Eaton FH33 Bimetallic Thermal Unit 5.27 to 5.74 A

Eaton FH33 Bimetallic Thermal Unit

The Eaton FH33 is a bimetallic thermal overload unit rated for 5.27 to 5.74 amperes. It provides Trip Class 20 protection for motor starters in industrial control panels. This component suits maintenance engineers and panel builders replacing a worn unit in existing Eaton A200 or B100 series equipment.

Verify starter series and full-load current

Confirm the motor starter carries a NEMA Size 0, 1 or 2 rating and belongs to the Series A200 or B100 families listed in the compatibility data. The installed heater must match the motor’s full-load current, which falls between 4.4 and 4.87 amperes or 5.15 and 5.6 amperes for this unit. Cross-reference the Grainger part numbers 11Z488 through 11Z497 to ensure correct fitment before ordering.

Thermal trip behaviour and power dissipation

As a bimetallic device, the FH33 trips on sustained overcurrent rather than instantaneous spikes, allowing normal motor starting currents to pass. In normal operation the element runs warm but does not require forced airflow or produce audible noise. Power draw is limited to the heater’s own dissipation at the rated current, with no auxiliary supply needed.