

What is the function of the NB4LE Residual Current Operated Circuit Breaker?
It protects people and electrical equipment by detecting and interrupting residual currents that may result from insulation failures, while also providing overload and short-circuit protection.
What types of electrical systems can the NB4LE be used in?
It’s suitable for TN and IT systems, handling both resistive and inductive loads such as lighting, HVAC, and industrial control circuits.
How does the Type F RCD version differ from Type A?
Type F offers enhanced protection by detecting mixed-frequency and DC residual currents up to 10mA, reducing nuisance tripping and ensuring better protection in circuits with electronic loads.
What is the rated short-circuit capacity?
The NB4LE has a 10kA breaking capacity, ensuring safe disconnection during fault conditions.
Can the NB4LE be used in high-temperature environments?
Yes — it operates reliably between −25°C and +70°C and includes temperature compensation for rated current to maintain performance under varying conditions.