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Connecting DC Power to an EX2200 Switch

The power supply is built in along the rear panel.

Warning: DC-powered switches are intended for installation only in a restricted access location.

Before you begin connecting DC power to the switch, ensure that you have connected the switch chassis to earth ground.

Caution: Before you connect power to the switch, 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 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 switch to earth ground before you connect them 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 Connecting Earth Ground to an EX Series Switch.

Note: Grounding is required for DC systems and recommended for AC systems. An AC-powered switch gets 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.

Ensure that you have the following parts and tools available:

  • DC power source cables (14 AWG) with ring lug (Molex 0190700067 or equivalent) (not provided) attached to them by a licensed electrician
  • Phillips (+) screwdriver, number 2

To connect DC power to the switch:

  1. Ensure that the input circuit breaker is open so that the cable leads will not become active while you are connecting DC power.

    Note: The DC power supply in the switch has four terminals labeled A+, B+, A–, and B– for connecting DC power source cables labeled positive (+) and negative (–). The terminals are covered by a clear plastic cover.

    Note: The A+ and B+ terminals are referred to as +RTN and A– and B– terminals are referred to as –48 V in DC Power Wiring Sequence Warning and DC Power Electrical Safety Guidelines.

  2. Grasp the plastic cover in the middle, gently flex it outwards, and pull it out. Save the cover.
  3. Remove the screws on the terminals 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.

  4. Connect the power supply to the power sources. Secure power source cables to the power supply by screwing the ring lugs attached to the cables to the appropriate terminals by using the screw from the terminals (see Figure 49).

    Figure 49: Securing Ring Lugs to the Terminals on the DC Power Supply

    Securing Ring Lugs to the Terminals on the DC Power Supply
    • To connect the power supply to a power source:
      1. Secure the ring lug of the positive (+) DC power source cable to the A+ or B+ terminal on the DC power supply.
      2. Secure the ring lug of the negative (–) DC power source cable to the A– or B– terminal on the DC power supply.
      3. Tighten the screws on the power supply terminals until snug using the screwdriver. Do not overtighten—apply between 8 in.-lb (0.9 Nm) and 9 in.-lb (1.02 Nm) of torque to the screws.
    • To connect the 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 the 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 A– terminal on the power supply.
      3. Secure the ring lug of the positive (+) DC power source cable from the second DC power source to the B+ 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 B– terminal on the power supply.
      5. Tighten the screws on the power supply terminals on both the power supplies until snug using the screwdriver. Do not overtighten—apply between 8 in.-lb (0.9 Nm) and 9  in.-lb (1.02 Nm) of torque to the screws.
  5. Hook the plastic cover on one side of the terminal block and gently flex it inwards to hook it on the other side also.
  6. Close the input circuit breaker.

Related Documentation

Modified: 2015-06-23