Eaton FH34 Thermal Unit Trip Class 20

Eaton FH34 Thermal Unit

The Eaton FH34 thermal unit provides overload protection for motor starters with a Trip Class 20 rating. It suits maintenance teams and panel builders who need to match the thermal element to specific full-load current ranges of 4.88 to 5.3 A or 5.7 to 6.2 A. The transparent housing allows visual inspection of the element condition. It is designed for NEMA Size 0, 1 and 2 starters.

Compatibility Range

This thermal unit fits Series A200 and B100 motor starters across multiple configurations. It replaces elements identified by Grainger part numbers 11Z488 through 11Z497 and matches manufacturer models including B100J, B100M, B100S, B100U and B100W series with various suffix codes. Selecting the correct unit ensures the starter trips at the intended overload threshold. Buyers using non-listed starter series or current ranges outside the specified bands cannot use this unit.

Current Capacity and Headroom

The unit covers two distinct current bands: 4.88 to 5.3 A and 5.7 to 6.2 A at full load. Within these ranges the thermal element provides reliable overload tripping per Class 20 timing. Operation outside these bands will cause nuisance tripping or failure to protect the motor. The gap between 5.3 A and 5.7 A is not covered by this model. Installers must verify the motor nameplate current falls inside one of the two stated ranges before fitting.