What the 1500 W rating means on a TVS diode
The 1.5KE170A-E3/73: The 145 V reverse standoff voltage means it sits across a 130–145 V rail without conducting leakage current; the 162 V minimum breakdown triggers clamping at the first transient that exceeds the rail tolerance. The 175 °C maximum junction temperature gives thermal headroom for repetitive surges in a 85 °C ambient panel.
Package and board-fit realities
DO-201AA (DO-27) axial-lead package, through-hole mount. The body is 9.1 mm long with 25.4 mm lead spacing — it stands off the board on its own leads, so the pad layout is two plated holes spaced 0.400 inch apart. The axial body has a cathode band; orientation matters for the unidirectional channel. Lead bending for horizontal or vertical mounting is common in point-to-point wiring or terminal-block assemblies. Tape & Box (TB) packaging means the parts are taped on a reel but shipped in a box rather than a standard reel — the lead form is straight for auto-insertion, but the box format is less common than tape-and-reel for axial diodes. Confirm the feeder compatibility if using a radial/axial inserter.