Cabling the Modular Switch

This section discusses the following topics:

Cabling the Power Supplies

Before you begin, refer to the Arista Networks document Compliance and Safety Guide, available at product-documentation.

 

Note: Power supplies may be loaded in the PSU bays in any order. The following order is recommended for each switch covered by this guide.

 

 

Table 1. Recommended PSU Bay Population Order
Switch Order
DCS-7804 8, 7, 6, 5, 4, 3, 2, 1
DCS-7808 6, 12, 5, 11, 4, 10, 3, 9, 2, 8, 1, 7
DCS-7812 9, 18, 8, 17, 7, 16, 6, 15, 5, 14, 4, 13, 3, 12, 2, 11, 1, 10
DCS-7816 8, 16, 24, 7, 15, 23, 6, 14, 22, 5, 13, 21, 4, 12, 20, 3, 11, 19, 2, 10, 18, 1, 9, 17

 

The following figure shows the recommended order. A blank (X) should be placed on all unpopulated bays.

 

Figure 1. Installation Sequence

Technical diagrams illustrating the PSU installation sequence for four models. Each diagram shows a rear view of the chassis with a numbered yellow arrow path indicating the zig-zag or horizontal order in which PSUs should be populated.

 

Note: '*' designates the recommended starting bay.

 

 

Important:

Power down the switch. Remove all power cords from the power inlets.

 

Mettez le commutateur: Retirez tous les cordons d'alimentation des prises d'alimentation.

 

 

Important:

The installation of this equipment must comply with local and national electrical codes. Consult with the appropriate regulatory agencies and inspection authorities to ensure compliance if necessary.

 

Installation de cet équipement doit être conformes aux codes électriques locaux et nationaux. Si nécessaire, consulter les organismes de réglementation appropriés et des autorités de contrôle pour assurer la conformité.

 

 

Note:

Many configurations will require additional power supplies.

 

Nombreuses configurations exigera des alimentations supplémentaires.

 

 

Important:

All power supply slots must be filled with either a power supply or blank to ensure proper airflow.

 

Tous les emplacements d'approvisionnement de puissance doivent être remplis avec une alimentation ou vide pour assurer un débit d'air appropriée.

 

 

Important:

Read all installation instructions before connecting the system to the power source.

 

Lire toutes les instructions d'installation avant de brancher le système à la source d'alimentation.

 

 

Power Supply Configurations show each switch's minimum number of operating power supplies connected to active circuits.

Each power supply includes a fan that maintains proper power supply temperature. The appendices display the location of components for all switches described in this guide.

Cabling Chassis Ground

Note: This section applies only to +48VDC input installations. A bonding wire from the chassis to the rack and/or the data center ground is optional for AC input installations.

Identify the location of the chassis grounding locations on the front panel of the switches. Additional grounding locations are on the rear panel of the switch chassis. After mounting the switch into the rack, connect at least one of the chassis grounds to the data center ground using two-hole ground lugs with 16 mm (5/8 in.) spacing and two M4 x 0.7 screws. After the switch is grounded, ESD wrist straps can be grounded by connecting them to one of the attach points.

 

Important:

Grounding wires and grounding lugs are not supplied. Wire size should meet local and national installation requirements. Commercially available 2 or 4 AWG wire is recommended for installations in the U.S.

 

À la terre et de mise à la terre fils cosses ne sont pas fournis. Calibre des fils doit satisfaire des exigences de l'installation locale et nationale. Disponible dans le commerce 2 ou 4 AWG fil est recommandé pour les installations aux États-Unis.

 

 

Important:

This equipment must be grounded. Never defeat the ground conductor. This unit requires over-current protection.

 

Cet équipement doit être mis à la terre. Ne jamais modifier le conducteur de terre. Cet appareil nécessite de protection contre les surintensités.

 

 

Important:

Secondary Grounding wires, lugs, and screws (M4 x 0.7) are not supplied.

 

Secondaire à la terre, câbles, cosses et vis (M4 x 0.7) ne sont pas fournis.

 

 

Figure 2. DCS-7804 Front Panel (Fully Populated)

A detailed technical diagram of the front panel of an Arista DCS-7804 modular switch chassis, illustrating the layout of supervisor modules, line cards, and power supplies.
 
1 ESD attach point 2 Grounding locations 3 Supervisor lock
4 Supervisor modules 5 Supervisor slot number 6 Linecard lock
7 Linecard 8 Linecard slot numbers 9 Extraction tool
10 Power supplies 11 Power supplies slot numbers    

 

Figure 3. DCS-7808 Front Panel (Fully Populated)

A technical diagram of the front panel of an Arista DCS-7808 modular switch chassis, detailing the vertical arrangement of management, data, and power components.
 
1 ESD attach point 2 Supervisor lock 3 Supervisor modules
4 Supervisor slot numbers 5 Linecard lock 6 Linecard
7 Linecard slot numbers 8 Power supplies 9 Power supplies slot numbers

 

Figure 4. DCS-7812 Front Panel (Fully Populated)

/assets/images/qsg/qsg-7800-series/Graphics/Cabling%20the%20Modular%20Switch/DCS-7812_Front.png
 
1 ESD attach point 2 Grounding locations 3 Supervisor lock
4 Supervisor modules 5 Supervisor slot numbers 6 Linecard lock
7 Linecard 8 Linecard slot numbers 9 Extraction tool
10 Linecard and Supervisor extraction tool tether 11 Power supplies 12 Power supplies slot numbers

 

Figure 5. DCS-7816 Front Panel (Fully Populated)

/assets/images/qsg/qsg-7800-series/Graphics/Cabling%20the%20Modular%20Switch/DCS-7816_Front.png
 
1 ESD attach point 2 Grounding locations 3 Extraction tool
4 Linecard and Supervisor extraction tool tether 5 Linecard lock 6 Linecard
7 Linecard slot number 8 Supervisor lock 9 Supervisor modules
10 Supervisor slot numbers 11 Linecard lock 12 Linecard
13 ESD attach point 14 Extraction tool 15 Linecard and Supervisor extraction tool tether
16 Power supplies 17 Power supplies slot numbers    

 

Figure 6. DCS-7816L Front Panel (Fully Populated)


 
1 ESD attach point 2 Grounding locations 3 Supervisor lock
4 Supervisor module 5 Supervisor slot numbers 6 Linecard lock
7 Linecard 8 Linecard slot numbers 9 Linecard lock
10 Linecard 11 Extraction tool 12 ESD attach point
13 Power supplies 14 Power supplies slot numbers    

 

 

Note: Remove all power cords from the power inlets to turn off the switch.

 

Cabling the AC Power Supplies

The switches use PWR-D1-3041-AC-BLUE (Figure 7) power supplies with SAF-D-GRID connectors on the PSU inputs. Power cables are included with the accessory kit (Table 1). To power the switch, insert the other side of the cable into the main power-providing circuit.

 

Note: The power supply, handle color, orientation, etc., may differ from the one shown on your device in Figure 7.

 

 

Figure 7. AC Power Supply

Close-up of a modular AC power supply unit. The image highlights the handle (blue indicating airflow direction), the latch release, and the status LEDs

 

The Front Panel displays the front panel location of the power supplies.

 

Note:
  • The LEDs on a PSU remain lit even after you disconnect the power and remove the PSU from the chassis. They will eventually turn off in a short while.
  • The PWR-D1-3041-AC-BLUE PSU uses 2x 220 V supply inputs and uses 2 APP SAF-D-GRID 400 connectors.

 

Cabling the DC Power Supply

Note:

The -48V and Battery-Return leads are a pair and should run adjacent and be approximately the same length.

 

Le - 48V et câbles de batterie-retour sont une paire courir à côté de l'autre et doivent être à peu près la même longueur.

 

DC Power Supplies

The switches support the PWR-D2-3041-DC-BLUE DC power supply displayed in Figure 8.

 

Figure 8. PWR-D2-3041-DC-BLUE Power Supplies

Front view of a DC power supply module. Numbered callouts identify the status output LED, release latch, input terminals (Input A and B), and ground terminal.

 

Note: Release lever color indicates airflow direction.

 

Wire and Lug Preparation

Remove power from DC circuits by turning off the power line servicing the circuits before installing. Prepare the stranded wiring before you begin a DC power installation.
  1. Stranded copper wiring is required.
    • Commercially available 1 to 2 AWG wire is recommended for installations in the U.S.
    • Wire size should meet local and national installation requirements.
    • Grounding wires and grounding lugs are not supplied.
    • Strip the wires to the appropriate length for the lugs.

       

    The wires connecting the DC power supply to the power source must meet the following requirements:

    • DC Input Wire Size: 1– 2 AWG.
    • Primary Ground Wire Size: 1– 2 AWG per power supply.
    • The conductors are copper.

       

  2. Use agency-approved compression (pressure) lugs for wiring terminations (2x - Two M6 studs with 5/8" spacing).
  3. Slip on heat-shrink tubing on the wire ends before assembling the lugs onto the wire.
    • The lugs must be crimped with the proper tool.
    • The tubing should extend over the lug’s barrel and the wire's insulator.

       

  4. Shrink the tubing with a heat gun.

     

    Figure 9. Lugs Wiring Terminations

    Detailed diagram of a heavy-duty DC power wire termination. Labels identify the insulated wire, heat-shrink tubing, and the dual-hole copper compression lug with 5/8-inch hole spacing.
     
    1 Insulated wire 3 Lug 5 Half-inch width
    2 Heat-shrink tubing 4 Quarter-inch diameter hole 6 Five-eighth-inch apart centers

Power Supply Specifications

The Table 2 shows the power supply specifications for each of the PSUs supported.

 

Table 2. Power Supply Specifications (each PSU)
Power Supply Maximum Output Power Rating (DC) Input Voltage and Frequency Maximum Input Current Input Branch Circuit Protection
PWR-D1-3041-AC-BLUE 3000 W 200 to 240 VAC(nominal) 50/60 Hz (nominal) 2x 16 A 2x 20 A
PWR-D2-3041-DC-BLUE 3000 W -48 V to -60 VDC, 70 A to 55A 2x 70 A 2x 90 A

 

 

Important:

Each power supply requires input branch circuit protection in compliance with AHJ requirements.

 

Chaque alimentation nécessite une protection du circuit de la branche d’entrée conformément aux exigences de l’AHJ.

 

Power Supply Configurations

The following table shows the power supply configurations for the modular switches.

 

Table 3. Power Supply Configurations
Modular Switch Number of PSUs Shipped in Bundle Maximum Number of PSUs Supported
DCS-7804 6 8
DCS-7808 8 12
DCS-7812 10 18
DCS-7816 12 24

 

Recommendations for Power Supply Usage

  • Use separate circuits (A and B) to protect each power supply.
  • When replacing a failed PSU, use the same PSU model. If the original model is no longer supported or available, an alternative PSU must be approved before use.
  • Only mix power supply types if your switch allows mixing power supplies.
  • To minimize distribution power loss, use an equal number of supplies in each row (e.g., 4 PSUs in slots 1-4 and 4 PSUs in slots 7-10 for a configuration with 8 PSUs for the DCS-7808 switch). Cabling the Power Supplies provides more details.

     

    Note: The DCS-7808 switch can house PSUs in either of two rows. The LEDs for PSUs in each row indicate correct status only after at least one of the PSUs in that row (PSU1 to PSU6 or PSU7 to PSU12) is energized from a power source. For the DCS-7812 and DCS-7816 switches, all PSU LEDs will report status correctly as long as one PSU is powered.

     

  • All power supply slots must be filled with a powered supply, a blank (X), or a non-powered power supply.
  • Valid redundancy configurations for each domain are described in Power Supply Redundancy.

     

Power Supply Redundancy

Important:

The installation of this equipment must comply with local and national electrical codes. Consult with the appropriate regulatory agencies and inspection authorities to ensure compliance if necessary.

 

Installation de cet équipement doit être conformes aux codes électriques locaux et nationaux. Si nécessaire, consulter les organismes de réglementation appropriés et des autorités de contrôle pour assurer la conformité.

 

 

Important:

Read all installation instructions before connecting the system to the power source.

 

Lire toutes les instructions d'installation avant de brancher le système à la source d'alimentation.

 

Most installations will have redundant, dual, independent power feeds. Each independent power feed will be referenced as A and B.

The recommended installation is to wire input_A and input_B of each supply to an independent power feed (A or B).

 

Note: When powered cables are connected to both A and B inputs of the PSU, the AC PSU will draw current from the A input. The B input is held in standby. The DC PSU will share power based on the input voltage.

 

Each power supply includes a fan that maintains proper power supply temperature. The appendices display the location of the components on all switches described in this guide.

The Front Panel displays the front panel location of the supervisor modules, linecards, and PSUs.

The Rear Panel displays the rear panel location of fabric modules.

 

Important:

This unit requires over-current protection.

 

Cet appareil nécessite de protection contre les surintensités.

 

 

Important:

Unused slots must be occupied or covered with a blank to ensure proper airflow through the chassis.

 

Les emplacements inutilisés doivent être occupés ou recouvert d'un blanc pour assurer la bonne circulation d'air dans le châssis.

 

Connecting Supervisor Cables

Supervisor modules contain console, management, and USB ports. Figure 10 display port and status LED locations on the supervisors. For additional information about the serial port, refer to the chassis specification in Figure 11.

 

Figure 10. Supervisor DCS-7800-SUP, DCS-7800-SUP1A, and DCS-7816-SUP

Faceplate view of the supervisor module. Numbered callouts identify the locking mechanism, status LEDs for system/linecards/fans, serial console port, USB ports, and Ethernet management ports.
 
1 Locking mechanism 5 Linecard status LED 9 RJ-45 Serial management port
2 Supervisor status LED 6 Fabric Module status LED 10 USB Ports
3 Supervisor active status LED 7 Fan status LED 11 RJ-45 Ethernet management port
4 PSU status LED 8 Clock In 12 SFP Ethernet management port

 

  • Console (Serial) Port: Connect to a PC with RJ-45 to DB-9 serial adapter cable. Default switch settings include:
    • 9600 baud
    • No flow control
    • 1 stop bit
    • No parity bits
    • 8 data bits

       

The appropriate supervisor cards must be installed in one of the designated slots. They are shown in Figure 11 for the DCS-7808 switch. For the DCS-7816 switch, the supervisor slots are in the middle of the chassis.

 

Figure 11. DCS-7808 Supervisor Slots

Front chassis diagram highlighting the two dedicated central slots where the supervisor modules must be installed for operation.
 
1 Power supplies 4 Linecards 7 Supervisor lock
2 Linecard and Supervisor extraction tool tether 5 Linecard lock 8 Grounding locations
3 Extraction tool 6 Supervisor modules 9 ESD attach point

 

RJ-45 to DB-9 Connections

 
RJ-45 DB-9 RJ-45 DB-9
RTS 1 8 CTS GND 5 5 GND
DTR 2 6 DSR RXD 6 3 TXD
TXD 3 2 RXD DSR 7 4 DTR
GND 4 5 GND CTS 8 7 RTS

 

  • Ethernet management port: Connect to 10/100/1000 management network with RJ-45 cable.
  • USB Port: This may be used for software or configuration updates.
  • Clock Input Port: The port type is MCX connector, 2-5.5V, 50 ohm termination.

     

Connecting Linecard Modules and Cables

Install required SFP, SFP+, QSFP+, QSFP100, OSFP, and QSFP-DD optic modules in linecard module ports (Figure 12).

 

Figure 12. SFP or SFP+ Ports

Front view of a linecard faceplate showing multiple rows of small form-factor pluggable (SFP) transceiver ports, each accompanied by an individual link status LED.

 

Figure 13. QSFP, QSFP+ and other Ports

Front view of a linecard faceplate showing multiple rows of small form-factor pluggable (SFP) transceiver ports, each accompanied by an individual link status LED.

 

Connect cables as required to linecard module ports. Supervisor and linecard module ejectors on the front of the chassis assist with cable management.

Note: When inserted in the correct orientation, optical modules will seat with a click. If you encounter resistance when inserting the optical module, remove it and rotate it before reinserting. .

 

Note: For more information about supported optical transceivers, refer to

https://www.arista.com/assets/data/pdf/Transceiver-Guide.pdf.

 

CAUTION:

Excessive bending can damage interface cables, especially optical cables.

 

Flexion excessive peut endommager les câbles d'interface, en particulier les câbles optiques.

 

 

Note: You must ensure that the appropriate “blank” plates cover any open slots for modules, power supplies, etc. Check with your local Arista Networks representative if you have questions.