The 1.5KE20CA-E3/54: Minimum breakdown voltage is 19 V; the device begins to avalanche at that point and clamps the transient to 27.7 V. For a 24 V bus, the 17.1 V standoff is below the rail, so the TVS does not load the line in steady state. The 1500 W rating at 10/1000 µs is the peak pulse capability — sustained power is much lower, but for short overvoltage events this handles the energy without the junction exceeding the 175°C maximum operating temperature. The bidirectional channel (one device) protects both polarities, making it suitable for AC signal lines or DC rails where reverse connection is a risk.
Package and board integration
Through-hole DO-201AA (DO-27 axial) package, supplier device package 1.5KE. The 1.5KE footprint is standard across the series — if the board already uses a 1.5KE part, this drops in without layout changes.