Eaton AE16KNS0AB Bimetallic Thermal Overload Relay

The Eaton AE16KNS0AB (formerly Cutler-Hammer) is a bimetallic thermal overload relay designed for motor protection in industrial control systems. It provides adjustable current settings, manual or automatic reset, and reliable protection against overload phase loss. This NEMA-rated device is typically used with Eaton A200 series contactors or other motor starters.

Adjustable Current Range

The AE16KNS0AB covers a current adjustment range from 1.4A to 2.3A (full scale). The dial is calibrated in amps, with a trip class rating of 20 (standard). The bimetallic elements respond to motor heating, providing inverse time delay protection. Phase loss sensitivity ensures tripping in case of single phasing.

Reset Mechanism

The unit features a selectable manual/auto reset mode via a front switch. In manual reset mode, the operator must press the red reset button after a fault. In auto mode, the relay resets automatically when the bimetals cool down (approx 2 minutes). The reset button also acts as a stop button when pressed under normal operation.

Electrical Ratings

Rated insulation voltage: 600V AC. AC-15 contact rating: 240V at 5A; 600V at 2A. The auxiliary contact block (included) provides one normally open (NO) and one normally closed (NC) contact for interlocking into control circuits. The relay can directly control motor starters up to 1.5kW at 480V.

Physical and Environmental

Dimensions: 76 x 55 x 68 mm (H x W x D). Weight 0.25 kg. Terminals are screw-type with wire range 14-8 AWG. Operating temperature: -20°C to 60°C. The housing is impact-resistant thermoset with IP20 protection. It mounts directly onto the contactor or separately on a panel.

Standards and Certifications

Complies with NEMA ICS 2, UL 508, CSA C22.2 No. 14, and IEC 60947-4-1. CE marked. The bimetallic construction is inherently ambient temperature compensated.

Typical Applications

Used for overload protection of fractional horsepower motors, pumps, fans, conveyors, and compressors. The AE16KNS0AB is common in legacy Cutler-Hammer motor control centers and standalone starters.

Installation Notes

Ensure that the current setting matches full load current of the motor. For automatic reset mode, use caution to prevent automatic restarting of machinery. The relay should be protected from dust and water.

Conclusion

The Eaton AE16KNS0AB bimetallic overload relay provides adjustable, reliable motor protection. Its dual manual/auto reset capability and robust construction make it suitable for a wide range of industrial motor control applications.