What the 1500 W peak-pulse rating means for the BOM
The 1.5KE20HE3/73: The 29.1 V clamping voltage is the ceiling a downstream 24 V bus or 28 V tolerant input sees during a surge — if the protected device's abs-max rating sits below that, the TVS alone does not guarantee survival without additional series impedance.
Automotive grade and deployment envelope
The DO-201AA axial-lead through-hole package (also known as DO-27) is a standard footprint for 1.5 kW TVS diodes — the lead bend and board-mount hole pattern are consistent across the 1.5KE series, so a replacement from the same family drops into the same PCB layout without a board spin.