WTB1-63 Mini Circuit Breaker (MCB) for 1P to 4P DIN-Rail Distribution
Pair the WTB1-63 with a matching pole count, current rating and trip curve for branch circuits from lighting to motor loads, high-inrush inductive equipment and general distribution. The 20,000-cycle mechanical lifespan and 6,000-cycle electrical lifespan keep replacement intervals long in circuits that switch frequently. Contact us with your required rating and configuration to confirm availability and lead time.
WTB1-63 is a modular miniature circuit breaker (MCB) for 230V/400V circuits that require overload protection, short circuit breaking and isolation from a single DIN-rail device. It complies with IEC 60898-1 and GB/T 10963.1, with CCC and CE certification across 1P, 2P, 3P and 4P versions.
Full current coverage
Rated current spans 1A, 2A, 3A, 4A, 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A and 63A, covering branch circuits from lighting to high-load appliances. Each rating is factory calibrated to its nominal value, so the breaker holds long-term thermal stability under continuous load. Select the exact rating for the downstream circuit instead of oversizing, which keeps nuisance tripping low and conductor protection accurate.
4kA and 6kA interrupting capacity
Both 4kA and 6kA breaking ratings are available. Match the rating to the fault level at the installation point to keep short circuit clearing within the breaker’s capacity. The arc-extinguishing chamber and contact system are sized for repeated clearing events, which protects downstream equipment and reduces panel damage during faults.
B, C and D trip curves
Trip characteristic B trips at 3 to 5 times rated current and suits resistive loads and cable protection. Characteristic C trips at 5 to 10 times rated current and covers general distribution. Characteristic D trips at 10 to 20 times rated current and handles motor and inductive loads with higher inrush. The thermal-magnetic mechanism uses a bimetal strip for overload detection and a magnetic coil for short circuit detection, so the two responses work independently across the full current range.
Poles and voltage configuration
The WTB1-63 ships in 1P, 2P, 3P and 4P configurations for 230V single-phase and 400V three-phase systems. Multi-pole versions break all live conductors simultaneously, which keeps downstream circuits fully isolated during maintenance and fault conditions.
Long service life
Mechanical lifespan reaches 20,000 operations and electrical lifespan 6,000 operations. The contacts are silver-alloy based for low resistance and stable performance in circuits that switch often, such as heating, lighting and motor control.
Installation parameters
Connecting capacity of 16mm² accepts standard copper conductors, connection torque of 2Nm secures terminations consistently, and protection level IP20 covers normal indoor mounting. Pollution degree 2 fits residential and commercial environments with non-conductive pollution only.
Isolation function
The breaker functions as an isolating device per IEC 60898-1, so the circuit can be manually disconnected for maintenance without a separate switch. The toggle mechanism provides clear ON/OFF indication for safe servicing.
Standards and certification
Compliant with IEC 60898-1 and GB/T 10963.1, certified by CCC and CE. Test reports cover dielectric strength, thermal and magnetic trip accuracy, and endurance under rated conditions.
Send your rated current, pole count, trip curve and breaking capacity requirements to request the matching WTB1-63 configuration and pricing.














