What the 1500W rating actually protects
The 1.5SMC100AHE3/9AT: The 85.5V reverse standoff voltage means it sits across a nominal 85V rail without conducting, then breaks down at 95V minimum to shunt the surge to ground before it reaches downstream ICs. For a 24V automotive system with a 60V load-dump transient, this diode catches the spike well before it reaches the 100V breakdown of downstream MOSFETs. Single unidirectional channel means it protects one polarity — install it with the cathode toward the positive rail and anode to ground. No power line protection means it is intended for signal or low-voltage power rails, not mains AC inputs.
Package and temperature range — field-fit check
DO-214AB (SMC) is a standard surface-mount package with a JEDEC footprint. The cathode band is clearly marked on the body — orientation is unambiguous for pick-and-place or hand rework. No special handling beyond standard ESD precautions is needed; the package is moisture-sensitive but typical bake times are short at 125°C. The 150°C TJ(max) gives margin above the 125°C ambient typical in engine compartments.