What the 1500W rating means for your board
The 1.5KE30C: That 1500W figure tells you how much transient energy the part can absorb in a single pulse — not continuous dissipation. For a 36.7A peak pulse current, the diode clamps at 43.47V max, so a 24V rail sees the surge held under 44V before the TVS recovers. The reverse standoff voltage is 25.6V, meaning the diode stays off below that DC level and only starts conducting when the transient pushes above the minimum breakdown of 27V.
Obsolete — what that means for procurement
For existing BOM lines, the 1.5KE30C is available through independent surplus and broker channels. No pin-compatible direct replacement is documented by Littelfuse — a parametric search for a 1500W bidirectional TVS with similar standoff and clamping voltages will yield functional equivalents, but the DO-201 axial footprint and the exact breakdown window should be matched against the board's layout and protection margin.
The 1.5KE30C comes in a DO-201AA (DO-27) axial-lead package, through-hole mount. The DO-201 body is larger than the common DO-41 — it handles the 1500W pulse without overheating the junction.