© 2012 Harmonic Inc. 52 Electra 1000, Version 3.0, Rev MAppendix EWiring the –48 VDC Power SupplyIf your encoder has the optional –48 VDC power supply, follow these steps to wire the powersupply. Figure E-1 shows the DC power supply, which is located on the back panel.Figure E-1: DC power supplyE.1 Getting StartedBefore you begin wiring the –48 VDC power supply, make sure that you provide thenecessary overcurrent protection, wires, and power connector.E.2 Power Source SpecificationsThe DC power source feeding the encoder must meet the following requirements: Electrically isolated from any AC power source. Positive ground. The Positive bus of the DC power source must be reliably connected tothe Ground bus.Each feed-pair must provide a continuous supply of power that meets the specificationsshown in Table E-1.E.3 Overcurrent ProtectionTo provide overcurrent protection: Provide overcurrent protection devices as part of each rack housing encoders. Locate a readily accessible disconnect device between the DC power source and theencoder. Use a 10-amp double-pole fast trip, DC-rated disconnect device for each DC powerconnector.NOTE: Overcurrent protection devices must meet applicable national and local electrical safety codesand be approved for the intended application.Table E-1: DC Power Source RequirementsParameter SpecificationVoltage 40 to 60 VDCMax operating current 8 ampsMax input surge current 20 amps
