Motor power and speed are useful starting points, but you must translate them into torque at the brake location. First compute motor torque from power and speed, then apply the gearbox ratio and efficiency to estimate torque at the drum or shaft where the brake is mounted. For hoists, also consider load torque and reeving; motor torque alone may not reflect real holding requirements, especially during lowering.
Next, verify duty cycle and braking energy. A brake that meets torque requirements may still overheat if it must stop frequently or handle emergency dynamic stops. Confirm allowable stops/hour, permissible energy per stop, friction material limits, and cooling characteristics (disc vs drum).
Finally, consider installation constraints: shaft diameter, disc/drum size, mounting interface, and available space. For VFD systems, coordination between electrical braking and mechanical brake engagement is crucial to avoid shock loads or drifting. The best selection method is application-based: provide load, speed, inertia, and duty class—not just motor nameplate data.