1500 W bidirectional TVS in an axial-lead package
The 1.5KE110C-E3/73: It clamps transients at 158 V max with a 9.5 A peak pulse current rating, and its 89.2 V reverse standoff voltage means it stays out of the way on a nominal 72–80 V rail. This is a single-channel Zener-type suppressor in a through-hole DO-201AA (DO-27) axial package — a footprint that's been a workhorse in telecom rectifiers, industrial power supplies, and motor-drive snubber circuits for decades.
Obsolete — sourcing through independent channels
Vishay lists the 1.5KE110C-/73 as obsolete. For a BOM line that calls out this exact part number, the supply path runs through independent surplus and broker inventory.
What the ratings mean for the protection decision
The 89.2 V reverse standoff voltage is the DC or peak-AC operating level below which the diode draws negligible leakage — it won't clip a 72 V nominal bus. The 99 V minimum breakdown voltage is where conduction starts, and the 158 V max clamping voltage is the peak the protected circuit must survive at 9.5 A Ipp. The 1500 W rating at 10/1000 µs is the standard telecom surge waveform; for shorter pulses (8/20 µs) the peak power capability is higher.