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Connecting the EX4300 to Power

Connect Earth Ground to an EX Series Switch

To ensure proper operation and to meet safety and electromagnetic interference (EMI) requirements, you must connect an EX Series switch to earth ground before you connect power to the switch. You must use the protective earthing terminal on the switch chassis to connect the switch to earth ground (see Figure 2).

You must install the EX Series switch in a restricted–access location and ensure that the chassis is always properly grounded. EX Series switches have a two–hole protective grounding terminal provided on the chassis. See Table 1 for the location of the earthing terminals on various EX Series switches. Under all circumstances, use this grounding connection to ground the chassis. For AC-powered systems, you must also use the grounding wire in the AC power cord along with the two-hole grounding lug connection. This tested system meets or exceeds all applicable EMC regulatory requirements with the two-hole protective grounding terminal.

Ensure that a licensed electrician has attached an appropriate grounding lug to the grounding cable you supply. Using a grounding cable with an incorrectly attached lug can damage the switch.

Parts and Tools Required for Connecting an EX Series Switch to Earth Ground

Before you begin connecting an EX Series switch to earth ground, ensure you have the parts and tools required for your switch.

Table 1 lists the earthing terminal location, grounding cable and lug specifications, and parts needed for connecting an EX Series switch to earth ground.

Table 1: Parts Required for Connecting an EX Series Switch to Earth Ground

Switch

Earthing Terminal Location

Grounding Cable Requirements

Grounding Lug Specifications

Screws and Washers

Additional Information

EX2200

Rear panel of the chassis

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCC10-14BWL or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

  

EX2300-C

Rear panel of the chassis

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCC10-14AW-L or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

  

EX2300

Rear panel of the chassis

  • EX2300 switches except EX2300-24MP and EX2300-48MP models—14 AWG (2 mm²), minimum 90°C wire, or as permitted by the local code

  • EX2300-24MP and EX2300-48MP models—14-10 AWG STR (2.5-6 mm²), 12-10 AWG SOL (4-6 mm²) minimum 90°C wire, or as permitted by the local code—not provided

  • EX2300 switches except EX2300-24MP and EX2300-48MP models—Panduit LCC10-14AW-L or equivalent—not provided

  • EX2300-24MP and EX2300-48MP models—Panduit LCA10-10L or equivalent—not provided

  • EX2300 switches except EX2300-24MP and EX2300-48MP models

    • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

    • Two #10 flat washers—not provided

  • EX2300-24MP and EX2300-48MP models

    • One Pan Phillips M 4 x 6 mm Nickel plated screw—provided

  

EX3200 and EX3300

Rear panel of the chassis

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCC10-14BWL or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

For EX3200 Switches, see Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch.
EX3400

Rear panel of the chassis

14-10 AWG STR (2.5-6 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCD10-10A-L or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

  

EX4200

Left side of the chassis

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCC10-14BWL or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

See Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch.

EX4300 switches except EX4300-48MP and EX4300-48MP-S switches

Rear panel of the chassis

14-10 AWG STR (2.5-6 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCD10-10A-L or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

  

EX4300-48MP and EX4300-48MP-S switches

Rear panel of the chassis

14-10 AWG STR (2.5-6 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCD10-14B-L, LCC10-BW-L, or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

  

EX4500 and EX4550

Left side of the chassis

14 AWG (2 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCC10-14BWL or equivalent—not provided

  • Two 10-32 x .25 in. screws with #10 split-lock washer—not provided

  • Two #10 flat washers—not provided

See Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch.

EX6210

Rear panel of the chassis (on lower left side)

The grounding cable must be the same gauge as the power feed cables and as permitted by the local code.

Panduit LCD2-14A-Q or equivalent—provided

  • Two ¼ -20 x 0.5 in. screws with #¼” split-washer—provided

  • Two #¼” flat washers—provided

  

EX8208

Left side of the chassis

6 AWG (13.3 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCD2-14A-Q or equivalent—provided

  • Two ¼ -20 x 0.5 in. screws with #¼” split-washer—provided

  • Two #¼” flat washers—provided

  

EX8216

Two earthing terminals:

  • Left side of the chassis

  • Rear panel of the chassis

Note:

You must use only one of the two protective earthing terminals.

2 AWG (33.6 mm²), minimum 90° C wire, or as permitted by the local code

Panduit LCD2-14A-Q or equivalent—provided

  • Two ¼ -20 x 0.5 in. screws with #¼” split-washer—provided

  • Two #¼” flat washers—provided

  

EX9204, EX9208, and EX9214

Rear panel of the chassis

One 6 AWG (13.3 mm²), minimum 90° C wire, or one that complies with the local code

Thomas& Betts LCN6-14 or equivalent—provided

  • Two ¼ -20 x 0.5 in. screws with #¼” split-washer—provided

  • Two #¼” flat washers—provided

See Grounding Cable and Lug Specifications for EX9200 Switches.

EX9251

Rear panel of the chassis

12 AWG (2.5 mm²), minimum 90° C wire, or one that complies with the local code—not provided

Panduit LCD10-10A-L or equivalent—not provided

Two 10-32 screws—provided

See Grounding Cable and Lug Specifications for EX9200 Switches.

EX9253

Right side of the chassis

14-10 AWG (2-5.3 mm²), minimum 90° C wire, or one that complies with the local code—not provided

Panduit LCD10-14B-L or equivalent—provided

Two M5 Pan Head screws—provided

  

Tools required for connecting an EX Series switch to earth ground:

  • An electrostatic discharge grounding strap (provided)

  • A Phillips (+) number 2 screwdriver to tighten the screws.

An AC–powered EX Series switch gains additional grounding when you plug the power supply in the switch into a grounded AC power outlet by using an AC power cord appropriate for your geographical location.

Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch

Table 2 lists the special instructions that you might need to follow before connecting earth ground to a switch.

Table 2: Special Instructions to Follow Before Connecting Earth Ground to an EX Series Switch

Switch

Special Instructions

EX3200 and EX4200

Some early variants of EX3200 and EX4200 switches for which the Juniper Networks model number on the label next to the protective earthing terminal is from 750-021xxx through 750-030xxx require 10-24x.25 in. screws.

EX4200, EX4500, and EX4550

If you plan to mount your switch on four posts of a rack or cabinet, mount your switch in the rack or cabinet before attaching the grounding lug to the switch.

Note:

The protective earthing terminal on switches mounted on four posts of a rack is accessible through the slot on the left rear bracket only if the rack is 27.5 in. (69.85 cm) through 30.5 in. (77.47 cm) deep for a switch mounted flush with the rack front and 29.5 in. (74.93 cm) through 32.5 in. (82.55 cm) deep for a switch mounted 2 in. (5.08 cm) recessed from the rack front. See Figure 1.
Figure 1: Connecting the Grounding Lug to a Switch Mounted on Four Posts of a Rack Connecting the Grounding Lug to a Switch Mounted on Four Posts of a Rack
  1
—

Protective earthing terminal

  3
—

Grounding lug

  2
—

Side mounting-rail

  4
—

Rear mounting-blade
Note:

The brackets must be attached to the chassis before the grounding lug is attached. (The brackets are shown pulled away from the chassis so that the protective earthing terminal is seen.)

Connecting Earth Ground to an EX Series Switch

To connect earth ground to an EX Series switch:

  1. Verify that a licensed electrician has attached the cable lug to the grounding cable.

  2. Connect one end of the grounding cable to a proper earth ground, such as the rack in which the switch is mounted.

  3. Attach an ESD grounding strap to your bare wrist, and connect the strap to the ESD grounding point on the switch.

  4. Place the grounding lug attached to the grounding cable over the protective earthing terminal. See Figure 2.

    Figure 2: Connecting a Grounding Cable to an EX Series Switch Connecting a Grounding Cable to an EX Series Switch

  5. Secure the grounding lug to the protective earthing terminal with the washers and screws.

  6. Dress the grounding cable and ensure that it does not touch or block access to other switch components and that it does not drape where people could trip over it.

See Also

Connecting AC Power to an EX4300 Switch

Before you begin connecting AC power to an EX4300 switch:

  • Ensure that you have taken the necessary precautions to prevent electrostatic discharge (ESD) damage (see Prevention of Electrostatic Discharge Damage).

  • Ensure that you have connected the device chassis to earth ground.

    CAUTION:

    Before you connect power to the switch, a licensed electrician must attach a cable lug to the grounding cable that you supply. A cable with an incorrectly attached lug can damage the switch (for example, by causing a short circuit).

    To meet safety and electromagnetic interference (EMI) requirements and to ensure proper operation, you must connect the EX4300 switch to earth ground before you connect it to power. For installations that require a separate grounding conductor to the chassis, use the protective earthing terminal on the switch chassis to connect to the earth ground. For instructions on connecting earth ground, see Connect Earth Ground to an EX Series Switch. An EX4300 switch gains additional grounding when you plug the power supply in the switch into a grounded AC power outlet by using the AC power cord appropriate for your geographical location (see AC Power Cord Specifications for an EX4300 Switch).

  • Install the power supply in the chassis. For instructions on installing a power supply in an EX4300 switch, see Installing an AC Power Supply in an EX4300 Switch.

EX4300 switches support 350 W, 715 W, or 1100 W AC power supplies depending on the switch model. After you install at least one power supply, you can connect power to the switch.

CAUTION:

Do not mix:

  • AC and DC power supplies in the same chassis

  • Power supplies with different airflow labels (AIR IN (AFI) and AIR OUT (AFO)) in the same chassis.

  • Fan modules with different airflow labels (AIR IN (AFI) and AIR OUT (AFO)) in the same chassis.

  • Power supplies and fan modules with different airflow labels (AIR IN (AFI) and AIR OUT (AFO)) in the same chassis.

Ensure that you have the following parts and tools available:

  • A power cord appropriate for your geographical location (provided)

Note:

Each power supply must be connected to a dedicated power source outlet.

To connect AC power to an EX4300 switch:

  1. Attach the grounding strap to your bare wrist and to a site ESD point.
    Note:

    The power supply slots are at the right end of the rear panel on 24-port and 48-port switches, and at the left end on 32-port switches.Figure 3 shows how to connect an AC power cord to an AC power supply installed on 24-port or 48-port EX4300 switches. The procedure is the same for 32-port EX4300 switches.

  2. Ensure that the power supplies are fully inserted in the chassis and the latches are secure. If only one power supply is installed, ensure that a cover panel is installed over the second power supply slot.
  3. Locate the power cord and power cord retainer shipped with the switch; the cords have plugs appropriate for your geographical location. See AC Power Cord Specifications for an EX4300 Switch.
  4. Push the end of the retainer strip into the hole next to the inlet on the power supply face plate until it snaps into place. Ensure that the loop in the retainer strip faces toward the power cord.
  5. Press the small tab on the retainer strip to loosen the loop. Slide the loop until you have enough space to insert the power cord coupler into the inlet.
  6. Insert the power cord coupler firmly into the inlet.
  7. Slide the loop toward the power supply until it is snug against the base of the coupler.
  8. Press the tab on the loop and draw out the loop into a tight circle (see Figure 3).
    Figure 3: Connecting an AC Power Cord to an AC Power Supply in an EX4300 SwitchConnecting an AC Power Cord to an AC Power Supply in an EX4300 Switch
  9. If the AC power source outlet has a power switch, set it to the OFF (O) position.
  10. Insert the power cord plug into an AC power source outlet.
  11. If the AC power source outlet has a power switch, set it to the ON (|) position.
  12. Verify that the IN OK and OUT OK LEDs on each power supply are lit green.

    If the OUT OK LED is lit amber, remove power from the power supply, and replace the power supply (see Removing an AC Power Supply from an EX4300 Switch). Do not remove the power supply until you have a replacement power supply ready: the power supplies or a cover panel must be installed in the switch to ensure proper airflow.

    CAUTION:

    We recommend that you install either a replacement power supply or a cover panel in the empty power supply slot to prevent chassis overheating and dust accumulation.

See Also

Connecting DC Power to an EX4300 Switch

Before you begin connecting DC power to an EX4300 switch:

  • Ensure that you have taken the necessary precautions to prevent electrostatic discharge (ESD) damage (see Prevention of Electrostatic Discharge Damage).

  • Ensure that you have connected the switch chassis to earth ground.

    CAUTION:

    Ensure that you install the power supply module first and then install the DC input wire, before closing input breaker ON.

    CAUTION:

    Before you connect power to the device, a licensed electrician must attach a cable lug to the grounding and power cables that you supply. A cable with an incorrectly attached lug can damage the device (for example, by causing a short circuit).

    To meet safety and electromagnetic interference (EMI) requirements and to ensure proper operation, you must connect the chassis to earth ground before you connect it to power. For installations that require a separate grounding conductor to the chassis, use the protective earthing terminal on the switch chassis to connect to the earth ground. For instructions on connecting earth ground, see Connect Earth Ground to an EX Series Switch.

  • Install the power supply in the chassis. For instructions on installing a DC power supply in an EX4300 switch, see Installing a DC Power Supply in an EX4300 Switch.

Ensure that you have the following parts and tools available:

  • DC power source cables (14–16 AWG) with ring lug (Molex 190700067 or equivalent) (not provided)

  • Phillips (+) screwdriver, number 2 (not provided)

  • Multimeter (not provided)

  • A 14-10 AWG STR (2.5-6 mm²), minimum 90°C wire grounding cable, or one permitted by the local code, with a Panduit LCD10-10A-L or equivalent grounding lug attached (not provided)

  • Two 10-32 x .25 in. screws with #10 split-lock washer (not provided)

  • Two #10 flat washers (not provided)

EX4300 switches can be configured with up to two DC power supplies. After you install at least one power supply, you can connect power to the switch.

CAUTION:

Do not mix:

  • AC and DC power supplies in the same chassis

  • Power supplies with different airflow labels (AIR IN (AFI) and AIR OUT (AFO)) in the same chassis.

  • Fan modules with different airflow labels (AIR IN (AFI) and AIR OUT (AFO)) in the same chassis.

  • Power supplies and fan modules with different airflow labels (AIR IN (AFI) and AIR OUT (AFO)) in the same chassis.

To connect DC power to an EX4300 switch:

  1. Attach the grounding strap to your bare wrist and to a site ESD point.
    Note:

    The power supply slots are at the right end of the rear panel on 24-port and 48-port switches, and at the left end on 32-port switches. Figure 5 shows how to secure ring lugs to the terminals on the DC power supply installed on 24-port or 48-port EX4300 switches. The procedure is the same for 32-port EX4300 switches.
  2. Verify that the DC power cables are correctly labeled before making connections to the power supply. In a typical power distribution scheme where the return is connected to chassis ground at the battery plant, you can use a multimeter to verify the resistance of the –48V and RTN DC cables to chassis ground:

    • The cable with very low resistance (indicating a closed circuit) to chassis ground is positive (+) and will be installed on the V+ (return) DC power input terminal.

    • The cable with very high resistance (indicating an open circuit) to chassis ground is negative (–) and will be installed on the V– (input) DC power input terminal.

    CAUTION:

    You must ensure that power connections maintain the proper polarity. The power source cables might be labeled (+) and (–) to indicate their polarity. There is no standard color coding for DC power cables. The color coding used by the external DC power source at your site determines the color coding for the leads on the power cables that attach to the DC power input terminals on each power supply.
  3. Install heat-shrink tubing insulation around the power cables.

    To install heat-shrink tubing:

    1. Slide the tubing over the portion of the cable where it is attached to the lug barrel. Ensure that tubing covers the end of the wire and the barrel of the lug attached to it.

    2. Shrink the tubing with a heat gun. Ensure that you heat all sides of the tubing evenly so that it shrinks around the cable tightly.

    Figure 4 shows the steps to install heat-shrink tubing.

    Note:

    Do not overheat the tubing.
    Figure 4: How to Install Heat-Shrink Tubing How to Install Heat-Shrink Tubing
  4. Ensure that the input circuit breaker is open so that the voltage across the DC power source cable leads is 0 V and that the cable leads will not become active while you are connecting DC power.
    Note:

    The V+ terminals are referred to as +RTN and V– terminals are referred to as –48 V in DC Power Wiring Sequence Warning and DC Power Electrical Safety Guidelines.
  5. Ensure that the power supplies are fully inserted in the chassis.
  6. Remove the terminal block cover. The terminal block cover is a piece of clear plastic that snaps into place over the terminal block.
  7. Remove the screws on the terminals by using the screwdriver. Save the screws.
    Warning:

    Ensure that the power cables do not block access to switch components or drape where people can trip on them.
    Note:

    The DC power supply has five terminals, two positive terminals labeled V+ and two negative terminals labeled V–, for connecting the power supply to a dedicated DC power source by using the DC power source cables labeled positive (+) and negative (–), and one terminal for connecting the power supply to earth ground (see Figure 5). The V+ terminals are shunted internally together, as are the V– terminals to provide parallel current path.
  8. Connect one end of the grounding cable to a proper earth ground, such as the rack in which the switch is mounted.
  9. Place the grounding lug attached to the grounding cable over the earth ground terminal. The protective earth ground terminal on an EX4300 switch, mounted on four posts of a rack, is accessible through the slot on the mounting bracket on the left side only. If you are unable to access protective earthing terminal, you can connect the grounding cable to the earth ground terminal on the DC power supply.
  10. Secure the grounding lug to the protective earthing terminal with the washers and screws.
  11. Dress the grounding cable and ensure that it does not touch or block access to other switch components.
    Warning:

    Ensure that the cable does not drape where people could trip over it.
  12. Connect each power supply to the power source. Secure power source cables to the power supplies by screwing the ring lugs attached to the cables to the appropriate terminals by using the screw from the terminals (see Figure 5).

    • To connect a power supply to a power source:

      1. Secure the ring lug of the positive (+) DC power source cable to one of the + terminals on the DC power supply.

      2. Secure the ring lug of the negative (–) DC power source cable to the – terminal adjacent to the + terminal that you connected to on the DC power supply.

      3. Connect the ground wire to earth ground if the switch is not in a grounded rack. The protective earth ground terminal on an EX4300 switch, mounted on four posts of a rack, is accessible through the slot on the mounting bracket on the left side only. If you are unable to access protective earthing terminal, you can connect the grounding cable to the earth ground terminal on the DC power supply.

      4. Tighten the screws on the power supply terminals until they are snug by using the screwdriver. Do not overtighten—apply between 5 lb-in (0.56 Nm) and 6 lb-in (0.68 Nm) of torque to the screws.

      If you have a second installed power supply, connect it in the same way you did the first.

    • To connect one power supply to two power sources:

      1. Secure the ring lug of the positive (+) DC power source cable from the first DC power source to a + terminal on the power supply.

      2. Secure the ring lug of the negative (–) DC power source cable from the first DC power source to the – terminal adjacent to the + terminal on the DC power supply to which you connected the ring lug of the positive (+) DC power source cable from the first DC power source.

      3. Secure the ring lug of the positive (+) DC power source cable from the second DC power source to the other + terminal on the power supply.

      4. Secure the ring lug of the negative (–) DC power source cable from the second DC power source to the – terminal adjacent to the + terminal on the DC power supply to which you connected the ring lug of the positive (+) DC power source cable from the second DC power source.

      5. Connect the ground wire to earth ground if the switch is not in a grounded rack. The protective earth ground terminal on an EX4300 switch, mounted on four posts of a rack, is accessible through the slot on the mounting bracket on the left side only. If you are unable to access protective earthing terminal, you can connect the grounding cable to the earth ground terminal on the DC power supply.

      6. Tighten the screws on the power supply terminals on both the power supplies until snug using the screwdriver. Do not overtighten—apply between 8 lb-in. (0.9 Nm) and 9 lb-in. (1.02 Nm) of torque to the screws.

      If you have a second installed power supply, connect it in the same way you did the first.

    Figure 5: Securing Ring Lugs to the Terminals on the DC Power Supply Securing Ring Lugs to the Terminals on the DC Power Supply
  13. Replace the terminal block cover.
  14. Close the input circuit breaker.
  15. Verify that the IN OK and OUT OK LEDs on the power supply are lit green and are on steadily.

See Also