compact DIN rail mounting and a straightforward single-pole design.
Its 40A rating and Type B tripping characteristic make it a practical option for correctly designed dedicated appliance supplies, fixed electrical equipment and other suitable electrical installations.
With a 6kA breaking capacity, bi-directional operation, 25mm² maximum terminal capacity and BS EN 60898-1 compliance, the MCB6B1-40 provides a professional circuit protection solution for suitable domestic and light commercial applications.
Any orders below £75 subject to £6.00 carriage
- Stock: 6
- Model: NIG40MCB
- SKU: NIG40MCB
- MPN: MCB6B1-40
