Application-limited OCDs are always suitable for use in place of branch-circuit OCPDs. True or False?

• A. True
• B. False
• C. Only for deliberate loads
• D. Only when approved by the manufacturer

Answer: (B)

Protecting a branch circuit requires a device that reliably interrupts overcurrents and coordinates with the rest of the system. An application-limited overcurrent protective device is designed to operate within certain restricted conditions, and it cannot be assumed to provide full, reliable protection for a branch circuit in all fault scenarios. If you substitute it for a branch-circuit OCPD, you risk inadequate protection (for example, the device may not interrupt fast enough for a fault, or its interrupting rating may not cover the actual fault current available), or you may disrupt coordination with upstream devices. Manufacturer approval doesn’t automatically make such a substitution compliant with code or safe; the device must be explicitly rated and listed for that exact use, with proper coordination and conductor protection. In practice, this means it’s not always suitable to replace a branch-circuit OCPD with an application-limited OCD; use only when the ratings, installation instructions, and code requirements clearly allow it.