Procedure for Permit to Work or Line Clear
A line clear or a permit to work (PTW) on any electrical equipment or line is issued by an authorised person to another authorised person. If there are more than one gangs working under the same supervisor, each gang takes sub-line clears from the supervisor who has taken the line clear. In case, the line clear has to be issued for the supervisor, s/he takes self line clear. In this case also, all the precautions that are to be given in issue and return of line clear are followed.
Line clear books are very important records. Pages in these books are serially numbered and no paper from this book is used for any other purpose. If any page is to be destroyed then the custodian specifically mentions the reasons for doing so. It is attested by his/her dated signature. The line clear books are reviewed periodically by the Competent Authority.
Line clear can be issued/received over telephone. It is desirable that the issuer/receiver recognise each other's voice. The requisition for line clear and the line clear issue messages are repeated by both the parties to ensure that line clears are issued/received on the equipment on which it is intended. A secret code number is followed in such cases.