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ES&H Manual
Chapter 6230 Electronic Equipment Safe Work Program
This chapter and its associated appendices are written to outline Jefferson Lab's programs and procedures to satisfy the requirements of 10 CFR 851-Worker Safety & Health Program.

All work on electronic equipment is classified according to equipment Class and work Mode. Work performed at Jefferson Lab within these Class and Mode configurations is done in accordance with the programs and procedures. Equipment defined as AC Utilization Equipment is also covered.

NOTE: Work performed on building services electrical equipment is covered in ES&H Manual Chapter 6220 AC Electrical Equipment Safe Work Policy.

Work performed on electronic equipment exposes workers to potential electrical hazards that may result in serious injury or death. These hazards include; shock, arc flash, arc blast and other physical injury due to reactions to unexpected energy release. The program in this chapter defines the training requirements and some basic work rules, based on the equipment Class and the work Mode, which must be followed when doing work on electronic equipment. Worker qualification levels are identified as well as information on the use of work planning and Work Control Documents. Work that is permitted is identified along with some work that is not allowed.


T1 Determining Equipment Class and Work Modes
The work rules for electronic equipment are dependent on both the equipment Class and the work Mode. Training requirements and the necessity for Work Control Documents are determined by an evaluation of the Class and Mode. The Class, Mode, and minimum work rules are determined based on the information in ES&H Manual Chapter 6230 Appendix T1 Determining Equipment Class and Work Modes.
T2 Work Planning and Execution for Electronic Equipment Safety
The work rules for electronic equipment are dependent on both equipment Class and work Mode. Workers must determine the training requirements and applicable work rules once the equipment Class and work Mode are identified. The required steps for turning a work assignment into a work plan can then be determined. ES&H Manual Chapter 6230 Appendix T2 Work Planning and Execution for Electronic Equipment Safety provides an outline for determining the steps necessary to plan work on this type of equipment, identify the hazards, and develop work controls.

Supplemental Material:

NFPA 70E - Standards for Electrical Safety in the Workplace
NFPA 70 - National Electric Code
OSHA Regulation 29 CFR 1910 Subpart S and 29 CFR 1926 Subpart K
DOE Electrical Safety Handbook


Management authority may be delegated at the discretion of the responsible manager.

Qualified Electronic Worker
  • Ensure required training is maintained and current (see Qualifications/Requirements listed below).
  • Prior to doing work, perform an informal hazard analysis to determine equipment Class and work Mode.
  • If necessary perform a Task Hazard Analysis and file a work planning document (for example ATLis or FEList).
  • Ensure authorization is received prior to beginning work.
  • Ensure work is performed at the lowest energized state commensurate with accomplishing the task.
  • Ensure that all medium and high risk work (identified as Mode 2 and above on Class 2 or Class 3 equipment) follows an approved, current, Work Control Document.
  • Ensure each Mode 3 task on Class 2 or Class 3 electronic equipment is authorized under an Energized Electrical Work Permit (EEWP), approved by the Laboratory Director before beginning work.
  • Ensure that only qualified individuals service electronic equipment and that the work is accomplished as specified in this manual.
Supervisor/Subcontracting Officer's Technical Representative (SOTR)/Sponsor:
  • Conduct briefings on:
    • work hazards of Risk Code 2 or greater,
    • procedures,
    • PPE,
    • control of hazardous energy sources, or
    • any special precautions associated with planned work.
  • Ensure only qualified and trained personnel are assigned to electronic equipment work and the training level is consistent with the minimum requirements for the equipment Class and work Mode.
  • Provide a list of qualified workers to the Department Manager and the Environmental, Safety, Health, and Quality (ESH&Q) Electrical Safety Engineer.
  • Line supervisors are trained as qualified workers at the same level, or above, as those they supervise.
  • Maintain a list of workers who are qualified and authorized to work on Class 1 equipment, performing Mode 2 and Mode 3 tasks.
  • Maintain a list of workers who are qualified and authorized to work on Class 2 and Class 3 electronic equipment.
  • Review and recommend for approval all EEWPs and Work Control Documents for work on Class 2 and Class 3 electronic equipment to be performed by department workers.
Associate Director/Division Head
Laboratory Director
  • Approve all EEWPs for Mode 3, Class 2 or Class 3 work on electronic equipment.


The hazard exposure and consequent risks are determined by the equipment Class and the work Mode (see ES&H Manual Chapter 6230 Appendix T1 Determining Equipment Class and Work Modes).

A graded approach, based on Classes and Modes, is used to determine training requirements and worker qualifications required for performing work on electronic equipment. Listed below are the minimum requirements. Supervisors, or other organizational groups, may specify more stringent rules.
Mode 1 Work Only Equipment fully de-energized
Workers who are not qualified may work on electronic equipment (e.g. - mechanical technician can change magnet cooling hoses; a vacuum technician can change a pump motor); if they comply with the following rules:
  • They have current SAF104 - Lock, Tag, and Try training.
  • They witness/observe the "safing-out" of the equipment to be worked on.
  • They apply their Lock-Out device to the de-energized piece of equipment.
  • Work is approved and authorized.
Only qualified workers perform Lock-Out on Class 2 or Class 3 equipment. Lock-Out of Class 2 and 3 equipment must be done by qualified workers. Exceptions to this rule are:
  • If the equipment is equipped with a plug type power connector and the worker has been trained on, and utilizes the equipment specific lock, tag, and try (LTT) procedure.
  • If the purpose of the lock out is to perform non-electrical work where the worker will not be exposed (or potentially exposed) to any electrical shock or arc hazards during lock out or conducting the work. Also the worker must be trained on the equipment specific LTT procedure.

REMINDER: A zero voltage test, as in the "Try" portion of LTT, is a Mode 2 operation, when a Voltage Verification Unit (VVU) is not present, and constitutes exposure – see ES&H Manual Chapter 6230 Appendix T1 Determining Equipment Class and Work Mode)

Mode 2 and 3 Work on Class 1 Equipment
Class 1 equipment is considered low hazard and is a low risk for injury. As a result, training requirements are less stringent. Work is allowed at all work Modes on Class 1 equipment if the worker has the following training and requirements:
Mode 2 Work on Class 2 and Class 3 Equipment
Class 2 and Class 3 equipment are considered medium and high hazard respectively. Mode 2 involves testing and measuring of energized equipment with normal protective barriers removed and potentially bypassed interlocks. Workers performing Mode 2 work are exposed to operating voltages and currents that can cause serious injury or death. As a consequence, the knowledge and training required to perform Mode 2 work is more stringent.

NOTE: The "Try" process in the LTT lockout procedure is considered a Mode 2 operation, if protective barriers (covers, doors, etc.) are removed in order to take a measurement. Use of an installed VVU is not considered a Mode 2 operation.

The following is required for Mode 2 work on Class 2 and Class 3 equipment:
  • SAF104 - Lock Tag and Try
  • SAF603A - Electrical Safety Awareness
  • SAF603S - Switching of Electrical Equipment
  • SAF105 - CPR/AED Use
  • Demonstration of satisfactory understanding (to person authorizing the work) of the following:
    • Proper use of precautionary techniques
    • Proper use of PPE (including shock and arc flash insulation and shielding materials)
    • Proper use of insulated tools and equipment
    • Skills and techniques necessary to distinguish exposed energized parts from other parts of electronic equipment
    • Skills and techniques necessary to determine the nominal voltage of exposed energized live parts
    • Decision making process necessary to determine the degree and extent of the hazard and the PPE and job planning necessary to perform the task safely
    • Shock hazard boundaries and distances for voltages to which the worker will be exposed
Mode 3 Work on Class 2 and Class 3 Equipment
Mode 3 work is defined as manipulative operations on an energized circuit. This may include re-wiring or replacing components in an energized piece of equipment. In general this is not usually necessary for any reason in electronic equipment at Jefferson Lab. In the event that Mode 3 work is required on Class 2 or Class 3 equipment special rules apply:
  • Training identical to that required for Mode 2 work on Class 2 and Class 3 is required
  • Mode 3 work is to be performed under a task specific Work Control Document approved by the cognizant Department Head and Associate Director.
  • An EEWP approved and signed by the Laboratory Director for the specific task is required. The EEWP shall justify the reason(s) why the work has to be performed with the equipment energized.
Document Control:
    APPROVAL DATE:   06/08/17
  • REVIEW DATE:  06/08/20
    Revision 2 - 06/08/17: Updated TPOC from B.Merz to T.Kujawa; updated training requirements to reflect current laboratory operations.
    Periodic Review - 11/10/14: No changes per B. Merz
    Periodic Review - 11/27/11: No changes required at this time. Minor edits to reflect current ES&H Manual format.
    Revision 1 - 12/10/08: Update to reflect current laboratory operations.

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. .