What the 1.5KE75-E3/73's clamping specs mean for your rail
That 109 V clamp ceiling protects downstream semiconductors rated for 100–120 V — if your downstream FETs or controller ICs have a Vds/Vcc max below 109 V, this part won't hold the rail. The 1500 W rating is a 10/1000 µs waveform peak — real-world transients (e.g., inductive kick from a 24 V relay bank or a load-dump on a 48 V telecom bus) are shorter and lower energy, so the part typically survives well beyond the 1.5 kW mark in practice.
The DO-201AA axial package is common across the entire 1.5KE series — a parametric match (same standoff, same clamp, same 1500 W rating) from a different series or brand may drop in if the lead bend and body length match.
Through-hole axial — board-fit realities
DO-201AA (DO-27) axial leaded package — the body is 9.1 mm long, leads are 1.3 mm diameter tin-plated copper. It mounts through a 1.1 mm hole; the lead bend radius must clear adjacent components.