Alstom MCAG34VCBE0220A Busbar Protection Relay

Alstom MCAG34VCBE0220A is a high-impedance busbar protection relay from the MCAG34 family, engineered for fast, high-stability circulating-current protection of busbar configurations. This three-element relay, typically housed in a 30TE (size 6 inch) enclosure, delivers current-calibrated busbar differential protection suitable for high-voltage installations. The MCAG34VCBE0220A variant is specified for high-impedance busbar protection and is associated with 132 kV bus sections in substations and large switchyards. In Alstom/Areva/GE documentation, the MCAG34 family is described as providing high-stability circulating protection with a stabilizing resistor as part of its high-impedance scheme. Typical applications include protection of HV busbars in substations, turbine-generator interfaces, and other large power-system configurations where rapid fault isolation on the busbar minimizes disturbance to the wider network.