What the 1500W rating means for your rail
The 1.5KE12CA/B: The 10.2V reverse standoff voltage and 11.4V minimum breakdown set the operating window: a 12V nominal rail stays protected, with clamping at 16.7V when the surge hits.
Package and board-fit realities
Bidirectional single-channel configuration means the same device clamps both polarities — no need to series two unidirectional parts for AC-coupled or bipolar rails.
Sourced to order against your BOM quantity through independent distribution channels.