HNB1L-63 1P+N Residual Current Circuit Breaker

It is a single-phase DIN-rail RCCB that provides earth-leakage protection for 230 V domestic and light-commercial final circuits. Its 1P+N pole configuration switches phase and neutral together, and it is typically used as a group RCD feeding multiple MCB-protected circuits such as sockets, lighting and kitchen/utility circuits.

A toroidal zero-sequence current transformer monitors the vector sum of current in L and N. When no fault exists, the sum is zero. If a person touches a live part or insulation degrades, some current flows to earth, producing a small residual current. When this exceeds the rated sensitivity (commonly 30 mA), the internal release opens the contacts in milliseconds, interrupting the shock path before ventricular fibrillation can occur.

No — this is a pure RCCB. It will not trip on overload or short circuit, so it must be installed upstream of, or in combination with, MCBs that protect the wiring against overcurrent. For a self-contained single-circuit solution, use an RCBO variant instead.

The 1P+N configuration is rated for single-phase 230 V (50/60 Hz) systems. The HNB1L-63 family is built around a 63 A frame size, so continuous current capability is typically up to 63 A; the exact In, sensitivity (IΔn) and type (AC/A) must be read from the product nameplate. Size the upstream cables and MCBs to the actual load.

30 mA is the standard for personal protection on socket outlets and accessible circuits. 10 mA is used in special locations such as bathrooms and saunas, while 100–300 mA may be used upstream for fire protection. Do not select a higher sensitivity just to stop nuisance tripping without diagnosing the cause.

Type AC trips on pure sinusoidal AC leakage only. Type A also detects pulsating DC leakage produced by washing machines, dishwashers, induction hobs, inverter air conditioners, LED drivers and TVs. Because most modern homes contain such electronics, Type A is generally recommended; Type AC is increasingly unsuitable.

Mount on a 35 mm DIN rail. Connect the supply L and N to the line-side (top) terminals and the protected load to the load-side (bottom) terminals, observing L and N markings. The neutral must pass through the device; never bypass it, and keep neutrals of different RCCB groups separate. Tighten to the manufacturer's torque and verify before re-energizing.

Random or moisture-related tripping usually indicates degraded insulation somewhere downstream, often in damp junction boxes, outdoor sockets, garden circuits or aging cabling. Isolate circuits and appliances one by one, and measure insulation resistance with a tester. If you cannot locate the fault, call a qualified electrician; do not reset and ignore repeated trips.

In most countries, installation and commissioning of permanent wiring must be carried out by a qualified electrician who can verify correct polarity, earthing, cable sizing and test results (loop impedance, RCD trip time, insulation resistance). Even where DIY is permitted, the commissioning tests are essential to ensure the device will actually protect people.

Press the front-panel "T" button once a month; the unit must trip immediately. Periodic inspection by an electrician should include a functional RCD test at 1× and 5× IΔn to confirm tripping current and time. If the test button does not trip the device, or if the unit has visible damage or corrosion, replace it promptly rather than continuing to rely on it.