1500 W peak pulse — what it means for the rail
The 1.5SMC27CA-M3/9AT: That 1500 W rating means the device can absorb a single 40 A surge (at the clamping voltage of 37.5 V) without failing — enough to protect a 24 V DC bus from an inductive load dump or a lightning-induced transient on a long cable run. Breakdown occurs at 25.7 V minimum, and clamping is specified at 37.5 V maximum — the rail sees no more than 37.5 V during the surge event.
Package and temperature grade
The wide temperature span covers both cold-start conditions in outdoor equipment and the self-heating from repetitive surge events within the pulse derating curve.