The Eaton TF42-20 is a 3-pole thermal bi-metallic overload relay rated for 16 to 20 amps, adjustable via the dial. The relay is designed for use with AF Series contactors in the AF9 through AF38 frame sizes, so it bolts directly onto those contactor bodies without extra brackets.
Integration with AF contactors
This relay mounts directly to the output side of AF9 through AF38 contactors. The thermal element senses motor current through the contactor's power poles, so no separate current transformers are needed. Selectable manual or automatic reset — set it to auto for remote restart applications or manual for attended machinery where you want an operator to acknowledge the trip before restarting.
The 16-20 A adjustable range covers motors drawing between roughly 7.5 and 10 HP at 460 V three-phase. Trip Class 10 matches the starting characteristics of most general-purpose induction motors — compressors, pumps, fans. The NEMA type designation means the overload relay follows NEMA ICS 2-322 mounting and performance standards, which is the common spec for North American industrial control panels. The A-Line family shares the same form factor as other Eaton A-Line components, so the visual lineup in a panel stays consistent.