A moulded-case circuit breaker (MCCB) serving as the main isolating and over-current protection device for the elevator motor and drive power supply.
Full Definition
An elevator MCCB (Moulded Case Circuit Breaker) is a high-breaking-capacity switching device complying with IEC 60947-2, installed as the principal protective device between the building's electrical distribution and the elevator controller. Rated current typically ranges from 16 A to 250 A depending on motor power; breaking capacity is 25–50 kA at 400 V. Unlike an MCB, an MCCB offers adjustable over-current (Ir) and short-circuit (Im) trip settings, an integral rotary handle for the mandatory lock-off facility required by EN 81-20 §5.10.1.1, and auxiliary contacts for remote fault signalling to the BMS. In machine-room-less (MRL) configurations the MCCB is located in a dedicated cabinet at the topmost floor landing. Proper selectivity (discrimination) between the MCCB and downstream MCBs must be verified to ensure only the faulted circuit is isolated. Motor-protective MCCBs with electronic trip units allow setting of thermal memory and class 10/20 motor protection curves.
