Circuit Breakers

Molded case circuit breakers are typically mounted in a circuit breaker enclosure directly attached to the alternator.

• The circuit breaker box may house single or multiple circuit breakers depending on the application requirements.
• Circuit breaker boxes may be top-entry or bottom-entry and must be large enough to accommodate large cables and provide adequate ventilation.
• Skid-mounted circuit breaker enclosures help reduce vibration stresses at the electrical connections and may also reduce cable bending requirements.
• Circuit breaker enclosures are available in General Purpose (Type 1), Dustproof (Type 12), and Rainproof (Type 3R) options.
• Dimensional drawings are available for all MTU Onsite Energy generator sets showing circuit breaker box locations and stub-up requirements for making the electrical connections.

Selecting the right circuit breaker depends on the nature of the application.

• Standard breakers provide reliable operation for the protection of the generator set.
• In life safety applications, continuity of service is critical and selectivity, or only tripping the relevant circuit breaker, heightened reliability, and regular testing may be required.
• Mission critical applications require continuity of service with maximum reliability, redundancy, and compliance with regulatory requirements.
• Grid parallel applications and prime power applications require maximum reliability and availability with enhanced safety for operators and utility workers.
• Mobile generator applications, such as those used on job sites or for emergency response, require rugged construction, tolerance for diverse loads, and maximum safety for workers and passersby.