Surge protection fit — what the voltage numbers mean for the rail
The 1.5KE24CA-E3/54: Breakdown starts at 22.8 V minimum, and the clamping voltage peaks at 33.2 V when the full 45.2 A surge current flows (10/1000 µs waveform). That 33.2 V clamp is what the downstream circuitry must survive. The bidirectional construction means polarity doesn't matter — one device protects both positive and negative-going spikes on the same line.
The TransZorb® series is a long-running catalog line, so supply continuity is predictable. The base product number 1.5KE24 covers both unidirectional and bidirectional variants; the "CA" suffix marks this as the bidirectional version. The -/54 suffix indicates the lead-free (RoHS-compliant) finish and the tape-and-reel packaging for automated insertion.