Install DC Power Cables and Apply Power to the Modular System (DC)

This topic describes how to build the DC power cables and apply power to the DC model.

The DC model applies standby power to the installed components when two or more of the power supplies have input power connected. If the CMM is installed and functioning, main power will be controlled by the CMM settings. If the CMM is not installed or is not functioning, main power will be automatically activated after a 3 minute delay.

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Caution - The DC power source must be located in the same premises as the DC model of the modular system. The power source cannot be in one building with the modular system in another building. This restriction minimizes the possibility of transient energy appearing on the main DC input to the modular system.

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Caution - A power disconnect device is not incorporated with the equipment. You must incorporate an external, readily accessible disconnect device to the equipment.

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Caution - This product does not provide branch circuit overcurrent protection as defined by the US NEC (United States National Electrical Code), Article 100. Installations of this product in compliance with the US NEC must be on branch circuits with overcurrent protection as defined by Article 480.3 of the US NEC. Product power inputs with current ratings 16A or less must have a branch circuit or supplementary overcurrent protection device rated at no more than 20A. Product power inputs with current ratings of more than 16A must have a branch circuit or supplementary overcurrent protection device rated at no more than 160% of the product input current rating. Other national and/or local electrical codes might apply to the installation of this product.

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1. Ensure that the circuit breakers on your power source are open or that the fuses are removed.

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   Caution - To prevent electrical shock, ensure that no power is present on the circuits to which you are connecting.

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2. Review the DC power cable wiring diagram.

   See DC Power Cable Wiring Reference.

3. Disengage all four power supplies from the chassis.

   Do not remove the supplies completely. Pull them forward by approximately 1 inch (25 mm).

   See Remove the Power Supplies (DC).

4. Assemble the ground and power cable ends using the following specifications and the following steps:
   

   Number of circuits 8 Number of power cables 8 (2 wires in each cable) Number of ground cables 1 Input voltage per circuit -48 VDC or -60 VDC nominal Maximum amperage per circuit 60A Wire gage 6 AWG

   1. Crimp a ground lug onto a ground cable.

      Use a crimping tool or approved equivalent to secure the lugs onto the cables.

   2. Use an M6 nut and washer to fit the lug to the 6 mm electrical grounding stud on the rear of the system chassis.

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      Note - This 6 mm electrical grounding stud is a safety earth bonding point.

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      No. Description 1. Chassis DC grounding stud

   3. Connect the other end of the ground cable to a stable ground point.

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      Caution - The Netra 6000 DC system enclosure must be reliably connected to earth ground. The Netra 6000 DC system enclosure has a safety earth bonding point. This bonding point can be used to meet the central office requirements for enclosure or shelf grounding in GR1089-CORE. The grounding point is for connection of an electrical conductor between the system enclosure metal and a nearby point on the central office ground system. The use of this bonding point connection is optional if the system chassis mounting meets the requirements for a reliable chassis ground connection.

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   4. Crimp single-hole, right-angle lugs onto the input and return cables.
   5. Remove the safety cover from the DC power unit input area at the back of the chassis.

      Use a screwdriver to loosen the green captive screws.

      
      
   6. Use M6 nuts and washers to secure the lugs to the DC input unit terminals.

      See DC Power Cable Wiring Reference.

   7. Replace the safety cover on the rear of the DC input unit.

      Use a screwdriver to tighten the green captive screws.

      
      
5. Ensure that the circuit breakers on your power source are open or that the fuses are removed.

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   Caution - To prevent electrical shock, ensure that no power is present on the circuits to which you are connecting.

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6. Connect the remaining power cables to the customer-supplied circuit breakers or fuse panel.
7. Verify all DC connections before applying power.
8. Apply power to the chassis by closing the circuit breakers or installing the fuses.
9. Reengage the four power supplies into the chassis.

   See Install the Power Supplies (DC).

   Main power is automatically distributed to the modular system.

10. Verify the chassis initialization by viewing the front or rear status LEDs.

    • Green OK LEDs – Illuminate a solid green light, indicating successful initialization.

    • Amber fault LED – Illuminates if a fault is detected. If the amber fault LED is illuminated, check for other fault indicators on modular components, unplug the chassis, and take corrective actions.

    
    

Related Information

• Install DC Power Cables and Apply Power to the Modular System (DC)

• Determining DC Power Requirements