11.2.4 Rack-mounted HMC Feature code FC 0083 provides a rack-mounted HMC.  The HMC is a 1U IBM server and an optional IBM 1U standard tray that features a monitor  and a keyboard. The system unit and tray must be mounted in the rack in two adjacent 1U  locations in the “ergonomic zone” between 21U and 26U in a standard 19-inch rack.  The customer must provide the rack or it can be installed in the 16U reserved space of the  z14 ZR1. Three C13 power receptacles are required: two for the system unit and one for the  display and keyboard, as shown in Figure 11-1. Figure 11-1 Rack-mounted HMC installed in an extra rack Chapter 11. Hardware Management Console and Support Elements  361