Clamping voltage and breakdown — the fit check
The 1.5KE56CA R0G: Reverse standoff voltage is 47.8 V, meaning the diode stays off below that rail voltage. Breakdown starts at 53.2 V minimum, and clamping is held to 77 V maximum at the 20 A peak pulse current. For a 48 V nominal bus, this part clamps the surge well below the downstream components' abs-max rating.
Package and mounting — DO-201 axial leaded
Supplied in a DO-201AA (DO-27) axial-lead package, through-hole mount. The DO-201 body is the standard footprint for 1500 W TVS diodes — the lead spacing and body diameter match the common PCB hole pattern, and the axial leads handle the thermal cycling of repeated surge events better than a surface-mount package of the same power class.