The breaker is rated at 400 A continuous current at 600 V AC (50/60 Hz) and has an interrupting capacity of 35 kA at 480 V AC. It also carries a 25 kA interrupting rating at 600 V AC. For DC applications, the HKD3400F can be used up to 250 V DC with appropriate derating.

Equipped with a thermal-magnetic trip unit, the HKD3400F provides inverse-time overload protection via the thermal element and instantaneous short-circuit protection via the magnetic element. The trip unit is adjustable for the magnetic pickup, allowing customization to specific load characteristics. Fixed thermal trip ensures reliable performance under overload conditions.

The breaker features a rugged molded case made of glass-reinforced polyester, offering high dielectric strength and resistance to impact. Line and load terminals accept copper or aluminum conductors. A wide range of field-installable accessories is available, including auxiliary switches, alarm contacts, shunt trips, and undervoltage release modules (such as the MTDUVR230V).

The HKD3400F is UL 489 listed and CSA C22.2 No. 5 certified, ensuring compliance with North American safety standards. It also meets IEC 60947-2 requirements, making it suitable for global projects. The breaker is marked for reverse feed operation, providing installation flexibility.

Common applications include main switchboards, distribution panels, motor control centers, and feeder circuits in commercial buildings and industrial plants. Its high interrupting capacity makes it ideal for systems with high available fault current.

The breaker measures approximately 10.5 inches (267 mm) in height, 5.5 inches (140 mm) in width, and 4 inches (102 mm) in depth. It can be mounted directly to a panel or used with a variety of plug-in bases and enclosures.