Health and Safety Forum

Knowledge Network | Health and Safety Forum

Reply To: Tree workers working near de-energised HV lines

  • Stephen Albrecht

    Member
    3 August 2022 at 3:06 pm

    Hi Brett,

    MainPower’s Network Operations and Control Centre has advised:

    It all hinges on how “near” to the HV lines they are.

    The main situations are as follows:

    Work inside the ‘close worker zone’:

  • Lines must be isolated.
    Access permit held by a competent person (could be staff or contractors);
    the cost of this is charged to the third-party vegetation contractor, if
    they are not competent to hold access (currently we have none who are
    competent to that level).
  • Work outside the ‘close worker zone’:

  • Work can be completed
    under a Close Approach Consent, the specified safety distance must also be
    outside the close worker zone (and therefore well outside the MAD).
  • In some cases, we may
    choose to “de-engergise for safety” in case we see increased risk of trees
    falling clear of the workers and into lines. Third party vegetation
    workers must operate under a Close Approach Consent remain outside the
    specified safety distance, which must also be outside the close worker
    zone (and therefore well outside the MAD). This is different from an HV
    isolation. Power is off for safety, but no permit is applied and
    third-party workers must treat lines as live at all times.The question is unclear, as it all hinges on how “near” to the HV lines they are.

    The main situations are as follows:

    Work inside the ‘close worker zone’:
    – Lines must be isolated. Access permit held by a competent person (could be staff or contractors); the cost of this is charged to the third-party vegetation contractor, if they are not competent to hold access (currently we have none who are competent to that level).

    Work outside the ‘close worker zone’:
    – Work can be completed under a Close Approach Consent, the specified safety distance must also be outside the close worker zone (and therefore well outside the MAD).
    – In some cases, we may choose to “de-engergise for safety” in case we see increased risk of trees falling clear of the workers and into lines. Third party vegetation workers must operate under a Close Approach Consent remain outside the specified safety distance, which must also be outside the close worker zone (and therefore well outside the MAD). This is different from an HV isolation. Power is off for safety, but no permit is applied and third-party workers must treat lines as live at all times.

  • Regards

    Stephen