What the 1500 W rating means for your rail
The 1.5KE12A-G: That 1.5 kW rating tells you the device can absorb a transient of that energy without failing — but the real clamp voltage is 16.7 V maximum at 89.82 A peak pulse current. For a 12 V nominal rail, the 10.2 V reverse standoff voltage means it stays out of the circuit during normal operation and only conducts when the transient exceeds the 11.4 V minimum breakdown threshold.
Housed in a DO-201AA / DO-27 axial-lead through-hole package (supplier device package DO-201), this part mounts through a hole in the board and is wave-solderable. The axial leads handle the thermal cycling of the 1.5 kW pulse — the lead frame carries the heat to the board copper, so the PCB pad area and trace width to the protected rail matter more for surge survival than the package itself. No power line protection (it is a standalone TVS, not a filtered suppressor), so place it as close as possible to the transient entry point — connector or power input — to minimise loop inductance between the diode and the protected IC.