10 Arista Networks Copyright 2014
Chapter 4: Powering the Switch
4.2 Cabling the DC Power Supply (DCS-7010T-48-DC)
Figure 7 displays the location of the earth grounding pad and the DC input terminals.
Figure 8 displays DC power terminals on the left side of the rear panel with the terminal cover in place
(left illustration) and with the terminal cover removed (right illustration).
Important! Grounding lugs for the earth grounding pads and grounding wires are not supplied. M4 screws are
required. Wire size should meet local and national installation requirements. Recommended
grounding wire sizes are 6 AWG (earth ground) and 16 AWG (PE ground). M4x0.7 screws are required
to secure the wire to the grounding pads. Screws are pre-installed for the PE ground terminals.
Each DC input terminal accepts insulated crimp-on spade lugs, insulated crimp-on ring connectors, or
bare wires. Ensure the wires connecting the DC power supply to the power source meet the following:
• DC Input Wire Size: 14 AWG (1.5 mm2) to 18 AWG (0.75 mm2)
• PE Ground Wire Size: 14 AWG (1.5 mm2) to 18 AWG (0.75 mm2)
• Wire Terminal (Lug): ring or spade, 14-16 AWG, #6 / M3.5 screw
• Overcurrent protection: 20 A.
Important! Wire size must comply with local and national requirements and electrical codes. Use only copper wire.
DC power supplies require 40 – 72 VDC (absolute voltage) and draws 1.8 – 1.0 A. The power supply has
reverse polarity protection.
Important! Before performing any installation actions, ensure power is removed from DC circuits by turning off
the power line circuits on DC power lines servicing the circuits.
Apply the ground connection first during installation and remove last when removing power.
To connect a DC power supply to a power source:
Step 1 Attach the secondary grounding pad to the Data Center ground (Figure 7).
Step 2 Remove the terminal cover to expose the connectors (Figure 8).
Step 3 Attach the appropriate lugs to the source DC wires.
Step 4 Connect the DC-input wires to the terminal block in this order:
1. Ground cable to the PE Ground connector on the terminal block.
2. Negative (–) source DC cable to the negative (–) connector on the terminal block.
3. Positive (+) source DC cable to the positive (+) connector on the terminal block.
Step 5 Replace the terminal cover.
Figure 7: DC Input Terminals and DC Grounding Pad
Figure 8: DC Input Terminals – terminal cover in place (left); terminal cover removed (right)
