Compact Circuit Protection

Jan. 2, 2008
Better, Faster, Cheaper. Smaller, Simpler, Better

There’s a corollary to the machine performance mantra “better, faster, cheaper” when it relates to the specification of electrical components in the electrical panel: Smaller, simpler, better. Shrinking the size of electrical panels, or increasing component density in existing cabinets are facts of life for machine builders.

The engineers at Cooper Bussmann extend this thinking with a new compact circuit protector (CCP) that incorporates the benefits of fusible overcurrent protection in a small footprint. It’s available in three different fusible variations: Class CC, 10X38, and DC. All versions have a 30 A or less rating, and are horsepower-rated for protection of motor and non-motor circuits.

“This is the smallest footprint available,” says Isabel Rochow, senior product manager at Cooper Bussmann. “At one-third the space required by a molded-case circuit breaker, and two-thirds the space required by a traditional fusible switch, the CCP saves space in your panel.”

CCP is DIN-rail mounted for ease of installation and has local and remote open-fuse indication for easier maintenance troubleshooting. “A positive visible circuit isolation via the disconnect lever is easy to read,” says Rochow, “and it’s designed finger-safe to IP20 standards to help prevent contact with live components.”

The company says the CCP-Class CC device’s 200 kA short-circuit current rating represents the highest possible SCCR. “It accepts only Class CC fuses,” says Rochow. “It rejects fuses with lower voltage and interrupt ratings.” She adds that the Class CC version meets NFPA 79 and UL508A requirements for use of 16AWG and 18AWG conductors, reducing wiring costs for these applications.

“The CCP-Class CC is very versatile since it’s the smallest, most-cost-effective UL98 branch disconnect with branch circuit-rated overcurrent protection,” says Rochow. “It can replace Class CC fuseholders with the added benefit of providing a disconnection means.” Rochow says it can be used to replace a UL508 disconnect/manual motor controller combined with fuses providing a load-break disconnect. “Compared to existing Class CC fusible disconnects, the CCP-Class CC has the same ratings and capabilities, but in a smaller size.”

Cooper Bussmann says the CCP can replace low-rated circuit breakers or misapplied supplementary protectors in branch circuit applications. “It provides a higher short-circuit rating at a similar or lower cost,” adds Rochow. “Compared to an equivalently rated industrial circuit breaker, it’s one-third the size.”

For control applications, UL508A requires protection of the control circuit by a branch circuit when control circuit transformers or power supplies are tapped from the feeder circuit. When tapped from the branch circuit, only supplemental overcurrent protection is required. “However, in both cases, the equipment SCCR can’t be higher than the interrupting rating of the control circuit overcurrent device,” says Rochow. “The CCP Class CC can be used in thes applications to provide cost-effective overcurrent protection, high interrupting rating and increased equipment SCCR. Where supplemental protectors and standard circuit breakers are used, the voltage rating and interrupting rating limits the application of equipment, unless more expensive circuit breakers with higher ratings are used.”

“Adherence to global standards ensures that the CCP can perform in panels installed in all markets round the world,” says Rochow.