Power® supply units (PSUs) are subcomponents of enclosures. A PSU takes electrical power and distributes the power to other components in the system.
Two PSUs are installed in control and expansion enclosures for redundancy. When the redundant attribute is yes, the PSU can be removed from the system without affecting the power supply to the enclosure. The PSU on the left side is called PSU 1. The PSU on the right is called PSU 2. For Lenovo Storage V7000 Gen1, PSU 2 is installed upside down. For Lenovo Storage® V7000 Gen2, PSU 2 is installed right side up.