220 V standoff, 5 kW peak pulse — what that suppression window means
The 5KP220CA-HR: The 220 V reverse standoff is the continuous working voltage the protected rail can hold without the TVS conducting — in a 220 V nominal system that gives a few volts of margin before the device begins clamping. The 244 V minimum breakdown is where the Zener avalanche kicks in, and at 13.7 A peak pulse the clamping voltage tops out at 371.1 V. That 151 V overhead from standoff to clamping is the headroom the upstream switch or semiconductor must survive during the transient event. For a circuit running at 220 V line-neutral, this rating spread is the right-sized fit without needing to spec a higher standoff part that would cost more and clamp higher.
Power Line Protection is listed as No — this is a board-level TVS, not a service-entrance or distribution-panel surge protective device. It protects a single rail or signal line at the PCB level, not the AC line feed.
Axial P600 package and through-hole mounting
Tape & Reel packaging is listed, which is standard for high-volume assembly. Confirm the reel count per your pick-and-place feeder width and whether your contract manufacturer expects a specific orientation or polarity band on the leads — axial Zener polarity markings can be subtle on the body print.