Square D A1.54 480V 1.30-1.37A Circuit Breaker

Square D A1.54 Thermal Unit is a class 20 overload element designed to work with Square D contactors to provide motor overload protection in AC control circuits. The unit supports a motor full‑load current range of 1.28–1.37 A (with 480 V installations commonly cited around 1.30–1.37 A) and is rated for up to 600 VAC, with a 40°C ambient rating, making it suitable for typical industrial 480–600 V motor applications. This thermal unit is intended for use in Square D overload/thermal protection schemes and is not a standalone circuit breaker; it functions as the heating element in the overload relay that trips the contactor when excess current is detected. The A1.54 designation is widely cataloged for Square D overload protection, reflecting its role as a standard 20‑trip thermal unit selected based on the motor’s FLC and the supply voltage.