Section 4, Site Preparation - Electrical Considerations61186003L1-1D 4-3ELECTRICAL CONSIDERATIONSThe MX2820 shelf supports dual-feed –48 VDC or ±24 VDC power inputs.Power Wiring and FusingMX2820 power connections, including return connections, should be provided from the fusepanel using insulated wire and the appropriate fuse (see Table 2-7 on page 2-6). Per appli-cation requirements, power can be provided by a –48 VDC or ±24 VDC supply. A separate wireshould be run from the fuse panel for each –48 VDC or ±24 VDC input and for each VDCreturn. Power wire with red insulation is recommended for the voltage feeds, and power wirewith black insulation is recommended for the return feeds.NOTEApplications which include STS-1 multiplexers should be –48 VDConly.Fan Module PowerRefer to the appropriate Installation and Maintenance Practice and/or Job Aid for Fan instal-lation.Frame GroundEach MX2820 shelf requires a connection to frame ground using the appropriate AWG wiresize. See Table 2-7 on page 2-6.FOLLOW-UP PROCEDURESOnce the Central Office preparation described in this section of the manual is complete, theMX2820 shelves are ready for the installation. “NTP-001, Shelf and SCU Installation” providesthe instructions for installing the shelves.
