What the 1500W rating means on the bench
The 1.5KE47AG is a 1500W peak-pulse Zener TVS from Littelfuse's Mosorb™ series, in a DO-201AD axial package.
Littelfuse has marked the 1.5KE47AG as Obsolete.
Key ratings and what they mean for fit
Reverse standoff voltage is 40.2 V — the diode starts conducting above this level, so the protected rail must stay below 40.2 V in normal operation. Breakdown voltage (min) is 44.7 V, meaning the avalanche triggers between 44.7 V and the clamp voltage of 64.8 V. The 23.2 A peak pulse current (10/1000 µs) is the surge it can handle once; for repetitive events, derate per the datasheet's pulse derating curve. Operating temperature spans -65°C to 175°C, covering most industrial and automotive under-hood environments.