What the 1500W peak pulse rating means on a real board
The 1.5KE30A-E3/73: The 1.5KE30A-/73 is a 1500W (1.5kW) unidirectional TransZorb® TVS diode in a DO-201AA axial-leaded package — the classic through-hole form factor that survives a soldering iron and can be swapped on site without a hot-air station. Reverse standoff voltage is 25.6V, so it sits across a 24V nominal rail and stays out of conduction until the transient pushes above the 28.5V minimum breakdown threshold — no leakage penalty at the operating voltage.
Where it fits and where it does not
Power line protection is marked 'No' — this is not a primary AC mains suppressor. It belongs on DC power rails, signal lines, or low-voltage bus bars where the 25.6V standoff matches a 24V bus. The axial DO-201AA body is polarity-marked with a cathode band — orientation is obvious enough to get right once, even without a bench. Snip the leads, insert, solder.
Lifecycle status is Active — Vishay still manufactures this part. Available in Cut Tape and Tape & Box packaging — the TB option suits hand-insertion or selective-solder lines where reel-fed is not needed.