6110 Appendix T1
Lock, Tag, Try (LTT) Procedure
This appendix contains the guidelines for locking and tagging out of hazardous energy sources when maintenance or service work is to be performed. Lock, Tag, Try (LTT) references in this appendix applies to maintenance, service, and construction applications. Refer to ES&H Manual Chapter 6111 Administrative Control Using Locks and Tags for administrative configuration control applications.
NOTE: Management authority may be delegated at the discretion of the responsible manager.
· Maintain appropriate LTT training (SAF 104 Lock, Tag, Try).
· Obtain specific LTT training on equipment being serviced.
· Perform LTT procedure process steps (listed below) only after authorization from the supervisor of the equipment which requires the securing of the hazardous energy source.
· Only assign Qualified Taggers, and provide equipment-specific LTT training, for equipment under your authority.
· Maintain familiarity with Jefferson Lab's LTT programs and procedures. (If you supervise employee(s) who use LTT procedures.)
· Perform inspections for compliance with lock and tag procedures as part of regular supervisory oversight.
· Maintain LTT qualifications. (If they supervise subcontractors who perform LTT on site.)
· Provide equipment-specific LTT procedures to subcontractors on an as needed basis.
· Verify that long-term service subcontractors are trained as Jefferson Lab Qualified Taggers and that their training is current.
· Implement group LTT and act as Group LTT Coordinator in accordance with ES&H Manual Chapter 6110 Appendix T3 Group Lock, Tag and Try Procedure if Jefferson Lab employee(s) and subcontractor(s)s are concurrently working on the same equipment/system.
· Review and approve subcontractors’ Lockout/Tagout program. Ensure that:
o Construction – subcontractors’ program meets or exceeds the requirements of OSHA 29 CFR 1926 Construction Industry Regulations, when doing construction type work activities.
o Maintenance subcontractors’ program meets or exceeds the requirements of OSHA 29 CFR 1910 General Industry Regulations, when doing service or maintenance on machines or equipment.
Only Qualified Taggers may perform the following process steps.
When service or maintenance is to be performed by multiple Qualified Taggers refer to ES&H Manual Chapter 6110 Appendix T3 Group Lock, Tag, Try (LTT) Procedure.
Step 1: Determine the Hazards
Perform or review the work’s Task Hazard Analysis.
· Evaluate the type and magnitude of the potentially hazardous energy, and the means of controlling the energy.
· Review specific equipment, written procedures, blueprints, system diagrams, valve lineups, and operating manuals.
· Confer with people who know the equipment.
· Be alert to multiple energy sources.
· Do not proceed until knowledge of the hazard(s) are known.
Step 2: Determine the Need for a Written Work Control Document
LTT applications require a written Work Control Document (see ES&H Manual Chapter 3310 Operational Safety Procedure Program), unless all of the following elements exist:
· The equipment has no potential for residual, stored, or the re-accumulation of stored, energy after shutdown.
· The equipment has a single energy source which can be readily identified and isolated.
· The isolation and locking out of the energy source completely de-energizes and de-activates the equipment.
· The equipment is isolated from its energy source and locked out during servicing and maintenance.
· A single lock out device will achieve a locked out condition.
· The lockout device is under exclusive control of the authorized employee performing the servicing or maintenance.
· The servicing or maintenance procedure does not create hazards for other employees.
· There is no record of incidents involving the unexpected activation or re-energization of the equipment during servicing or maintenance within Jefferson Lab.
Step 3: Coordinate Work/Notify Others
· Notify all affected individuals; inform them that the equipment will be placed out of service until work is completed. Coordinate work with system owners, building managers or safety wardens as deemed necessary.
NOTE: It may be more practical and safer to perform voltage verification before applying locks/tags to the isolation device. If this is the case secure the equipment and proceed to Step 6. Once a de-energized state has been verified, come back to Step 4 and continue with the LTT process.
Step 4: Isolate Energy Sources
· Don appropriate personal protective equipment (PPE).
· Secure the equipment:
o Put all appropriate energy-isolating devices in a safe state (usually “off”).
· Secure the energy source using a Jefferson Lab approved LTT lock. (A multi-lock hasp is used if there is a possibility that other employees may attempt to operate the equipment or system.)
NOTE: If the equipment is un-lockable see 4.2 Special Tag Out Situations Without Locks
· Attach a “DANGER” tag.
o The tag must be:
§ Legible - Indicating the identity of the person who applied the device(s).
§ Attached by durable means to the shackle of the accompanied lock, or a non-reusable method capable of withstanding a 50-pound pull, minimally equivalent to a nylon cable tie.
Step 5: Remove and Release Potential Energy:
· Don appropriate PPE.
· Refer to Step 6 for the removal of stored/residual electrical energies.
· Put all control mechanisms into a safe state and lock controls where possible.
· Bleed the system of energy.
· Block raised dies, gears, or equipment that could descend or move when the energy is removed.
· Lower suspended loads to the floor or secure them independently.
· Release any stored spring tension.
· Check the system for possible re-accumulation of stored energy. Continue this check until the possibility of re-accumulation no longer exists, or until the LTT is cleared.
Step 6: Verify Lockout and Try (Attempt to Restart)
· Don appropriate PPE.
· Assume the equipment is energized, or charged, until it has been determined to be de-energized.
· Witness the verification of a de-energized state.
o All Qualified Taggers having applied a personal lock and/or tag are required to perform or witness the verification of the de-energized state (refer to ES&H Manual Chapter 6110 Appendix T3 Group Lock, Tag, Try (LTT) Procedure for any exceptions to this step).
· Verify the integrity of your lockout
· Try to restart the equipment.
o Have an authorized employee attempt to operate the equipment controls, or otherwise verify the equipment cannot be restarted. Return operating controls to the safe (usually “off”) position.
For electrical energies:
· Test the metering equipment for proper operation (immediately before verifying a de-energized state).
· Verify incoming power has been de-energized.
· Test the metering equipment for proper operation (immediately after verifying a de-energized state).
· Remove and release stored energy:
o Use a grounding/shorting stick to dissipate any stored/residual energy.
o Ground the electrical components/circuits as required for the duration of the job or task.
o Verify that the stored/residual energy has been dissipated.
NOTE: In the event of a scenario where the energy source is not present during the lockout/tagout, additional safety measures are implemented to eliminate inadvertent energization. These additional steps are performed to ensure that the failure of any energy isolation device does not energize the equipment being worked on.
A written and approved Task Hazard Analysis is required under this no-energy lockout scenario, and the approval of the task includes a review from a second individual familiar with the equipment being lockout.
Step 7: Perform the Work
· Periodically re-check the integrity of the lock and/or tag, minimally:
o When there is a possibility of energy build up.
o When tasks last more than one shift.
Step 8: Prepare to Re-Energize
· Ensure the equipment has been properly re-assembled:
o Electrical jumpers and grounds, tools, work aids, spare parts and other such devices have been collected and removed, and
o Personnel have moved to safe positions.
· Close all cabinets and panels completely.
· Notify all affected individuals when work is complete and ready for energizing.
· Ensure equipment/control switches are in a safe state (usually “off”). This will:
o Avoid unexpected startup.
o Prevent inadvertent overload of circuit breakers and switches.
o Ensure safe start-up sequencing.
Step 9: Remove Locks and Tags
· Each Qualified Tagger removes their lock(s) and/or tag(s). (Refer to ES&H Manual Chapter 6110 Appendix T2 Special Lock and Tag Removal Procedure, for any exceptions to this step.)
Step 10: Energize
· Be prepared to shutdown the equipment immediately if needed. Enlist the help of others as necessary.
· Test equipment to verify proper operation.
· If testing indicates the equipment must undergo LTT again, go back to Step 3.
LTT requirements do not apply to electrical equipment that is equipped with cords and receptacle plugs if removing the plug completely de-energizes the equipment and the plug is under exclusive control at all times. Unload the equipment prior to unplugging the cord-and-plug. If these conditions cannot be guaranteed, then LTT measures are required.
NOTE: There are lockable “boots” available to secure electrical plugs.
Jefferson Lab, in accordance with OSHA and NFPA 70E standards, permits the use of tags alone in certain limited situations. To be a candidate for a tag-only control, an energy source must meet all of the following criteria:
· Equipment design precludes the installation of a lock on an energy isolation device(s).
· At least one additional safety measure is employed that provides a level of safety equivalent to that obtained by use of a lock.
· The LTT procedure to be used is documented in a work control document.
5.0 Revision Summary
Revision 1.2 – 09/10/12 – Removed Special Lock-out Situations without Tags in response to CATS item MOA-2012-19-01-01.
Revision 1.1 – 12/01/11 - Clarification of process steps and updates made to format. Qualifying periodic review, no substantive changes required.
Revision 1 – 04/04/09 – Update to reflect current laboratory operations.