An RCCB (Residual Current Circuit Breaker) typically does not trip in response to a voltage drop. The primary function of an RCCB is to detect imbalances between the live and neutral wires, which indicate leakage current potentially caused by faults such as insulation failures or a person coming into contact with a live wire. Voltage drop itself does not create an imbalance between live and neutral currents, so it would not cause the RCCB to trip.
An RCCB does not trip on low voltage. Its operation is based on detecting the difference in current between the live and neutral wires, not on the absolute voltage level. If the voltage drops but there is no current imbalance, the RCCB remains in its normal state. However, if the low voltage condition is accompanied by a fault that causes an imbalance, the RCCB will trip as designed to protect against electrical hazards.
An RCCB can trip due to various reasons, primarily when it detects a current imbalance that suggests leakage to earth. Common causes include faulty appliances, damaged wiring, or insulation faults. Additionally, moisture ingress or a person coming into contact with live parts can also lead to leakage currents, causing the RCCB to trip. The RCCB is sensitive to very small differences in current (typically 30 mA or less), making it effective for preventing electric shocks and fire hazards due to earth faults.
An RCCB does not trip on overvoltage. Overvoltage conditions are typically managed by different protective devices, such as surge protectors or overvoltage protection relays. The RCCB is solely concerned with detecting current imbalances between the live and neutral conductors. Even if the voltage increases beyond the normal operating range, as long as there is no leakage current creating an imbalance, the RCCB will not trip. Other circuit protection measures are necessary to safeguard against overvoltage.