When cables are cut in a submarine cable system, the power supply is switched on branching units (BUs) to ensure the power supply for the underwater devices that function properly. Hence, services on these devices will not be interrupted. In addition, BUs can ground faulty cables for maintenance.
Prerequisites
- A BU has been created.
- At least one port of the BU is bound to the submarine line monitor (SLM) NE.
- Lines are bound to the BU.
- Check the test status of the bound lines and make sure all the test are stopped.
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Context
NOTICE: Switching the power supply on a BU is potentially service-affecting. During the switching, verify that the power feeding equipment (PFEs) are properly connected to the three ports of the BU. If you proceed with the switching without verification, the switching will fail or even burn components.
Procedure
- In the NE Explorer, select an NE and choose from the Function Tree.
- Optional: In the window that is displayed, right-click a row of BU information and choose from the shortcut menu.
- Select a row of BU information and click Switch Power Supply. Confirm all the line tests are stopped on all lines bound to the BU in the message box and then set the parameters in the dialog
box that is displayed.
NOTE: - Current Status indicates the current BU status; Object Status is determined by the BU Status Control value.
- If Switching Condition is not Forced Switching, the power supply can be switched only when the terminal voltage is lower than 500 V on the BU.
- Click OK.
- If three ports of a BU are connected to PFEs or two ports of the BU are connected to PFEs and the third port is grounded, a progress bar will be displayed.
- If the three ports of a BU are not connected to PFEs as required, a message is displayed indicating that the operation is service-affecting. In this case, click OK if you want to continue the power supply switching. Click Cancel if you want to return to the Switch Power Supply dialog box and repeat 3.
NOTE: The power supply switching interval must be more than 30s.
- In the dialog box for verifying the port grounding status on the BU, check PFEs bound to the ports, ensure that the three ports are grounded, and then click OK.
- In the dialog box for verifying the polarity of power supply devices, ensure that the PFE works properly and then click OK. A progress bar is displayed.
- In the dialog box for verifying a successful power supply switching, adjust the PFE, ensure that the power supply is switched on the BU, and then click OK. NOTE:
- In constant current mode, adjust the voltage on the source PFE. If the voltage on the sink PFEs changes accordingly, the power supply is switched successfully; otherwise, the power supply switching fails.
- In constant voltage mode, adjust the current on the source PFE. If the current on the sink PFEs changes accordingly, the power supply is switched successfully; otherwise, the power supply switching fails.