Clamping voltage and protection margin
The 1.5KE170A-B clamps at 234V max at the 6.4A peak pulse current (10/1000µs waveform). That 234V ceiling is what the downstream circuitry must survive — if your DC bus sits at 145V nominal (the reverse standoff), the TVS starts conducting at the 162V minimum breakdown and holds the line below 234V through the surge.
Obsolete — sourcing through surplus channels
Diodes Incorporated lists this part as obsolete. The 1500W peak pulse rating and DO-201 axial footprint are the cross-reference anchors if you need to qualify a replacement.
Temperature range and board integration
The DO-201AA / DO-27 axial package (supplier device package DO-201) is a through-hole leaded form — the leads carry the surge current into the board, so the copper pad area and trace width to the protected rail need to handle the 6.4A peak without fusing.