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Connect the SRX4120 to Power

This section takes you through the steps and safety precautions to be foolowing while connnecting power to the SRX4120, to prevent equipment damage and personal injury.

Ground the SRX4120

Note:

To meet safety and electromagnetic interference (EMI) requirements and to ensure proper operation, you must connect the SRX4120 to an earth ground before you connect it to power.

Before you connect an earth ground to the protective earthing terminal of the device, ensure that a licensed electrician attaches an appropriate grounding terminal to the grounding cable you supply. Using a grounding cable with an incorrectly -attached terminal can damage the device.

Before connecting the device to an earth ground, ensure that you have the following parts and tools:

  • An electrostatic discharge (ESD) grounding strap.

  • A grounding cable for your device—The grounding cable must be 6 AWG (4.11 mm²) stranded wire and rated 90 °C or per local electrical code.

  • A grounding 2-hole terminal for your grounding cable—This attaches to the chassis grounding point. The Panduit LCD6-14A-L terminal lugs, or equivalent are sized for 6 AWG (4.11 mm²) power source cables.

  • Two pan head M5 x10 mm screws with integrated split washers (not provided)—The screws and washers are used to secure the grounding lug to the protective earthing terminal.

  • A Phillips screwdriver to tighten the screw.

You must install heat-shrink tubing insulation around the crimped section of the power cables and lugs.

To ground the SRX4120, connect a grounding cable to earth ground. Attach the grounding cable to the chassis grounding point. Under all circumstances, use this grounding connection to ground the chassis.

To ground the device:

  1. Wrap and fasten one end of the electrostatic discharge (ESD) grounding strap to your bare wrist and connect the other end of the strap to the ESD point on the chassis.
    Figure 1: Chassis ESD point Chassis ESD point
  2. Ensure that all grounding surfaces are clean and brought to a bright finish before making the grounding connections.
  3. Connect the grounding cable to a proper earth ground, such as the rack in which you mount the device.
  4. Locate the chassis grounding point.
    Figure 2: Grounding Point on the SRX4120 Rear view of server chassis showing cooling fans with AIR OUT labels for airflow direction and highlighted grounding points.
  5. Secure the grounding cable terminal to the grounding point using M5 screws (not provided).
    Figure 3: Connect the Grounding Cable to the SRX4120 Connect the Grounding Cable to the SRX4120
  6. Place the grounding cable terminal attached to the grounding cable over the grounding point.
  7. Verify that the grounding cable does not touch or block access to the device components. Make sure that it does not trail across the floor where people could trip over it.
    Note:

    Ensure that the device is permanently connected to ground during operation.

Install Heat-Shrink Tubing on a Power Cable

To install heat-shrink tubing insulation around the power cables:
  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.
    CAUTION:

    Do not overheat the tubing.
    Figure 4: Install Heat-Shrink Tubing Install Heat-Shrink Tubing

Connect AC Power to the SRX4120

Before you begin:

  • Ensure that you have grounded the SRX4120.

  • Ensure that you have read the guidelines and precautions in the Juniper Networks Safety Guide.

  • Ensure that you have a power cord appropriate for your geographical location available to connect AC power to the device.

  • Ensure that you fully insert the PSUs into the chassis.

Connect the JPSU-450W-AC to Power

To connect the JPSU-450W-AC to AC power:

  1. Wrap and fasten one end of the ESD wrist strap around your bare wrist, and connect the other end of the strap to the ESD point on the device.
  2. Locate the AC power cords shipped with the SRX4120; the cords have plugs appropriate for your geographical location.
  3. Insert the coupler end of the power cord into the AC power cord inlet on the AC power supply faceplate.
  4. Push the power cord retainer onto the power cord.
    Figure 5: Connect AC Power Cord Connect AC Power Cord
  5. Repeat step 4 and step 5 to insert the second power cord.
  6. If the AC power source outlet has a power switch, set it to the off (O) position.
  7. Insert the power cord plug into an AC power source outlet.
    Note:

    Connect each power supply to a dedicated AC power feed and a dedicated external circuit breaker. We recommend that you use a 10 A (250 VAC) minimum, or as permitted by the local code.
  8. If the AC power source outlet has a power switch, set it to the on (|) position.

Connect DC Power to the SRX4120

Before you begin:

Warning:

Before performing the following procedure, ensure that you remove the power from the DC circuit. To ensure that all power is off, locate the circuit breaker on the panel board that services the DC circuit. Switch the circuit breaker to the OFF position (0), and tape the switch handle of the circuit breaker in the OFF position.

Connect the JPSU-650W-DC-AFO to Power

The DC power cables for the JPSU-650W-DC-AFO are rated 16 AWG.

To connect the JPSU-650W-DC-AFO to power:

  1. Switch off the dedicated facility circuit breakers. Ensure that the voltage across the DC power source cable leads is 0 V. You must ensure that the cable leads do not become active during installation.
  2. Wrap and fasten one end of the ESD wrist strap around your bare wrist, and connect the other end of the strap to the ESD point on the device.
  3. Remove the clear plastic cover that protects the terminal studs on the faceplate.
    Figure 6: Remove the Terminal Cover Power supply unit with terminals labeled V- and V+ for voltage connections, green arrow indicates connector direction.
  4. Verify that you have correctly labeled the DC power cables 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 ohm output of the –48 V and return (RTN) DC cables to chassis ground. The cable with very large resistance (indicating an open circuit) to chassis ground will be –48V. The cable with very low resistance (indicating a closed circuit) to chassis ground will be RTN.

    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 terminal studs on each power supply.
  5. Remove the screws from the terminals, using a Phillips (+) screwdriver, number 2.
    Figure 7: Remove the Screws Technical illustration of a power supply unit showing connector with labeled V+ and V- connections and green arrow indicating insertion direction.
  6. Secure each power cable ring terminal to the terminals with the screws.

    • Secure each positive (+) DC source power cable lug to an RTN (return) terminal.

    • Secure each negative (–) DC source power cable lug to a –48 V (input) terminal.

    Figure 8: Connect the DC Power CablesTechnical illustration of a power supply unit panel with connectors labeled V- and V+, cables, and screws, indicating installation step.
    Note:

    Connect each power cable to a dedicated external circuit breaker. We recommend that you use a 10 A (80 VDC), or as permitted by the local code.
  7. Replace the clear plastic cover over the terminal studs on the faceplate.
  8. Verify that the power cables are connected correctly. The cables must not touch or block access to device components, and they must not cause a tripping hazard.
  9. Switch the circuit breaker on the panel board that services the DC circuit to the ON (|) position.
  10. Connect the power cables to the external DC power source. If the external DC power source has a switch, set it to the ON (|) position.

Power Off the SRX4120

You can power off the SRX4120 in any of the following ways:

  • Graceful shutdown:

    • Using hardware—Press and immediately release the Power button.

    • Using the CLI—Use the request system power-off command.

    The device begins gracefully shutting down the operating system (OS) and then powers itself off.

    CAUTION:

    Use the graceful shutdown method to power off or reboot the firewall.

  • Forced shutdown—Press the Power button and hold it for ten seconds. The device immediately powers itself off without shutting down the OS.

    CAUTION:

    Use the forced shutdown method as a last resort to recover the firewall if the firewall OS is not responding to the graceful shutdown method.

To remove power completely from the device, unplug the AC power cord or DC power supply cable.

After powering off a PSU, wait at least 60 seconds before turning it back on. After powering on a PSU, wait at least 10 seconds before turning it off.

When the system is completely powered off and you turn on the power supply, the device starts as the PSU completes its startup sequence. If the device finishes starting and you need to power off the system again, first issue the request vmhost halt command.

Note:

The fans in the PSU continue to rotate even after you power off the SRX4120. To stop the fans, remove the power cord from the PSU. The fans will stop in a few seconds.

After turning on the PSU, it can take up to 60 seconds for status indicators—such as the PWR LED and the show chassis command display—to indicate that the PSU is functioning normally. Ignore error indicators that appear during the first 60 seconds.