8.1
Introduction
In the United States, 4,000
non-disabling and 3,600 disabling electrical contact injuries occur
in the workplace annually. 2,000 workers are sent to burn centers with
electric burns each year. Most of the burn victims become permanently
disabled from their injuries. Typically, the victim’s lives are forever
restricted due to sensitivity to cold weather, mobility, or other physical
barriers. Every day one person dies from electrical incidents.
This chapter contains general
requirements and information for all electrical work at LBNL. All employees
of the lab, participating guests, students and all subcontractors working
at the lab must comply with the requirements in this chapter.
8.2
Definitions and Acronyms
Definitions of terms used in
this chapter are included as Appendix D. Many terms used in this Chapter have meanings unique to electrical safety.
All such terms will be printed in small capitols.
Acronyms used are as follows:
EH&S: Environment,
Health & Safety
8.3
Scope
The purpose of this chapter
is to ensure the electrical safety of every employee, visiting guest
and subcontractor at the lab by:
- Defining safe work
practices and use requirements for all people who work with electrically energized equipment as part of their normal job duties.
- Establishing training
requirements for qualifying and authorizing LBNL employees who work
on or near energized electrical circuits and components.
- Establishing a process
for evaluating the electrical hazards of every energized electrical
work task and for providing commensurate hazard controls.
- Establishing a formal
process for controlling energized electrical work through an approval
process.
This Chapter applies to:
- The general LBNL
population
- Contractors and
subcontractors
- Facilities Electricians
who work on or near electrical distribution and hard-wired equipment
connections, and
- Researchers, students
and participating guests who build, modify, test or repair electric
or electronic equipment and apparatus, and
- Engineers, designers
and technicians who design, build, modify or repair electric or electronic
equipment and apparatus.
Reading this chapter does not
qualify the reader to perform electrical work. Guidelines that are beyond
the scope of this document must be established at each work area. They
should include, as a minimum, the safety concerns outlined herein.
This chapter is in no way to
be construed as a synopsis of all electrical requirements, nor as a
substitute for formal study, training, and experience in electrical
design, construction, and maintenance.
8.4
Policy
It is the policy of LBNL that:
- LBNL shall comply
with DOE and OSHA regulations, NFPA 70, National Electrical Code, NFPA
70E, Standard for Electrical Safety in the Workplace, ANSI C2, National
Electrical Safety Code (NESC), and other established safety standards
to reduce or eliminate the dangers associated with the use of electrical
energy.
- All electrically energized equipment will be used in a safe manner as intended by the
manufacturer and the NRTL listing or AHJ acceptance criteria.
- All electrical wiring
and equipment installations will comply with the National Electrical
Code, OSHA regulations, and other consensus industry standards for electrical
safety and engineering.
- All employees have
a responsibility to ensure they and others around them are working in
a safe manner with the proper equipment and hazard controls. LBNL has
a Stop Work Policy, (PUB 3000, Chapter 1.5) It is the responsibility
of everyone to exercise this policy when observing unsafe work conditions
or practices.
- All research or
test devices operating at a voltage greater than 50 volts with the ability
to produce 5mA or more of current, or having capacitors greater than
1J (joules), or 1000 Joules if less than 50 volts, must be protected
by an enclosure with secured or interlocked covers, or isolated in a
manner that will prevent inadvertent contact with exposed live parts.
- Fabrication of research
and test equipment will be done following prescribed LBNL design and
engineering requirements.
- Any potentially electrically hazardous work will be performed following Lockout Tagout
rules as described in PUB 3000, Ch. 18.
- Work will only be
performed on electrically-hazardous electrical circuits or components
when it can be demonstrated that de-energizing introduces additional
or increased hazards or is infeasible due to equipment design or operational
limitations. Energized parts not considered electrically-hazardous shall
not be required to be deenergized if there will be no increased exposure
to electrical burns or to explosion blast due to electric arcs.
Approval is required per Section 8.7.1 before approaching nearer than the limited approach boundary or arc flash protection boundary.
- When work on electrically-hazardous electrical circuits or components s is justified and approved, controls
(guards, covers, shields, insulated tools & probes, remote methods)
must be used to reduce the potential for contact with energized components.
- All employees who
work within the limited approach boundary or arc flash protection boundary of electrically-hazardous electrical
circuits or components must be qualified and authorized by a JHA, AHD
(See PUB3000, Chapter 6) or Subcontractor Electrical Safety Workbook
(See Appendix B) prior to performing such work.
- Safety related
work practices and procedures for employees who work within the limited
approach boundary or arc flash protection boundary of electrically-hazardous electrical circuits or components will be done in accordance with the
requirements of NFPA 70E, Standard for Electrical Safety in the Workplace.
- Subcontract employers
will ensure their employees comply with NFPA 70 and NFPA 70E when their
work is covered by the respective code or standard. LBNL points-of-contact
for the contract will inform the contract employer of any additional
information needed by the contract employer to perform an adequate electrical
hazard analysis for their employees and ensure a Subcontractor Electrical
Safety Workbook and if necessary, an Energized Electrical Work Permit
(EEWP) is completed.
8.5
Electrical Hazards
8.5.1
Electrical Shock
Accidental contact with
exposed electrical parts operating a voltage greater than 50 volts to
ground and having a current greater than 5 milliamperes can cause serious
injury or death. Fatal ventricular fibrillation of the heart
can be triggered by a current flow of as little as several milliamperes.
Severe injuries, such as deep internal burns, can occur even if the
current does not pass through the vital organs or nerves.
8.5.2 Delayed Effects
Damage to the internal
tissues may not be apparent immediately after contact with the current.
Delayed internal tissue swelling and irritation are possible. Prompt
medical attention can help minimize these effects and avoid death or
long-term injury.
8.5.3
Arc Flash
When an electric current
passes through the air between two conductors, the temperature can reach
35,000°F.
Exposure to these extreme temperatures can result in life threatening
burns. The majority of hospital admissions due to electrical accidents
to qualified workers are from arc-flash burns, not electrical shocks.
Arc-flashes can and do kill at distances in excess of 10 ft. Equipment that presents an arc flash hazard must be marked with a label
describing the available incident energy and level of PPE required for
work within the arc flash boundary when the equipment is energized.
8.5.4
Arc Blast
The tremendous temperatures
of the arc cause an explosive expansion of both metal and the surrounding
air in the arc path. For example, copper expands by a factor of 67,000
times when changed from a solid into a vapor. The dangers of this explosion
are of high blast pressure wave, high decibel levels of sound and high
velocity shrapnel. Finally the material and molten metal is expelled
away from the arc at speeds exceeding 700 miles per hour. Arc blasts
often cause severe injuries and death.
8.5.5
Other Burns
Other burns suffered in
electrical accidents are of two basic types: electrical burns and thermal
contact burns. In electrical burns, tissue damage (whether skin deep
or deeper) occurs because the body is unable to dissipate the heat caused
by the current flow. Typically, electrical burns are slow to heal. Thermal
contact burns are those normally experienced from skin contact with
the hot surfaces of overheated electric conductors.
8.6
Hazard Controls When Performing Electrical Work
The following hazard control
hierarchy will be used to mitigate electrical hazards before approaching
within the limited approach boundary or arc Flash protection boundary
of energized electrical conductors or circuit parts:
- Placing the electrically-hazardous conductors or circuit parts into an electrically safe work condition (see PUB 3000, Chapter 18, Lockout/Tagout).
- Applying supplemental
physical controls, such as panels, shields or barriers, to isolate employees
from the energized components.
- Administrative controls,
such as the Energized Electrical Work Permit, assignment of a Safety
Watch, and qualification training.
- Personal protective
equipment (PPE) to isolate workers from exposed hazardous electrical
conductors or circuit parts.
- Safe work practices
(safe work rules & electrical safety considerations) to support
the development of safe working habits.
8.6.1
Establishing an Electrically Safe Work Condition
Electrically-hazardous
conductors or circuit parts are considered safe when the practices described
in PUB-3000, Chapter 18, have been applied and verified using the following
procedure:
- Determine all
possible sources of electrical supply to the specific equipment.
- After properly
interrupting the load current, open the disconnecting device(s) for
each source.
- Wherever possible,
visually verify that all blades of the disconnecting devices are fully
open.
- Apply lockout/tagout
devices in accordance with PUB3000, Chapter 18.
- Use an
appropriately rated voltage detector to test each phase conductor or
circuit part both phase to phase and phase to ground to verify they
are deenergized.
- Where the possibility
of induced or stored electrical energy exists, apply grounding devices.
8.6.2 Supplemental
Physical Controls and Administrative Controls
Where it is infeasible
or where a greater hazard would be introduced by de-energizing electrically-hazardous
conductors or circuit parts, additional
physical and administrative measures to protect the worker
shall be incorporated into the work process. Examples to be considered
include (but are not limited to):
- Energized Electrical
Work Permit (See Appendix A)
- Safe Work Practices
and LBNL Electrical Safe Work Rules (See 8.6.4)
- Non-conductive
panels used as barriers. These barriers can have small openings
for tool access to allow troubleshooting, measurement, and/or calibration
of equipment with access panels open
- Rated non-conductive
insulating shields or barriers for energized components that do not need to be
exposed during the work
- Ground Fault
Circuit Interrupters (GFCI’s)
- Rated insulated barriers mats or gratings to isolate the worker from
conductive ground paths while working on exposed and energized electrical components
- Rated insulated
tools and test equipment
8.6.3 Personal Protective Equipment
(PPE)
Qualified workers who are
potentially exposed to electrical hazards that cannot be controlled
through some engineering means must be provided with and use personal
protective equipment that is appropriate for the specific work to be
performed and the associated hazard level. NFPA 70E defines PPE requirements
PPE is required for any work within the restricted approach boundary or arc flash protection boundary.
8.6.4 Safe Work Rules
Note: A summary
of the LBNL electrical safe work rules is provided below. For a more
thorough description of the safe work rules see Appendix M.
- Positively ensure
the correct circuit is identified before lockout and tagout.
- Whenever possible
deenergize the equipment before testing.
- The employee in
charge must conduct a briefing before all energized electrical work.
- Identify hazards
and anticipate problems.
- Resist “hurry-up”
pressure.
- Don’t hesitate
to use the Stop Work Policy (PUB 3000, Chapter 1.5).
- Always consider
electrical equipment energized until positively proven otherwise.
- Use suitably rated
electrical devices only as intended.
- Remove all conductive
jewelry before performing energized electrical work.
- Know how to shut
down equipment in an emergency.
- Know LBNL emergency
procedures.
- Design for safety.
- Reset circuit breakers
only after the trip problem has been corrected.
- Maintain the protection
of covers, barriers and shielding.
- Never drill into
a wall or floor slab without Facilities approval. See Admin 053 Facilities penetration Policy.
- Never modify or
penetrate premises wiring conduit or enclosed wireways. Only qualified
and authorized Facilities Department personnel are allowed to work on
premises wiring, conduits or enclosed wiring. See Section 8.8.4.
Note: For
a listing and description of other electrical safety considerations,
see Section
8.13.
8.7
Energized Electrical Work Requirements
Energized electrical work is any
activity inside the LIMITED APPROACH BOUNDARY or FLASH PROTECTION BOUNDARY of ELECTRICALLY-HAZARDOUS electrical conductors or
circuit parts. Conductors or circuit parts are considered ELECTRICALLY-HAZARDOUS if they operate at a level that could
cause injury to a worker through contact or exposure to an ARC FLASH HAZARD. Verification of absence of voltage
for LOTO is considered to be energized electrical work. Authorization
is required for all energized electrical work, but the method of authorization
differs according to the task.
It is LBNL policy to deenergize
electrically-hazardous parts, whenever possible, before an employee
works on or near them (see PUB-3000, Chapter 18, Lockout/Tagout).
This is the preferred method for protecting workers from electrical
hazards. Workers are permitted to work on or near exposed energized
electrical conductors or circuit parts only if it can be demonstrated that de-energizing would introduce additional
or increased hazards or is infeasible due to equipment design or operational
limitations. Energized parts that are not electrically-hazardous need not be deenergized if there will be no increased exposure to electrical
burns or to explosion blast due to electric arcs.
8.7.1
Electrical Work Authorization
8.7.1.1 LBNL Employees
note: The requirement for
an AHD for exposed electrical work is in a phase-in pilot program. Full
implementation will become mandatory on June 1, 2009.
electrically hazardous testing, troubleshooting, and inspection activities are authorized by
an Activity Hazard Document (AHD). Any work that is not specifically
authorized in an AHD, requires an EEWP (Appendix A). The authorization
will consider hazards for both contact and arc flash exposures.
Work requiring an EEWP
shall have a task-specific electrical hazard analysis completed and
documented on the EEWP. At a minimum, the hazard
analysis must determine:
- The voltage of all
exposed energized electrical components,
- The Shock Approach
Boundaries from NFPA 70E that will be crossed,
- The shock-protection
PPE that is necessary to prevent contact with energized components,
- The Arc Flash Protection
Boundary,
- The PPE necessary
within the Arc Flash Protection Boundary that will prevent injury should
an arc flash occur.
Depending on the risk,
complexity, or severity of the task, additional controls may be necessary.
The worker performing the task shall be qualified to recognize and avoid
any electrical hazards associated with the equipment or task.
Controls may include the need for a safety watch or second person while
the task is performed. For assistance in conducting an electrical
hazard analysis, see Appendices A, B, C, O, and Q or contact either the Division Safety
Coordinator or Electrical Safety AHJ.
8.7.1.2 Subcontractors
LBNL Subcontractors performing
any exposed electrically hazardous work shall complete a Subcontractor
Electrical Safety Workbook (Appendix B) and an EEWP (Appendix A)
8.7.2
Job Briefing
Before starting a task that might expose
a worker to an electrical hazard, a person in charge shall brief the
worker of the hazards involved, necessary PPE, work practices required,
and other information necessary to minimize the possibility of an electrical
injury. The extent of the briefing depends on the risk and complexity
of the task. If the work is authorized under an AHD the briefing
will usually consist of simple direction by the supervisor noting any
unique hazards associated with the assignment.
Work authorized by an
EEWP requires a more extensive briefing (See Appendix C for a Job Briefing
Checklist that can be used as an aid). The training and qualification
currency of the worker should be verified and any potential emergency
response actions discussed. Work should be released only when
the supervisors and all workers know the scope of the work, hazards
associated with the work, appropriate controls to manage the identified
hazards and all are confident that the work can be done safely.
8.8 Qualifying and Authorizing
Personnel
Only those persons who are
both qualified and authorized may install, fabricate, repair, test,
calibrate, or modify electrical or electronics wiring, devices, systems,
or equipment.
A qualified and authorized
person is an individual formally recognized by Laboratory Management
as:
- Having completed
the required LBNL classroom training, and
- Having sufficient
understanding of a device, system, piece of equipment, or facility to
be able to recognize and positively control any hazards it may present,
and
- Who have completed
site, area, facility, equipment and apparatus specific training, and
- Who possesses the
work experience and formal training necessary to execute the work according
to recognized and accepted technical standards, and
- Whose qualifications
are documented by his supervisor
A person can be considered
qualified and authorized with respect to certain equipment and methods
but not authorized for others.
8.8.1
General Guidelines for Qualification
Qualification for electrical
or electronics work is determined by the employee’s Supervisor, and
is based on a combination of LBNL classroom training (including required periodic retraining),
formal electrical trade, military, college or other training, work experience,
and on-the-job training. Formal training can be the completion of apprenticeship
or comparable training. Experience may be a combination of, or include,
formal technical related education courses, hand-on field or classroom
lab work that may or may not result in licenses or certifications.
On-going electrical and
electronics training must include an annual review of this Chapter and
all Appendices pertinent to the employee’s work assignment, Chapter
18 Lockout/Tagout, annual update of the employee’s JHA and AHD(s)
. For specific work requirements the supervisor may add classes to the
employee’s training course list not required by the JHA, but deemed
important by the supervisor.
8.8.2
General Guidelines For Authorization
Authorization to perform
electrical or electronics work by an employee is determined by the employee’s
Line Management and Supervision, and is based on the skills, knowledge,
and ability of the employee to perform a specific task safely and correctly.
8.8.3
Specific Qualification And Authorization Criteria
8.8.3.1
On-The-Job Training
On-the-job training for
specified equipment or classes of equipment must be documented to ensure
that training is adequate and consistent for all employees with similar
tasks. This documentation must be reviewed and approved by a person
who is knowledgeable in safe electrical work practices, and is familiar
with the hazards involved in the apparatus. This training shall cover:
- Features of the
equipment, including any specialized configuration
- Location of all
energy sources to, and within, the equipment
- Location of all
energy-isolating devices
- Techniques, tools,
and personal protective equipment (PPE) including arc-flash PPE used
for the specific equipment
- Relevant documents
such as wiring diagrams, schematics, service manuals, and operating,
testing, and calibration procedures
- The system's energy
control procedures, including energy-isolating devices, grounding and
shorting procedures, and other energy-control procedures
- Specific operations
in which energized work is anticipated (if any), and the process to
obtain authorization.
8.8.3.2
Task Specific Training Criteria
Supervisors shall use the
following guidelines to determine whether an individual is qualified
to perform specific electrical work. Different subsets of these criteria
shall be selected according to the exact nature of the task; however,
some analysis must always be performed, no matter how minor the job.
Tasks that are performed less often than once per year shall require
retraining before the performance of the work practices involved.
The supervisor shall authorize
the employee to perform the work task only if he/she is satisfied that
all relevant criteria are met. If the supervisor cannot verify an employee's
qualifications, assistance from the Engineering Division or EH&S
Electrical Safety Engineer should be obtained. As a minimum,
the documentation of an employee’s qualifications should consider:
- A description, in
detail of the scope of the work task being considered.
- The employee’s
ability to identify all possible hazards associated with this task.
- The employee’s
experience in the selection and use of test equipment for this task.
- The individual’s
ability to locate and read the appropriate engineering documents for
the equipment.
- The employee’s
knowledge of how to check the equipment calibration, condition, and
operation.
- The employee’s
knowledge of how to shut down, isolate, and verify all sources of hazardous
energy.
- The employee’s
awareness of LBNL LOTO requirements, and training in LOTO.
- The employee’s
ability to identify, interpret, and implement all applicable
codes and standards pertaining to the task.
- The employee’s
experience and training to independently distinguish correct construction
techniques from incorrect techniques.
- The employee’s
experience and training to select the correct materials and components,
and to use them in a manner consistent with their manufacture and/or
listing.
- The employee’s
ability to distinguish between appropriate and inappropriate equipment-grounding
techniques.
- The employee’s
familiarity with specific equipment-grounding requirements for this
apparatus.
- The employee’s
experience and training and ability to predict likely failure modes
of a particular construction, and to properly mitigate the effects of
such failures.
- The employee’s
familiarity with the proper use of the special precautionary techniques,
personal protective equipment, including arc-flash, insulating and shielding
materials, and insulated tools and test equipment (including instrument
limitations).
- The employee’s
knowledge of the nearest location of a telephone and how to alert the
lab’s emergency rescue personnel.
If the individual will
be permitted to work within the Limited Approach Boundary of exposed
energized parts operating at 50 volts or more the individual shall at
a minimum be additionally trained in all the following:
- The skills and techniques
necessary to distinguish exposed energized parts from other parts of electrical equipment.
- The skills and techniques
necessary to determine the nominal voltage of exposed energized parts.
- The approach distances
specified in NFPA 70E and the corresponding voltages to which the qualified
person will be exposed.
- The decision-making
process necessary to determine the degree and extent of the hazard and
the personal protective equipment (PPE) and job planning necessary to
perform the task safely.
8.8.4
Electrical Distribution Systems (Premises Wiring)
Only qualified and authorized
Facilities Department or approved subcontract personnel are allowed
to perform electrical wiring or other work directly connected to any
facility electrical distribution system (premises wiring as defined
by the NEC). Premises wiring includes that portion of utilization equipment
(see 8.8.5 below) that is permanently connected (hard-wired) to the
facility electrical distribution system, viewed from the utilization
equipment’s first disconnect (or circuit breaker) looking backward
into the premises wiring.
Connection to and diagnosis
and repair of, circuit breakers in building electrical panels may only
be done by specified qualified electrical workers.
If there is a question
about what differentiates a facility system versus utilization equipment,
consult the Electrical Safety Engineer or Facilities Electrical Shop
Supervision.
8.8.5
Research Apparatus (Utilization Equipment)
Only qualified persons may fabricate, modify, install or repair electronic or electrical equipment
used at LBNL. Supervisors are responsible for ensuring that only qualified persons under their supervision are assigned to work on electronic or
electrical equipment at LBNL. The supervisor shall ensure the qualifications
of these employees are documented. Any Laboratory worker or researcher
who performs any electrical work must complete the EHS course Basic
Electrical Hazard Awareness (EHS 260) as a prerequisite to further
specific qualifications.
8.8.6 Electrical Two-Person Rule
Certain work requires two qualified persons. This occurs when work is considered
electrically hazardous, as established by the conditions in Appendix Q
or by the work supervisor. When the "Two-Person Rule" is required,
both workers must be present at the work site, and each worker must
be aware of the other worker's tasks and must:
- Be a qualified person.
- Be able to de-energize
equipment.
- Know the location
of nearest telephones, and how to alert emergency rescue personnel.
- Be able to free
an injured worker from the hazard.
- Be trained and current
in cardiopulmonary resuscitation (CPR).
- Be trained and current
in First Aid.
- Remain in visual
and audible contact with the workers performing the work.
Note: Both
workers may perform separate work tasks so long as safety is not compromised.
8.8.6.1 Exemption To Two qualified persons
Under limited conditions,
the Electrical Two-Person Rule may allow for a second person that is
not a qualified person. All of the remaining requirements of Section
8.8.6 apply, and in addition the following must be met:
- Management must
approve this exemption.
- During the briefing
process the qualified person will assess the qualifications of the second person to determine that
the work may proceed safely.
- The second person
must be First Aid and CPR trained.
- The second person
may not enter the Limited
Approach boundary or the flash protection boundary.
- The electrical disconnecting
means must be located outside of the limited
approach boundary and the flash protection boundary.
- The electrical disconnect
must be located within 50 feet of the second
person.
- The
second person must be briefed in emergency procedures and the electrical
work being performed.
Note: This exemption only applies to the Two Person Rule, and shall not be
used when a Safety Watch is required.
8.8.7
Electrical Safety Watch
A Safety Watch is a more stringent hazard control measure than the Two-Person Rule and
must be implemented when there are grave consequences from a failure
to follow safe-work procedures. This occurs when work is considered
high-hazard electrical work, as established by the conditions in Appendix
Q or by the work supervisor. When a Safety Watch is required, the
Safety Watch must be a qualified person who is responsible for monitoring the qualified person(s)
doing the work. A Safety Watch must:
- Be a qualified person
- Have no other duties
that preclude continually observing, coaching, and monitoring for potential
hazards and mistakes
- Have a thorough
knowledge of the specific working procedures to be followed and the
work to be done; and
- Be close enough
to the work in progress to safely monitor the progress and methods of
the qualified person doing the work: the Safety Watch must use clothing
and PPE appropriate to the hazard and the distance from the work in
progress. In no case should the Safety Watch be more than 50 feet from
the qualified person (s) performing the work.
- Ensure only qualified
persons are allowed to enter the Limited Approach Boundary.
- Ensure that the
Limited Approach Boundaries are properly barricaded and controlled.
If signs and barricades do not provide sufficient warning and protection
for the Limited Approach Boundary, an attendant, (third
person), shall be stationed to warn and prevent unqualified persons
from entering.
8.8.8
Service or Maintenance Contracts (Equipment Subcontractors)
Any subcontractor
that will be performing work involving a potentially hazardous electrical
exposure shall submit a Subcontractor Electrical Safety Workbook (Appendix
B) for approval two weeks prior to beginning work at LBNL. In
addition, the specific electrically exposed tasks shall be authorized
with an EEWP.
8.9
Roles and Responsibilities
8.9.1 Authority Having
Jurisdiction (AHJ)
ELECTRICAL
SAFETY decisions are made by the Authority Having Jurisdiction (AHJ).
NFPA 70 defines the AHJ as “an organization, office, or individual
responsible for enforcing the requirements of a code or standard, or
for approving equipment, materials, an installation or a procedure.”
In an R&D environment, there are frequent situations where facilities,
equipment and work practices are developed that are not adequately addressed
by codes or standards and interpretations are necessary for work to
proceed safely. DOE has granted electrical AHJ authority to the Laboratory
Director, who has delegated this authority as follows:
Facilities and Premises
Wiring
The AHJ responsibility for the infrastructure power distribution and
premises wiring of the Laboratory is delegated to the Facilities Division
Director. The AHJ for the facilities and premises wiring interprets
the NEC (National Electrical Code, NFPA 70) and other codes and approves
electrical construction, electrical installations, and installed facilities
electrical equipment for Code compliance. The Facilities Division Director
may appoint an appropriately qualified electrical engineer to execute
this authority.
Research and Scientific
Equipment
The Engineering Division Director is delegated the responsibility as
AHJ to assure compliance with appropriate ELECTRICAL SAFETY requirements
for the design, installation, maintenance, and repair of research and
development (R&D) and scientific equipment and apparatus. The Engineering
Division Director will appoint an Electrical Engineer, which will be
delegated with this authority. The Engineering Director will apply criteria
from ANSI, UL, NFPA and other standards as appropriate to establish
the safety of equipment. LBNL specific criteria may also be developed
based on established engineering principles.
Electrical Safety--Work
Practices & Workplace Conditions
The Environment, Health and Safety Division Director is delegated the
responsibility for assuring compliance with all ELECTRICAL SAFETY requirements
that pertain to maintaining safe electrical work practices and workplace
conditions and thereby for protecting Laboratory employees, contractors
and subcontract personnel from injury or death as a result of electrical
hazards.
The AHJ for ELECTRICAL SAFETY is the Electrical Safety Engineer in the
EH&S Division, or a qualified alternate designated by EH&S Management.
The AHJ for ELECTRICAL SAFETY provides interpretations to ELECTRICAL
SAFETY requirements in 29 CFR 1910 Subpart S and 29 CFR 1926 Subparts
K and V, NFPA 70E, “Standard for Electrical Safety in the Workplace,”
and other standards and codes for worker electrical safety. The AHJ
for Electrical Safety will additionally apply the requirements of NFPA
70 in evaluating workplace conditions. The AHJ for Electrical Safety
is responsible for coordinating the electrical equipment acceptance
process.
8.9.2
Appeals
All appeals regarding electrical
and electrical safety questions must be submitted to the SRC via the
Electrical Safety Committee. These groups review the appeal and make
recommendations to the Deputy Laboratory Director for Operations for
a final decision.
8.9.3
Responsibilities
8.9.3.1 Individual Employees
Individual Employees are
responsible for their own and their coworkers’ safety. Each employee
will:
- Perform electrical
work only when the electrical hazards are identified, known to the employee,
adequately controlled, and when the employee is properly trained to
perform the task.
- Stop any activity
believed to be hazardous, using your STOP WORK AUTHORITY (PUB 3000,
Chapter 1.5) if necessary. Everyone working at the lab has this authority
and obligation to stop unsafe work.
- Attend training
as required to achieve understanding of how to work safely and to respond
to abnormal or emergency situations. No work requiring specialized training
shall be performed by employees who are not current in their required
training without Division and ESC approval.
- Notify a supervisor
of any condition or behavior that poses a potential hazard.
- Wear and use appropriate
personal protective equipment (PPE). Never perform any electrical
work without the proper PPE.
- Immediately report
any occupational injury or illness to the Medical Department and the
appropriate supervisor. This will include any electrical shock,
regardless of how minor the shock is perceived.
8.9.3.2
Supervisors
Supervisors of electrical
workers have the primary responsibility of ensuring a safe working environment.
They must;
- Assess the need
for establishing, implementing, and maintaining procedures and/or work
practices that will ensure the safe conduct of electrical work.
- Maintain a safe
work environment and take corrective action on any potentially hazardous
operation or condition.
- Ensure that approved,
maintained, and tested personnel protective equipment and clothing is
provided, available, and used properly.
- Assign only trained
and qualified employees to electrical work and personally ensure that
employees understand how to work safely by conducting a pre-job briefing
as necessary.
- Ensure that shift
routines, inspections, or surveillances that require working within
the Limited, Restricted, or Prohibited approach boundaries are conducted
by personnel qualified to work within those spaces.
- Ensure that all
injuries are treated promptly and reported appropriately.
8.9.3.3
Division Directors
Division Directors, by
virtue of the delegation of responsibility for all aspects of occupational
health and safety through line management, are responsible to the Laboratory
Director for assuring compliance with all electrical safety requirements
as defined in the procedure and pertaining to all programs, activities,
and facilities within their respective divisions or areas of responsibility.
8.9.3.4
Facilities Division Director
The Facilities Division
Director is responsible for interpretations of NFPA 70, The National
Electrical Code. The Facilities Division Director
will appoint a cognizant engineer, which will be delegated with this
authority. This engineer will:
- Ensure the designs
of electrical equipment installations are compliant with the requirements
of this procedure.
- Provide testing
and evaluation, as needed, for unique equipment.
- Provide shock hazard analysis and arc flash hazard analysis for electrical work as requested
by organizations performing electrical work.
8.9.3.5
Engineering Division
The Engineering Division
Director will nominate, from the Engineering Division, a chair for the
Electrical Safety Committee. Engineering Division electrical engineers
will:
- Under the direction
of the Electrical Equipment Inspection Program manager, provide for
the testing and evaluations, as needed, of unique non-NRTL equipment.
- Provide shock hazard analysis and arc flash hazard analysis for electrical work activities
as requested by organizations performing electrical R&D work.
- Ensure LBNL manufacturing,
installation, testing and maintenance of R&D electrical equipment
are compliant with electrical industry consensus standards.
8.9.3.6
Environment, Health and Safety Division Director
The Environment, Health
and Safety Division Director is delegated the responsibility by the
Deputy Laboratory Director for Operations for applying the Electrical
Safety Program and assuring compliance with all electrical safety requirements
that pertain to maintaining a safe working environment and protecting
Laboratory employees and contract and subcontract personnel from injury
or death as a result of electrical hazards.
The EH&S Division,
is responsible for the documentation of Lab-wide electrical safety policies
and procedures, site wide training, and field support for the implementation
of the LBNL electrical safety program. EH&S will:
- Perform periodic
assessments of electrical safety compliance at LBNL and provide feedback,
incident reports and recommendations to the Electrical Safety Committee.
- Appoint a qualified
Electrical Safety Engineer and an alternate.
- Maintain documentation
of Lab-wide electrical policies and procedures.
As the authorized representative
of the EH&S Director, the Electrical Safety Engineer has the responsibility
to ensure the acceptability of experimental electrical wiring and apparatus.
In this capacity the Electrical Safety Engineer will:
- Provide coordination
for the LBNL electrical safety program, working in close cooperation
with the LNBL Electrical Safety Committee of the Safety Review Committee.
- Evaluate existing
workplace safety by inspecting or assisting in the inspections of the
workplace for National Electrical Code (NEC) and NFPA 70E compliance.
The Electrical Safety Engineer shall have access and provide inspection
services for all LBNL workplaces, including construction and leased
operations.
- Serve as the primary
reviewer for Energized Electrical Work Permits. These work permits
require the approval of the Electrical Safety Engineer (or in his absence
his alternate).
- Provide assistance
to research divisions by evaluating the acceptability of experimental
electrical wiring and apparatus. In this capacity, the Electrical Safety
Engineer will, as needed:
- Ensure electrical
safety training course content complies with this Chapter, and ensure
qualified trainers are available if needed. Develop and revise electrical safety training as necessary.
- Review drawings,
tests, and other documentation provided by the project engineers, principal
investigators (PIs), or other responsible parties for compliance with
accepted safety criteria and code intent.
- Consult with the
appropriate specialists to verify that engineering, design, and construction
requirements have been correctly applied.
- Inspect power systems
and incidental wiring related to the experiment.
- Conduct other inspections
and analyses as necessary to verify the acceptability of the apparatus
involved.
- Serve as the first
contact AHJ within LBNL, which will provide formal interpretations of
Fed OSHA electrical safety requirements and NFPA 70E, “Standard for
Electrical Safety in the Workplace” and NFPA 70E.
- Assist
the Facilities AHJ with interpretations of NFPA 70, National Electrical
Code.
- Sits as an ex
officio member of the Electrical Safety Committee and provide administrative
and technical support as necessary and requested by the Chair to ensure
the effective operation of this Committee.
8.9.3.7
Electrical Safety Committee
The Electrical Safety Committee
(ESC) is a subcommittee of the LBNL Safety Review Committee (SRC). The
Electrical Safety Committee has the responsibility to develop and maintain
the LBNL Electrical Safety Program. The ESC will:
- Provide the SRC
with recommendations for training and requirements to implement the
program.
- Provide
the SRC with recommendations for funding of electrical safety initiatives.
- Develop and review
technical material related to the electrical safety program.
- Maintain through
review and revision, this Chapter and the technical electrical information
in Chapter 18 Lock Out/Tag Out.
- Assist line management
in the interpretations of electrical safety requirements.
- Assist in employee
training and safety awareness for electrical hazards.
- Assess the performance
of the Electrical Safety Program, including assessments, audits, inspections,
and reviews of electrical accidents and near misses.
- The ESC may be requested
to review electrical and electronic equipment and their installations
at LBNL.
8.9.3.7.1 Composition
The ESC should be comprised
of members who are knowledgeable in electrical safety, electrical systems,
electrical equipment, and electrical requirements and standards (Fed
OSHA, NFPA, NEC, and ANSI as appropriate).
8.10
Training
8.10.1
LBNL Training Courses
- LBNL course Lockout
/Tagout-OSHA (EHS 256) is required for anyone who for any reason
needs to remove shielding or barriers on electrically powered equipment.
- LBNL course Adult
Cardiopulmonary Resuscitation (EHS 123) is required for all persons
working in electrically hazard areas, and for persons serving as a Required
Safety Watch.
- LBNL course First
Aid Safety (EHS 116) is required for all persons working in electrically
hazard areas, and for persons serving as a Required Safety Watch.
- Some level of electrical
safety training such as EHS 260, EHS 249, and EHS 250 as determined
by JHA and one’s supervisor and ESC.
- Various levels of
electrical safety training are offered by the Laboratory on an as-needed
basis. Contact the LBNL Electrical Safety Engineer for classes or refresher
training.
8.10.2
Training Matrix By Job Task
|
LOTO – EHS
256 |
NFPA 70E – EHS 267 or EHS
268 |
First Aid Safety – EHS 116 |
Adult CPR – EHS 123 |
Basic Electrical Safety- EHS
260 |
Qualified Electronic Techs
– EHS 249 |
Qualified Electrician –
EHS 250 |
Facilities
Electricians |
X |
X |
X |
X |
|
|
X |
HVAC,
Plant Maintenance Technicians & Lighting Technicians |
X |
X |
X |
X |
X |
|
|
Electronic
Technicians |
X |
X |
X |
X |
|
X |
|
Other
General Lab Population performing authorized electrical
work above 50V |
X |
X |
X |
X |
X |
|
|
8.11
Recordkeeping
- Energized Electrical
Work Approvals (Briefings, Permits, Switching Tag, Specific
Procedures) shall be maintained by the supervisor of the person(s) performing
the work for at least three years.
- Energized Electrical
Work Approvals shall be made available to EH&S personnel.
- Training records
shall be kept on file for a period in accordance with LBNL records retention
policies.
- Qualification determination
records (resumes, job applications, military training records, on-the-job
training records, etc.) shall be kept on file for a period in accordance
with LBNL records retention policies.
8.12
Standards
- 29 CFR Part 1910, Occupational Safety and Health Standards, Department of Labor
- 29 CFR Part 1926, Safety and Health Regulations for Construction, Department of Labor
- California Code
of Regulations, Title 24, Part 3, California Electrical Code
- California Code
of Regulations, Title 8
- NFPA 70, National
Electrical Code
- NFPA 70E, Standard
for Electrical safety in the Workplace
- NFPA 101, Life Safety
Code
8.13 Electrical Safety Considerations
8.13.1
General Considerations
- Extension cords
are for temporary use: In general, roll-up the cord at the
end of the day. If an extension cord is required for the same
work at the same location on a continual basis, you should call Facilities
to install an additional receptacle where you actually need the power,
or move the equipment. Do not daisy-chain extension cords.
Check the cord for damage each time you use it. Electricians can
repair damaged cords.
- Personal Protective
Equipment (PPE): Treat it well. Keep it clean and oil
free. Perform an air leakage test of rated gloves before every use.
Flame Retardant (FR) clothing requires special laundering to maintain
its protection.
- Joining a job
in progress: When you are assigned to a job in progress with lockout
and tagout devices applied, you have an obligation to yourself to understand
exactly what has been locked out and verified.
- Practice proper
housekeeping and cleanliness: Poor housekeeping is a major factor
in many accidents. A cluttered area is likely to be both unsafe and
inefficient. Every employee is responsible for keeping a clean area,
and every supervisor is responsible for ensuring that his or her areas
of responsibility remain clean
- Maintain for
safety: Good maintenance is essential to safe operations. Establish
maintenance procedures and schedules for servicing and maintaining equipment
and facilities, including documentation of repairs, removals, replacements,
and disposals.
- Document your
work: An up-to-date set of documentation adequate for operation,
maintenance, testing, and safety should be available to anyone working
on potentially hazardous equipment. Keep drawings and prints up to
date: Obsolete drawings should be marked as obsolete and if maintained,
kept in a ‘Dead File”. Be certain that active file drawings have
the latest corrections. All facilities drawings are to be archived with
the Facilities Records Analyst and Control Specialist.
- Have designs
reviewed: All systems and modifications to systems performing a
safety function or controlling a potentially hazardous operation must
be reviewed and approved at the level of project engineer or above.
- Have designs
and operation verified: All systems performing safety functions
or controlling a potentially hazardous operation must be validated by
actual test procedures before being placed in service, at least once
a year, and anytime the system is suspected of malfunction. Both the
procedures and actual tests must be documented.
- Beware of wet
areas: While working with liquids (e.g., washing, mopping, and spraying),
exercise extra care to avoid contact with electrical outlets or devices.
Cover electrical openings if liquids can penetrate them. If the openings
cannot be covered, the power must be disconnected and locked. (See Chapter
18, Lockout/Tagout.)
- Choose safe test
equipment: The test equipment you use is considered personal
protective equipment. (PPE). Each instrument will have the words “CAT
I - 500V” (or the actual category and maximum working voltage)
marked near the input terminals. The CAT rating, I through IV,
refers to the instrument’s ability to withstand transient overvoltages.
Since these transients attenuate as they travel through an electrical
system, a higher CAT rated meter is required at the service entrance
to a building, and decreasing CAT ratings are required the further one
is from the entrance.
The categories and
ratings for intended service are:
- Category I:
Protected electronic equipment
- Category II: Appliances,
portable tools, branch circuit receptacles
- Category III:
Feeders, switchgear, large motors
- Category IV: Service
entrance, metering, utility transformers.
Use only approved test
leads to ensure the Category Rating the manufacturer has earned.
Use of “after market” test probes and leads may void the Category
Rating. If the test equipment is used for any kind of certification,
it must be calibrated regularly, according to the manufacturers’ maintenance
instructions. This may vary from meter to meter, but generally, recalibration
once a year is typical.
- Keep manuals,
read them: Read the manuals before assembling or operating the equipment.
These manuals are part of your safety system.
- Set meter range
switches before powering-up: Decide in advance that you will
not change ranges with a probe on a live test point. There are
two reasons for this: First, remember, it’s easy for a probe tip to
slip off a live test point while you are looking at the range switch.
Second, it may be possible to switch through a current measurement range
effectively putting a dead short between the meter leads.
- Drawings are
safety equipment: We have a special obligation to ensure all our
drawings and wire lists are accurate. We have to rely on engineering
drawings and schematic diagrams of experimental equipment to identify
sources of electrical power, diagnose operational problems, and begin
logical troubleshooting. If the drawings are not truly “as built”
(i.e., actually representative of the equipment we’re asked to work
on) we could be working in equipment with power present -- and not know
it. When you discover a discrepancy between an engineering drawing
and the actual equipment, stop and back out. If in
your judgment it is safe to continue with the existing drawings under
that judgment, do so with great caution, and on completion of the work
mark-up the drawings with the corrections needed, and advise your supervisor.
- Proximity sensors: Proximity detectors may NOT be used in the final verification
step for LOTO. Before probing a circuit with voltmeter leads
(a direct contact), use every non-contact method at your disposal to
check for zero-energy-state. You can almost always use a proximity
sensor safely, before actual probing. Proximity sensors don’t work
on DC and, sometimes not on AC. They CANNOT guarantee that a circuit
is in a zero-energy state, but they might disclose a source of AC power
that is still energized and of which you were not aware. The rule-of-thumb
is, if it indicates there is AC power present, believe it: if it indicates
there is no AC power, further testing is necessary. As with your voltmeter,
check the proximity sensor immediately before using it, then check is
again, immediately after using it to ensure it is still actually working.
- Keep proper spare
fuses handy: Check the manual for the proper fuse information. When
replacing fuses, the replacement fuse must be an exact replacement.
Using any other value or type fuse compromises the integrity and safety
of the equipment.
- Inspect your
meter and meter leads for damage before each use.
- Beware UPS Systems: Aside from internal battery voltages, Uninterruptible Power Sources
(UPS’s) are designed to provide 120-volt AC power to a computer or
other critical equipment when its plug is removed from the wall receptacle.
You should expect to encounter 120-V AC when you open it.
- Operating Circuit
Breakers: Circuit breakers may be used as switches under certain
conditions. Use the following precautions when operating a circuit
breaker for any reason.
- Stand to the side
of the distribution panel and look away when operating the handle.
Avoid reaching across the panel to operate the circuit breakers.
- Wear 100%, natural
fiber (non-synthetic) shirt. This will reduce the potential of a burn
should an arc occur.
- Circuit breakers
operating at 480 volts or more shall be operated only by qualified personnel.
- Tripped Circuit
Breakers: Circuit breakers are designed to automatically shut
off, or trip, when one of two conditions occur. The first is a defect
in the circuit or equipment causing a short circuit or ground fault.
Resetting a tripped circuit breaker into a short circuit or ground fault
condition can be extremely hazardous. The second condition is an overload
caused by too many electrical devices on the circuit. If it is
obvious that the trip was caused by an overload condition, LBNL policy
permits correcting the overload condition (i.e., unplug enough devices
to adequately decrease the load) and resetting the circuit breaker
one time, using the precautions described above. If the circuit breaker
trips again, a qualified person must be notified to conduct an investigation
before attempting to reset the circuit breaker.
- Any circuit breaker
condition not corrected as above shall be corrected only by a qualified
person. Contact Facilities or Engineering for assistance.
- Ground Fault
Circuit Interrupter (GFCI): GFCI’s are devices designed
to protect people from electrocution (death by electrical shock).
They interrupt the circuit at extremely low current levels (4-6 mA).
The NEC, OSHA, LBNL policy, and NFPA 70E require installation or use
of GFCI devices under certain conditions. GFCI’s will be installed
to protect receptacles in: bathrooms, kitchen countertops, rooftops,
outside locations, vending machines, electric drinking fountains, and
any 120 volt receptacle within 6 feet of sinks. GFCI protection
for personnel shall be used when temporary wiring (e.g. extension cord
sets) are used for activities such as: construction, remodeling, maintenance,
repair, or demolition. Additionally, GFCI protection is required
whenever personnel are working with electrical equipment in wet locations
or using heater tapes. GFCI’s should be considered whenever
there is an increased risk of electrical shock.
GFCIs must be tested
at least at 30-day intervals. Push the “test” button and observe
if the “reset” button pops out and the receptacle turns off. Verify
that the power is off by plugging in a small lamp or similar device.
If this does not happen, the GFCI is not functional and must be replaced.
CAUTION: Testing of a GFCI will disconnect all receptacles protected by
the GFCI. Before testing, determine which receptacles are protected.
Verify that the interruption of power will not adversely affect other
activities.
8.13.2 Clearance Around Electrical Equipment
Maintain access and working
clearance space around power and lighting circuit breaker panels, motor
controllers, and other electrical equipment in accordance with OSHA
or the latest edition of the National Electrical Code (NEC), whichever
is most stringent. For most equipment, this will be a space 30” wide
by 36” deep.
Clearance space must not
be used for storage or occupied by bookcases, desks, workbenches, or
similar items. Not even a wastebasket.
8.13.3
Flexible Cords
Because cord and plug connections
are generally well understood, this instruction does not cover portable
hand-operated power tools, small kitchen appliances, office equipment,
electronic instruments, personal computers, and other similar equipment.
Allowed Uses: Flexible
cords and cables may be used for:
- Pendants.
- Wiring of fixtures.
- Connections of portable
lamps or appliances.
- Elevator cables.
- Crane and hoist
wiring.
- Connecting stationary
equipment that requires frequent interchange.
- Preventing transmission
of noise or vibration.
- An appliance or
equipment with fastenings and mechanical connections specifically designed
to permit removal for maintenance and repair, and intended or identified
for flexible cord connection.
- Power cables (AC)
for data-processing equipment.
- Connecting moving
parts.
When flexible cords and
cables are used in conditions 3, 6, or 8, above, they must be equipped
with an approved attachment plug and energized from a receptacle outlet.
Only qualified persons may install cord caps, (the attachment plug),
on cords.
Flexible cord and cable,
attachment plugs, and receptacles must be of the proper type, size,
and voltage and current rating for the intended application.
Branch circuits that feed
cord-and-plug connected equipment must be designed, have overcurrent
protection and be grounded in accordance with the NEC.
All cord-and plug-connected
equipment must be grounded with a correctly sized and identified equipment-grounding
conductor that is an integral part of the ac power cord or cable. Exception: Listed equipment that is protected by a double insulation system or
its equivalent.
Forbidden Uses of Flexible
Cables:
- Substituted for
the fixed wiring of a structure.
- Run through holes
in walls, ceilings, or floors.
- Run through doorways,
windows, or similar openings.
- Attached to building
surfaces.
- Concealed behind
building walls, ceilings, or floors.
- Installed in electrical
raceways, unless specifically allowed by NEC provisions covering electrical
raceways.
Except for the temporary
wiring provisions of NEC, the NEC does not allow the cord-and-plug connection
of equipment to be energized from extension cords. Extension cords are
not legal substitutes for the fixed wiring of a structure such as a
receptacle outlet.
In industrial locations,
a suitable guard or cover must protect the interface between attachment
plug and receptacle from intrusion of process waste or other foreign
material, such as cutting oils and machining chips.
8.13.4
Extension Cords
Extension cords provide
a convenient method of bringing ac power to a device that is not located
near a power source. They are used as temporary power sources. Extension
cords are probably involved in more electrical-code and safety violations
than any other device at the Laboratory. They are stepped on, stretched,
cut, overloaded, and, in general, used improperly.
Guidelines for the Safe
Use of Extension Cords:
- Use only approved and properly maintained extension cords that have no exposed live parts, exposed ungrounded metal parts, damage, or splices.
- Use only heavy-duty
or extra-heavy-duty rated cable.
- Use extension cords
that are protected by a ground fault circuit interrupter (GFCI) around
construction sites, in damp areas, or in an area where a person may
be in direct contact with a solidly grounded conductive object (e.g.,
working in a vacuum tank). The GFCI can consist of a special circuit
breaker, a GFCI outlet, or an extension cord with a built-in GFCI.
- Ensure that the
extension cord is of sufficient current-carrying capacity to power the
device. Use of an undersized cord results in an overheated cord and
insufficient voltage delivered to the device, thus causing device or
cord failure and a fire hazard. Undersized cords also constitute a serious shock hazard as it may not allow the breaker feeding it to trip.
- Always use three-conductor
(grounded) extension cords—even if the device has a two-conductor
cord. Never use two-conductor extension cords at the Laboratory.
Avoiding Misuse of Extension
Cords: Observe the following restrictions to avoid misuse of extension
cords:
- Do not use extension
cords in place of permanent facility wiring.
- Avoid running extension
cords through doors, ceilings, windows, or holes in the walls. If it
is necessary to run a cord through a doorway for short term use, ensure
that the cord is:
- Protected from damage.
- Removed immediately
when no longer in use.
- Not a tripping hazard.
- Do not daisy chain
extension cords (i.e., plug one extension cord into another extension
cord).
- Do not overload
extension cords. Make sure that the wire size is sufficient for the
current required.
- Do not cut off the
ground pin of an extension cord or compromise the ground protection
in any way.
- Do not use extension
cords with a ground conductor that has less current-carrying capacity
than the other conductors.
- Do not use frayed
or damaged extension cords.
- Never splice extension
cords, even for a repair. If an extension cord is damaged, it may be
made into two cords, provided the proper connectors are used in a proper
manner. Only qualified personnel may install cord caps for use with
potentials greater than 50V.
- Only qualified personnel may make repairs of extension cords.
8.13.5 Relocatable Power Taps
A relocatable power tap
(also referred to as a power strip) is a variation of an extension cord,
where the cord terminates in a row or grouping of receptacles. Relocatable
power taps are commonly used in offices to provide multiple receptacles
to office equipment. In general, all rules pertaining to extension cords
also apply to relocatable power taps.
Additional considerations
are:
- Only use NRTL (e.g.
UL) labeled relocatable power taps.
- Refer to limitations
of use marked on the data plate of the device. Do not exceed the
load requirements of the device. Exceeding the load rating of
the device could introduce a fire hazard.
- Do not permanently
mount relocatable power taps to any facility surface. It is acceptable
to hang them from screws or hooks if they are manufactured with slots
or keyholes. It is acceptable to attach them with Velcro or any means
that will not require the use of a tool to remove.
- In equipment racks,
the preferred method of supplying 120/208V utility power to rack-mounted
instruments is via a special relocatable power tap specifically designed
to be rack-installed.
- Portable surge protectors
manufactured before 1998 have been known to be a fire hazard and should
be replaced when found.
- Relocatable power
taps are not approved for construction sites or for outdoor use.
8.13.6
Heating Tapes and Cords
Many experiments at LBNL
use heating tapes or cords, including many high vacuum apparatus. The
heating tapes or cords pose an electrical shock hazard if not used properly.
This advisory establishes requirements for the proper selection, care,
and use of heating tapes and cords. These guidelines also apply to heating
pads, wraps, or similar components intended to be applied directly to
laboratory apparatus. Exemptions to the below requirements must be approved
by the EH&S Electrical Safety Engineer.
This document supplements
procedures and policies found in this PUB-3000 chapter (Chapter 8, Electrical
Safety).
General Electrical
Safety Requirements for Use of Heating Tape
- Whenever possible,
use heating tapes that bear a Listing mark by UL or another Nationally
Recognized Testing Laboratory (NRTL).
- Use three-wire (grounded)
heating tape and cord systems whenever practical. Two-wire heat tapes
and cords, while allowed for use at LBNL, are inherently less safe than
three-wire systems.
- Inspect heating
tapes and cords before use and discard any that display signs of excessive
wear, fraying, or overheating. Do not repair damaged items.
- Properly ground
all conductive equipment surfaces before heating tapes are powered.
- Equipment undergoing
heating with a variable AC transformer controlled heat tape must be
monitored on a regular basis to prevent overheating of either the chamber
or the heating device.
- Heating tapes and
cords with an AC plug that can be split into two pieces must have the
plug replaced or glued together.
- Read all of the
manufacturer’s instructions before using any heating device.
- Use heat tapes only
on surfaces for which they are designed. Glas-Col® heating cords are
an example of a cord that may not be used at LBNL for any purpose but
heating glassware and non-metallic apparatus.
- If you are unsure
whether or not your heating tape or cord is approved for use at LBNL,
contact the EH&S Electrical Safety Engineer.
Heating Tape Power
Source Requirements
- A Ground Fault Current
Interrupter (GFCI) protected power source must be used. Portable
GFCI adaptors are acceptable. Before use, the GFCI must be tested:
depress the “TEST” button, verify that the “RESET” button pops
out, and then depress the “RESET” button.
- A maximum of 1920
Watts of heating capacity may be placed on a 20-amp circuit breaker.
- A maximum of 1440
Watts heating capacity may be placed on any individual power cord, receptacle,
or relocatable power tap (power strip).
Unusual Conditions
- Circuit Breaker
Trip
If a circuit breaker trips
during a heating operation, this is usually because the circuit is overloaded.
Disconnect an appropriate number of the heat tapes and reset the breaker.
If the breaker trips again, call an LBNL qualified electrical worker,
Facilities Electrical shop (x6023) or the EH&S Electrical Safety
Engineer (x4694) for help.
- GFCI Trip
If a GFCI trips during
the heating operation, it is permissible to reset the GFCI one time.
Personnel must remain clear of equipment when the GFCI is reset. If
the GFCI trips again, all of the heating tapes must be disconnected
and thoroughly inspected for damage. If the problem persists, call an
LBNL qualified electrical worker, Facilities Electrical Shop staff (x6023)
or the EH&S Electrical Safety Engineer (x4694).
- Variable Transformer
Issues
If the fuse blows in the
device, replace the blown fuse only with a fuse rated for the device.
Using a higher current fuse than rated for the device will allow overheating
and may cause a fire. Variable transformers and other control devices
for heat tape control should be periodically checked by a qualified
electrical worker for receptacle tension and proper fusing.
For More Information please
contact an LBNL qualified electrical worker, Facilities Electrical Shop
staff (x6023), or the EH&S Electrical Safety Engineer (x4694) with
any questions.