An administrator is working with an electrician to design a new datacenter. The datacenter will have desktop PCs, phone switches, and racks of servers. Which of the following BEST describes the…

12V is an internal DC rail inside computer power supply units, not an external circuit an electrician provisions at the facility level.

24V DC is used in some building automation and industrial control systems but is not a standard power type for any of the equipment categories described.

48V DC is the industry-standard supply voltage for telephone switches and PBX systems - telecom equipment traditionally operates on -48V DC per ITU and TIA standards, making it a required power type for the phone switch infrastructure.

60V DC is not a standard voltage for servers, desktop PCs, or phone switches in a typical datacenter environment.

110V AC is the standard single-phase US electrical outlet voltage required by desktop PCs and general-purpose equipment, making it essential for the desktop PC portion of the datacenter.

220V AC (208V in practice for three-phase US installations) is used for high-power server rack PDUs and large UPS systems, providing more efficient power delivery for rack-mounted servers with dual power supplies.

440V is a three-phase industrial voltage used for heavy motors and large HVAC compressors, far exceeding the requirements for servers, PCs, or phone switches.