netbox-community-netbox/docs/models/dcim/powerport.md

Power Ports

A power port is the inlet of a device where it draws its power. Power ports are upstream-facing towards power outlets. Alternatively, a power port can connect to a power feed – as mentioned in the power feed section – to indicate the power source of a PDU's inlet.

!!! info If the draw of a power port is left empty, it will be dynamically calculated based on the power outlets associated with that power port. This is usually the case on the power ports of devices that supply power, like a PDU.