Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


Connecting DC Power to the Junos Space Appliance

Before connecting the Junos Space Appliance to a DC power source, do the following:

  • Ensure that you have read the guidelines in the DC Power Electrical Safety Guidelines topic.

  • Ensure that you have taken the necessary precautions to prevent ESD damage.

  • Ensure that you have grounded the appliance by connecting the DC power supply grounding cable to earth ground.


    Before you connect power to the Junos Space Appliance, in order to meet the safety requirements and ensure proper operation, get a licensed electrician to attach a cable lug to the grounding and power cables that you supply. A cable with an incorrectly attached lug can damage the appliance (for example, by causing a short circuit).

  • Ensure that you have the following parts and tools available:

    • (Optional) Electrostatic discharge (ESD) grounding strap

    • DC power source cables (12-14 AWG) with ends of the wire stripped ~12mm and twisted

    • Phillips (+) screwdriver, number 1

You connect DC source power to the appliance by attaching power cables from external DC power sources to the terminal studs on the DC power supply module faceplates.


DC-powered Junos Space Appliances are intended for installation only in restricted access locations.


Before you perform the following procedure, ensure that power is removed 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, and tape the switch handle of the circuit breaker in the OFF position.

To connect the DC source power to the Junos Space Appliance, do the following:

  1. (Optional) Attach an electrostatic discharge (ESD) grounding strap to your bare wrist and connect the strap to an external ESD point.
  2. Ensure that the power supply module is fully inserted in the chassis.
  3. 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 when you connect the DC power.
  4. Remove the clear plastic cover protecting the terminal on the faceplate.
  5. Remove the screws on the terminals by using the screwdriver. Save the screws.
  6. Connect the stripped and twisted wires to wire clamps under the DC terminal screws as shown in Figure 1.
    Figure 1: Connecting a DC Power Supply ModuleConnecting a DC Power Supply Module
  7. Use the terminal screws to secure the power source cables to the power feed on the appliance by attaching the twisted wires that are attached to the cables to the appropriate terminals.
  8. Remove the screw on the grounding terminal by using the screwdriver. Save the screw.

    The grounding terminal is located to the right and above the terminals, as shown in Figure 2.

    Figure 2: DC Power Supply GroundingDC Power Supply Grounding
  9. Connect the grounding lug to the earthing terminal using the screw, as shown in Figure 2.
  10. Attach the plastic safety cover.
  11. Close the input circuit breaker.

The Junos Space Appliance starts powering on when you supply power to the power supply module. If the power supply module is correctly installed and functioning normally, the LED on the power supply module displays green when the power supply module is powering the appliance, and amber when the power supply module is in standby mode (not powering the appliance).