1500 W TransZorb — what the ratings mean for the BOM
The 1.5KE120C-E3/54: The 97.2 V reverse standoff voltage means it stays transparent on a nominal 96 V bus, while the 108 V minimum breakdown ensures the avalanche triggers before the line sees damaging overvoltage. Clamping at 173 V max with an 8.7 A peak pulse current — the TVS absorbs the surge and holds the downstream components below their voltage rating. The DO-201AA (DO-27) axial package is through-hole — it sits in a drilled PCB hole and solders on the opposite side, common in industrial and telecom board layouts.
Obsolete — sourcing through independent channels
Vishay lists the 1.5KE120C-/54 as Obsolete. No pin-compatible direct replacement from Vishay is published; a functional substitute would require verifying the standoff and clamp voltages match the protection threshold.