By Jim Phillips, P.E.
International Chairman IEC TC 78
As the International Chairman of IEC TC 78, a frequent question that I receive is “What is IEC TC 78?”
IEC is the acronym for the International Electrotechnical Commission based in Geneva, Switzerland. TC 78 standards for Technical Committee 78 which is the Live Working Committee. This committee is responsible for over 40 different International Live Working standards and documents and is represented by 42 countries via National Committees which includes 136 individuals known as Experts. Before I go any further, let’s back up a few steps first.
IEC – International Electrotechnical Commission
Founded in 1906, the IEC (International Electrotechnical Commission) based in Geneva, Switzerland, is the world’s leading organization for the preparation and publication of International Standards for all electrical, electronic and related technologies.
IEC provides a platform to companies, industries and governments for meeting, discussing and developing the International Standards they require.
All IEC International Standards are fully consensus-based and represent the needs of key stakeholders of every nation participating in IEC work. Every member country, no matter how large or small, has one vote and a say in what goes into an IEC International Standard.
The IEC is one of three global sister organizations (IEC, ISO, ITU) that develop International Standards for the world. When appropriate, IEC cooperates with ISO (International Organization for Standardization) or ITU (International Telecommunication Union) to ensure that International Standards fit together seamlessly and complement each other. Joint committees ensure that International Standards combine all relevant knowledge of experts working in related areas.
TC 78 / Technical Committee 78 – Live Working
From the official scope of IEC Technical Committee 78 it is:
To prepare International standards for tools, equipment and devices for utilization in Live Working, including their performance requirements, care and maintenance.
Excluded: Work practices and methods for Live Working.
To prepare technical publications related to the utilization of tools, equipment and devices on, and in the vicinity of, live parts of electrical installations and systems.
In simple terms, if it is a tool, equipment etc. for use in Live Working, TC 78 is likely the place where you find a standard for it.
Live working sometimes referred to as Live-line working is where the maintenance of electrical equipment and systems is performed while the equipment is energized – this includes transmission voltages in the 100’s of thousands of volts – INCLUDING BAREHAND WORK!
The first techniques for live-line working were developed in the early 1900’s and both equipment and work methods were later refined to deal with increasingly higher voltages. In the 1960s, methods were developed in the laboratory to enable field workers to come into direct contact with high voltage lines. Such methods can be applied to enable safe work at the highest transmission voltages.
Live Working methods can be applied to enable safe work at the very highest transmission voltages. “Bare-Hand” and/or ‘Live-Line” is the method whereby a worker is placed at the same potential as, and works directly on energized conductor or equipment. The transfer of the worker to conductor potential may be accomplished through the use of insulated ladders, live line rope, insulated EPV personnel buckets or helicopters.
The live-line barehand technique is used to work high voltage lines (generally 115 kV and higher) while they are “live.” Since insulating gloves are not available for these voltages, the technique of bare-hand live line work has been developed in which the worker is bonded to the line, working, insulated and/or isolated from ground and all other objects at a different potential.
With the metallic mesh clothing bonded to the conductor, the lineman can work protected inside the electrical field. Conductive Clothing creates a Faraday cage effect that places a linesman at the same potential as the conductor. Metallic mesh clothing? Yes, and IEC TC78 has a standard for it – and many other standards as well!
IEC TC78 Live Working Standards and Documents
Below is a list of the standards and documents that are developed and maintained by IEC TC78.
- IEC 60743:2013 ED3 Live working – Terminology for tools, devices and equipment
- IEC 60832-1:2010 ED1 Live working – Insulating sticks and attachable devices – Part 1: Insulating sticks
- IEC 60832-2:2010 ED1 Live working – Insulating sticks and attachable devices – Part 2: Part 2: Attachable devices
- IEC 60855-1:2016 ED2 – Live working – Insulating foam-filled tubes and solid rods – Part 1: Tubes and rods of a circular cross-section
- IEC 60895:2002 ED2 Live working – Conductive clothing for use at nominal voltage up to 800 kV a.c. and +/- 600 kV d.c.
- IEC 60900:2012 ED3 – Live working – Hand tools for use up to 1 000 V a.c. and 1 500 V d.c.
- IEC 60903:2014 ED3 – Live working – Electrical insulating gloves
- IEC 60984:2014 ED2 – Live working – Electrical insulating sleeves
- IEC 61057:2017 ED2 – Live working – Insulating aerial devices for mounting on a chassis
- IEC 61111:2009 ED2 – Live working – Electrical insulating matting
- IEC 61112:2009 ED2 – Live working – Electrical insulating blankets
- IEC 61219:1993 ED1 – Live working – Earthing or earthing and short-circuiting equipment using lances as a short-circuiting device – Lance earthing
- IEC 61229:1993 ED1 – Rigid protective covers for live working on a.c. installations
- IEC 61229:1993/AMD1:1998 ED1 – Amendment 1 – Rigid protective covers for live working on a.c. installations
- IEC 61229:1993/AMD2:2002 ED1 – Amendment 2 – Rigid protective covers for live working on a.c. installations
- IEC 61230:2008 ED2 – Live working – Portable equipment for earthing or earthing and short-circuiting
- IEC 61235:1993 ED1 – Live working – Insulating hollow tubes for electrical purposes
- IEC 61236:2010 ED2 – Live working – Saddles, stick clamps and their accessories
- IEC 61243-1:2003 ED2 – Live working – Voltage detectors – Part 1: Capacitive type to be used for voltages exceeding 1 kV a.c.
- IEC 61243-1:2003/AMD1:2009 ED2 – Amendment 1 – Live working – Voltage detectors – Part 1: Capacitive type to be used for voltages exceeding 1 kV a.c.
- IEC 61243-2/AMD2:2002 ED1 – Amendment 2 – Live working – Voltage detectors – Part 2: Resistive type to be used for voltages of 1 kV to 36 kV a.c.
- IEC 61243-3:2014 ED3 – Live working – Voltage detectors – Part 3: Two-pole low-voltage type
- IEC 61243-5:1997 ED1 – Live working – Voltage detectors – Part 5: Voltage detecting systems (VDS)
- IEC TR 61243-6:2017 ED1 – Live working – Voltage detectors – Part 6: Guidelines on non-contact voltage detectors (NCVD) for use at nominal voltages above 1 kV AC
- IEC 61318:2007 ED3 – Live working – Conformity assessment applicable to tools, devices and equipment
- IEC TR 61328:2017 ED3 – Live working – Guidelines for the installation of transmission and distribution line conductors and earth wires – Stringing equipment and accessory items
- IEC 61472:2013 ED3 – Live working – Minimum approach distances for a.c. systems in the voltage range 72,5 kV to 800 kV – A method of calculation
- IEC 61477:2009 ED2 – Live working – Minimum requirements for the utilization of tools, devices and equipment
- IEC 61478:2001 ED1 – Live working – Ladders of insulating material
- IEC 61478:2001/AMD1:2003 ED1 – Amendment 1 – Live working – Ladders of insulating material
- IEC 61479:2001 ED1 – Live working – Flexible conductor covers (line hoses) of insulating material
- IEC 61479:2001/AMD1:2002 ED1 – Amendment 1 – Live working – Flexible conductor covers (line hoses) of insulating material
- IEC 61481-1:2014 ED1 – Live working – Phase comparators – Part 1: Capacitive type to be used for voltages exceeding 1 kV a.c.
- IEC 61481-2:2014 ED1 – Live working – Phase comparators – Part 2: Resistive type to be used for voltages from 1kV to 36 kV a.c.
IEC 61482-1-1:2009 ED1 – Live working – Protective clothing against the thermal hazards of an electric arc – Part 1-1: Test methods – Method 1: Determination of the arc rating (ATPV or EBT50) of flame resistant materials for clothing
- IEC 61482-1-2:2014 ED2 – Live working – Protective clothing against the thermal hazards of an electric arc – Part 1-2: Test methods – Method 2: Determination of arc protection class of material and clothing by using a constrained and directed arc (box test)
- IEC 61482-2:2009 ED1 – Live working – Protective clothing against the thermal hazards of an electric arc – Part 2: Requirements
- IEC 62192:2009 ED1 – Live working – Insulating ropes
- IEC 62193:2003 ED1 – Live working – Telescopic sticks and telescopic measuring sticks
- IEC 62237:2003 ED1 – Live working – Insulating hoses with fittings for use with hydraulic tools and equipment
- IEC TR 62263:2005 ED1 – Live working – Guidelines for the installation and maintenance of optical fiber cables on overhead power lines
In addition, there are several new international standards and technical reports that are currently under development.
So what do we do?
So, what is IEC TC 78? To sum it up, a very busy group with experts from many countries around the world dedicated to developing standards for safer live working for tools, equipment and devices. With live working, the electrical power transmission and distribution system, can experience fewer outages and maintain better reliability.
About Jim Phillips: Electrical Power and Arc Flash Training Programs – For over 30 years, Jim Phillips has been helping tens of thousands of people around the world, understand electrical power system design, analysis, arc flash and electrical safety.
Jim is Vice Chair of IEEE 1584, International Chairman of IEC TC78 Live Working and Steering Committee Member – IEEE/NFPA Arc Flash Collaborative Research Project. He has developed a reputation for being one of the best trainers in the electric power industry. Learn More
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