TITLE:

ES&H Manual

 

DOCUMENT ID:

6110 Appendix T1

Lock, Tag, Try (LTT) Procedure

 

 

1.0            Purpose

 

This appendix contains the guidelines for locking and tagging out of hazardous energy sources when maintenance or service work is to be performed.  LTT references in this appendix apply to maintenance, service, and construction applications.  Refer to ES&H Manual Chapter 6111 Administrative Control Using Locks and Tags for administrative configuration control applications.

 

2.0            Process Steps

 

Step 1:     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 stored or residual energy or re-accumulation of stored energy after shutdown which could endanger employees;

·         The equipment has a single energy source which can be readily identified and isolated;

·         The isolation and locking out of the energy source will completely de-energize and de-activate the equipment;

·         The equipment is isolated from the energy source and locked out during servicing and maintenance;

·         A single lockout 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 does not create hazards for other employees; and

·         There is no record of incidents involving the unexpected activation or re-energization of the equipment during servicing or maintenance within Jefferson Lab.

 

Step 2:     Determine the Hazards

Work Control Documents require a hazard analysis (see ES&H Manual Chapter 3310 Operational Safety Procedure)

·         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 3:     Coordinate Work/Notify Others

·         Notify all affected employees; 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.

 

Text Box: 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”),

o   secure the equipment if the device is lockable (using a lock approved by Jefferson Lab), and

o   attach a “DANGER” tag.

o   attempt to operate the energy isolation device to ensure that operation is prohibited

·         Danger tags must be attached by a non-reusable, durable means capable of withstanding a 50-pound pull, at least equivalent to a nylon cable tie.  Tags can be attached by the shackle on the accompanied lock.

·         At a minimum either the personal maintenance lock(s) and/or danger tag(s) must legibly indicate the identity of the person who applied the device(s).

·         A multi-lock hasp is used if there is a possibility that other authorized employees will be working on the same equipment or system.

·         When service or maintenance is performed by multiple individuals, (Refer to ES&H Manual Chapter 6110 Appendix T3 Group Lock, Tag, Try (LTT) Procedure for any exceptions to this step.)

o   each qualified tagger working on the equipment must verify the lockout and removal of energy, and

o   install their own Jefferson Lab approved lock(s) and danger tag(s) at each energy control point.

 

Text Box: NOTE: Exceptions to the use of a tag are discussed in Section 3.0 Exceptions to the Use of a Lock and/or Tag. NOTE: Exceptions to the use of a lock are discussed in the in Section 3.0 Exceptions to the Use of a Lock and/or Tag.

 

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 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 operate the equipment controls, or otherwise verify the equipment cannot be restarted.  Return operating controls to the safe (usually “off”) position.

·         When working with electrical energies:

o   Verify incoming power has been de-energized. 

o   If the circuit tested is over 600 volts, nominal, then test the metering equipment for proper operation immediately after verifying a de-energized state.

o   Remove and release stored energy:

§  Use a grounding/shorting stick to dissipate any stored/residual energy. 

§  Ground the electrical components/circuits as required for the duration of the job or task. 

§  Verify that the stored/residual energy has been dissipated.

 

Text Box: 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:

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.

 

Step 9:     Remove locks and tags

·         Each tagger removes their own locks and/or tags.  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.

 

3.0            Exceptions to the Use of a Lock and/or Tag

 

3.1              Cord & plug electrical equipment

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.  

 

Text Box: NOTE: There are lockable “boots” available to secure electrical plugs.

 

3.2              Special Lockout Situations Without Tags

The OSHA and NFPA 70E standards and Jefferson Lab policy for LTT permit the use of locks alone for simple procedures.  In particular, if the locks are easily identifiable as a lockout device and has the name of the individual applying the lock, use of a lock alone is permissible if the following three criteria are met:

·         Only one circuit or piece of equipment is de-energized, and

·         The lockout period does not exceed the work shift, and

·         Employees who are exposed to the hazards associated with the reenergizing of the circuit or equipment are familiar with this procedure.

 

Text Box: NOTE: Section 3.2 Special Lockout Situation Without Tags does not apply when the work is defined as construction work. Controls that are to be de-energized during the course of construction work are locked and tagged.

 

3.3              Special Tagout Situations Without Locks

The OSHA and NFPA 70E standards and Jefferson Lab policy for LTT permit the use of tags alone in certain limited situations.  To be a candidate for a tag-only control of an energy source, the situation shall meet all of the following criteria:

·         Equipment design precludes the installation of a lock on an energy isolation device(s), and

·         At least one additional safety measure is employed that provides a level of safety equivalent to that obtained by use of a lock.

 

 

 

 

ISSUING AUTHORITY

CHAPTER AUTHOR

APPROVAL DATE

EFFECTIVE DATE

EXPIRATION DATE

REV.

 

 

 

ESH&Q Division

Todd Kujawa

04/04/09

04/04/09

04/04/12

1

 

This document is controlled as an on line file.  It may be printed but the print copy is not a controlled document.  It is the user’s responsibility to ensure that the document is the same revision as the current on line file.  This copy was printed on 10/13/2009.