ENA NENS 04-2006 National guidelines for safe approach distances to electrical and mechanical apparatus These Guidelines are intended to— (a) Support the Electricity Supply Industry in ensuring the safety of electrical and other workers and the general public by the development of appropriate Safe App
| Document Contents |
| ENA NENS 04-2006 NATIONAL GUIDELINES FOR SAFE APPROACH DISTANCES TO ELECTRICAL AND MECHAN... |
| CONTENTS |
| 1 PREFACE |
| 2 OBJECTIVES |
| 3 SCOPE |
| 4 DEFINITIONS |
| 5 METHODOLOGY |
| 5.1 General |
| 5.2 Authorised Persons, Instructed Persons and Ordinary Persons |
| 5.3 Power frequency |
| 5.4 Switching surge |
| 5.5 Risks excluded |
| 6 SAFE APPROACH DISTANCES |
| 6.1 Safe Approach Distance for Ordinary Persons |
| 6.2 Safe Approach Distances for Instructed or Authorised Persons |
| 6.3 Safe Approach Distance-Special Limit of Approach for Authorised Persons Only |
| 6.4 Safe Approach Distances for Mobile Plant Operated by Ordinary Persons |
| 6.5 Safe Approach Distances for Mobile Plant Operated by Instructed or Authorised Persons |
| 6.6 Safe Approach Distances for Vehicles Operated by Ordinary Persons |
| 6.7 Safe Approach Distances for Vehicles Operated by Instructed or Authorised Persons |
| 6.8 Scaffolding |
| 7 FACTORS TO CONSIDER IN VARYING SAFE APPROACH DISTANCES |
| 7.1 Increases to Safe Approach Distances |
| 7.2 Decreases to Safe Approach Distances-Determination of Special Limits for Authorised P... |
| 7.2.2 Risk Assessments for Developing Safe Approach Distances-Special Limit for Authorise... |
| 7.2.3 Safety Observers |
| 7.2.4 Mobile plant |
| 7.3 Variation of calculated electrical withstand distance |
| 7.3.1 Maximum overvoltage |
| 7.3.2 Weather conditions |
| ANNEX A - BASE ASSUMPTIONS FOR FLASHOVER DERIVATIONS |
| A1 GENERAL |
| A2 DERIVATION OF POWER FREQUENCY FLASHOVER |
| A3 DERIVATION OF SWITCHING SURGE WITHSTAND DISTANCE |
| A4 DERIVATION OF D.C. AIR GAP DISTANCES |
| ANNEX B - DERIVATION OF SAFE APPROACH DISTANCES FOR INSTRUCTED OR AUTHORISED PERSONS |
| B1 PERSONAL APPROACH |
| B2 MOBILE PLANT |
| ANNEX C - SAMPLE SAFE APPROACH DISTANCE CALCULATIONS |
| ANNEX D - TYPES OF PERSONS AND TYPICAL ATTRIBUTES FOR PERSONS TO WORK ON OR NEAR ELECTRIC... |
| ANNEX E - REFERENCED DOCUMENTS |
These Guidelines are intended to—
(a) Support the Electricity Supply Industry in ensuring the safety of electrical and other
workers and the general public by the development of appropriate Safe Approach
Distances to electrical apparatus for various classes of persons, and mobile plant and
equipment.
(b) Provide the basic technical material necessary for Network Operators to develop
work practice, and related training and awareness programs.
(c) Provide recommendations for appropriate Safe Approach Distances for members of
the general public.
(d) Provide the Electricity Supply Industry with a sound basis for controlling activities,
where possible, of the general public near network assets.
These Guidelines apply to all work on or near electrical apparatus managed by Network Operators, but excluding:
high voltage live work;
work on electrical apparatus which is isolated and earthed and covered by a Network Operator’s Access Authority;
work on electrical installations complying with AS/NZS 3000; and
extra low voltage work.
These Guidelines should be applied in the context that-
(i)Appropriate workplace hazard and risk assessments are carried out as required.
(ii)The Safe Approach Distances used are appropriate for the type of person, training and work to be performed.
(iii)Other Guidelines applicable to particular work processes such as vegetation management are to be used.
