Eaton's main circuit breakers are part of the main service modules used as service entrance equipment and housed in a rainproof enclosure. Eaton offers both main fusible switch and main circuit breaker group metering mains with busway connections allowing you to have multi-tenant metering in high-rise apartment buildings where riser busway is used. Select 3-phase, 400 200A main circuit breakers or 3-phase, 400 800A main fusible switches with aluminum or copper bus.