1500 W TransZorb — what the ratings mean for the BOM
The 1.5KE180-E3/54: The 146 V reverse standoff voltage means the protected rail sits below this level during normal operation; the diode is effectively invisible until a transient exceeds that threshold.
Obsolete — sourcing and replacement path
Vishay lists the 1.5KE180-/54 as obsolete. A board-level functional replacement would require a parametric match on the 1500 W peak pulse, 146 V standoff, and 258 V clamping figures, in the same DO-201AA axial footprint. The through-hole DO-201AA (DO-27) package is a standard axial-lead form factor; the unidirectional single-channel layout simplifies polarity in the circuit — the cathode band marks the protected side. No pin-compatible second source is documented in the available records.