UK Power Networks HSS 40 059b

The use of Megger Cable identifying Generator CI TX for the identification of the Neutral Conductor (All cores dead)

Refer to HSS 40 059 for further information on the procedure.

1.1 Identifying neutral conductor where no cores are live: How to identify the neutral conductor on a multi-cored cable that has lost all live phases:

1. Identify cable in line with DSR 01 018 identification of LV cables; 2. Prepare cable ready for testing at the location in which the neutral is to be identified; 3. Confirm status of cable by completing full test using approved test lamps to confirm all cores are dead; 4. Select an appropriate test point in which the signal can be injected from. This can be a customer’s cut-out, street furniture or LV equipment where the Neutral can be clearly identified; 5. Connect the CI TX Signal injection box to the appropriate test point, it Is important to note that the red lead needs to be connected to the phase core and that the black lead is connected to the neutral conductor. (This is very important for the test to work correctly);

Figure 1 - Connection of Signal Generator

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6. At the remote end of the circuit where the neutral is being identified a short needs to be applied between the dead core and the Neutral core that the signal is being injected on

Figure 2 - Remote end circuit

When the correct core is selected the signal box will indicate this with a Green LED otherwise it will indicate a red LED indicating a problem, Rotate through the cores until the circuit is confirmed as ok;

Figure 3 - Signal Generator circuit confirmation

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7. At the remote end using the receiving device identify the Neutral conductor as follows: Confirm the receiving device arrow is pointing in the direction of the signal Generator

Figure 4 - Confirm arrow in correct direction

The receiving unit showing a red signal will identify the Phase core

Figure 5 - Phase core identification The receiving unit showing a green signal will identify the Neutral Core

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Figure 6 - Neutral core identification

8. Once the Neutral core has been identified clearly, mark up the Neutral core with identification tape; 9. Carry out jointing activities as per job requirements; 10. Once circuit has been energised carry out testing in accordance with DSR 01 016 Process on how to ensure customers have correct polarity and phase rotation.

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Figure 1 - Connection of Signal Generator...... 1 Figure 2 - Remote end circuit...... 2 Figure 3 - Signal Generator circuit confirmation...... 2 Figure 4 - Confirm arrow in correct direction...... 3 Figure 5 - Phase core identification...... 3 Figure 6 - Neutral core identification...... 4

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