Specifications

14 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E
AC-Powered Units
AC-powered radios are designed to operate from 115 to 230 Vac
(50-60 Hz). The supply will automatically adjust to match either stan-
dard voltage. However, the supply voltage must be between 90 and 132
Vac, or 180 to 264 Vac. Operation outside these two ranges may cause
damage to the power supply. A North American-style AC power cord is
supplied with these units. See Figure 13, “. Master Station Rear Panel,”
on page 18 to see the AC power supply module’s receptacle and switch.
DC-Powered Units
Internal Units Figure 9 shows a rear view of in internal DC power supply. Connection
to the power supply is made with a three-conductor plug-in terminal
strip. The radio can be operated in either a positive or negative-ground
configuration. The center pin of the chassis connector is not connected
within the radio.
Invisible place holder
Figure 9. Rear View of Master Station, DC Power Input
External Units
External DC-power supplies are available as a standard option. Two
DC-to-DC power inverters are provided on a open rack shelf. Each
inverter is protected from dust and debris by a clear plastic cover.
Invisible place holder
Figure 10. Typical Rack-Mounted External DC Power Supply
(with dual supplies)
ON/OFF SWITCH
DC POWER INPUT