Lesson 3 – General Lock-out Procedure

ELECTRICAL  INSTALLATIONS

• Only a competent electrician can work on high tension equipment
• Where possible the lock out should be carried out on the power circuit not on the control circuit
• Where the installation is sequence interlocked, the other equipment must also be isolated where the  possibility exists  that  such  equipment  may  cause  injury to persons (Ring feeds).
• Make an entry  in  the  isolation record  book  or  substation record  book  if  in  a substation indicating the type of installations that you intend working on and the reason for the lock-out, your name and signature, date and time of the lock-out Where “Ring feeds” or “Sequence interlocking” are concerned, where the equipment could be supplied from two different areas or substations, entries to be made in both isolation/substation records books.
• Isolate or de-energise the power source.
• Lock the power source with a padlock and keep key with you.
• Display a ‘Do not start’ warning sign on the power source.
• Ensure the effectiveness of the lock out by attempting to start the equipment before work commences.
• When work is finished check if everything is in order, remove warning sign and padlock then clear the record book by signing and indicating the finishing time.
• If the person  who  installed the  lock  is  not  available  for  any  other reasons  a responsible competent qualified person only after he has satisfied himself that it is safe to do so may remove the lock or the responsible Head of department, may give permission in writing to a competent person to remove the lock under the following conditions:

–He/she has satisfied himself that it is generally safe to remove the lock. He/she make an entry in the isolation record book stating the reason for his action, the name of the person to whom the permission is given and the time.

• In high tension  equipment, only the responsible Head of  department may give permission in writing or in the isolation/substation record book to a competent qualified person assisted by a second competent person to remove the lock.

MECHANICAL PUMPS AND FANS

• Where practically possible or in main pump stations make an entry in the isolation record book/pump log book indicating the name of the pump or fan that you intend working on and the reason for the lock-out, location, your name and signature, date and time of the lock-out.
• Where not practically possible an entry using a clear note is to be displayed on the pump or fan starter isolating point, indicating your name, date, time and reason for lock-out, such note(s) shall be kept in a file to be kept in the GEF’s office for future reference.
• Isolate or de-energise the power source and lock with a padlock.
• Display a ‘Do not start’ warning sign on the power source.
• Ensure the effectiveness of the lock out by attempting to start the equipment before work commences.
• On completion check if everything is in order, remove warning sign and padlock then clear the record book by signing and indicating the finishing time.
• If the person  who  installed the  lock  is  not  available  for  any  other  reasons a responsible competent qualified person only after he has satisfied himself that it is safe to do so may remove the lock or the responsible Head of department, may give permission in writing to a competent person to remove the lock under the following conditions:
• He/she has satisfied himself that it is generally safe to remove the lock. He/she make an entry in the isolation record book stating the reason for his action, the name of the person to whom the permission is given and the time.

PNEUMATIC EQUIPMENT

• Where practically possible make an entry in the isolation record book/compressor log book indicating the type of pneumatic equipment you intend working on and the reason for the lock-out, location, your name and signature, date and time of the lock­ out.
• Where not practically possible an entry using a clear note is to be displayed at the equipment or valve (isolating point) indicating your name, date, time and reason for lock-out, such note(s) shall be kept in a file to be kept in the GEF’s office for future reference.
• Secure the control valve and/or actuator with a chain in the manner that no mechanical movement is allowed.
• The chain must then be locked with a padlock and a ‘Do not open’ warning sign displayed.
• Ensure that the pneumatic equipment has been de-compressed by attempting to start the equipment before work commences.
• On completion check if everything is in order, remove warning sign and padlock then clear the record book by signing and indicating the finishing time.
• If the person  who  installed  the  lock  is  not  available  for  any  other  reasons  a responsible competent qualified person only after he has satisfied himself that it is safe to do so may remove the lock or the responsible Head of department, may give permission in writing to a competent person to remove the lock under the following conditions:

–He/she has satisfied himself that it is generally safe to remove the lock. He/she makes an entry in the isolation record book stating the reason for his action, the name of the person to whom the permission is given and the time.

COMPRESSORS

• Make an entry in the isolation record book/compressor log book indicating the name of the compressor that you intend working on and the reason for the lock-out, location, your name and signature, date and time of the lock-out.
• Stop compressor by pressing the stop button.
• Isolate ‘control isolator’ and display a ‘men working on machine’ warning sign on control the control panel.
• Lock out isolating lever with a padlock.
• Stop the cooling pump and display a ‘men working on machine’ warning sign on control panel.
• Stop cooling tower fan and display a ‘men working on machine’ warning sign.
• Close main delivery valve.
• Open the blow off valve to de-compress the compressor.
• Ensure that the compressor is de-compressed properly and ensure the effectiveness of the lock-out by attempting to start the equipment before work commences.
• On completion check if everything is in order, remove warning signs and padlock then clear the record book by signing and indicating the finishing time.
• If the person  who  installed the  lock  is  not  available  for  any  other reasons  a responsible competent qualified person only after he has satisfied himself that it is safe to do so may remove the lock or the responsible Head of department, may give permission in writing to a competent person to remove the lock under the following conditions:

–He/she has satisfied himself that it is generally safe to remove the lock. He/she makes an entry in the isolation record book stating the reason for his action, the name of the person to whom the permission is given and the time.

SELF-PROPELLED MOBILE MACHINERY

DIESEL MACHINES

• Make an entry in the operator’s checklist and sign.
• Park SPMM on a level and safe area.
• Switch the ignition switch off and remove the key and keep such key in person or lock it away in a safe place.
• Where possible the battery master must be switched off and the arm/key removed, keep such arm/key on person or lock it away in a safe place.

ELECTRIC  MACHINES

• Make an entry in the operator’s checklist and sign.
• Park SPMM on a level and safe area.
• Switch the plug off from the supplier and remove it.
• Isolate or de-energise the power source and lock the supply switch in off position with a padlock and keep key on person. I you intend working on a trailing cable of such electrical machine, the supply cable must be isolated, disconnected and earthed.

TRACKBOUND EQUIPMENT

• Park machine on a level and safe area.
• Remove ignition key and keep key on person.
• Attempt to start the unit with an ignition key removed and where a start button is employed in order to ensure that the unit is effectively locked out.

CONVEYOR  BELT INSTALLATION

• Make an entry in the isolation record book indicating the part intend working on and the reason for the lock-out, location, your name and signature, date and time of the lock-out.
• Isolate or de-energise the power source and lock with a padlock.
• Where the conveyor belts installation is sequence interlocked or starts automatically, the other equipment must also be isolated where the possibility exists that such equipment may cause injury to persons.
• Display a ‘Do not start’ warning sign on the power source.
• Ensure the effectiveness of the lock out by attempting to start the conveyor belt before work commences.
• Pull the trip cable in the area where the work is to be carried out.
• On completion check if everything is in order and that all guards have been put back into their designed positions and fastened, remove warning sign and padlock then clear the record book by signing and indicating the finishing time.
• If the person  who  installed  the  lock  is  not  available  for  any  other  reasons  a responsible competent qualified person only after he has satisfied himself that it is safe to do so may remove the lock or the responsible Head of department, may give permission in writing to a competent person to remove the lock under the following conditions:

–He/she has satisfied himself that it is generally safe to remove the lock.

–He/she makes an entry in the isolation record book stating the reason for his action, the name of the person to whom the permission is given and the time.

WINCH INSTALLATION

• Make an entry in the operator’s checklist and sign.
• Winch operators shall be responsible to ensure that unauthorised operating of winch is prevented.
• The operator shall not leave the winch unless power is switched off and locked out and the lock-out key shall be kept by the operator in person.
• When any other work has to be conducted on winch by any other person the operator in charge shall be responsible for locking winch out until work is finished.

EQUIPMENT WITHOUT LOCKING OUT FACILITIES

• Entries may be made in a book provided for that purpose or checklist where applicable.
• Where locking out facilities are not feasible, the hazard must be neutralised by some other effective means.
• A competent person must physically disconnect the unit from the energy source.
• Pressurised lines must be bled to relieve the pressure, and valves must be firmly closed and a chain bolted or passed through the hand-wheel and secured to the structure in such a way that the hand-wheel cannot turn.
• Apparatus/equipment must be spragged or tied down to prevent any inadvertent movement.

GENERAL LOCKOUT SAFETY PRECAUTIONS

• Only a competent person who intends to work on the equipment or machinery shall be responsible for the locking out of such equipment or machinery.
• The isolation record book shall be kept in a safe place and shall be scrutinised by the Head of department at intervals not exceeding 3 months.
• When more than one person is required to take charge of work on a machine or equipment, each person is to fit his own padlock to the lock out device to ensure his own safety and that of his sub-ordinates.
• All electrical equipment must be provided with a padlock type stop push button for an effective application of the lock out procedure.
• Where the possibility of conductors becoming energized by induction or from another source (sequence interlocking, ring feeds and HT overhead lines), the added precaution of earthing the isolated section of the circuit must be taken.
• Multi-lock callipers shall be used where more than one person has to work on the unit or equipment that has been locked out.
• All padlocks used for locking out equipment, to have only one spare key, which shall be kept by the responsible Head of Department.
• All locks and keys used for lock out procedure to be numbered for identification purposes and shall not be used for any other purpose.
• All warning signs used for the lock out procedure shall be colour coded per occupation, in colours that will be determined by the responsible Head of department.
• When, for any reason, the lock out device is found inoperative, or in an unsafe condition, the responsible electrician shall be called to correct the fault or to physically disconnect the machine from its point of supply.