A New Low Voltage Directive: Major Changes Ahead

Moe Lamothe

Key features include a lower limit of the voltage range and specific safety-related items that must be considered for every piece of equipment.

The original Low Voltage Directive (LVD) was published in 1973 and further amended in 1993 to transform it into a new approach directive. It is now being reinvented to far exceed the requirements covered by the current harmonized electrical safety standards that are used to show compliance for placing the CE mark on products.

The expected release date is 2004 under the proposed name "Electrical Product Safety Directive" (EPSD). Much of the revised content seems to be aimed at clarifying existing requirements and adding the intent of various interpretations that have been made. Major areas of change include:

• Lowering the lower limit of the voltage range to 0 V from the present 50 V ac or 75 V dc.

• Adding very specific safety-related items that must be considered for every piece of equipment.

• Additional marking and identification requirements.

History

The original directive became law in Europe in 1973 by Publication in the Official Journal of the European Communities. This was long before the CE mark was a requirement in Europe. In 1993, the LVD was amended to bring it into compliance with the requirements for using a CE mark (Annex III) and the methods of showing compliance (Annex IV).

The mandatory compliance date for the LVD was January 1, 1997. This, in effect, made CE mark a requirement, and obtaining a certification from a notified body became optional for the manufacturer.

One of the long-standing problems with the LVD is the voltage range specified from -50 to 1000 V ac and from 75 to 1500 V dc. The upper range has not been a problem, but the lower end has left a gap. Most of the present standards use 30 V ac or 60 V dc as the lower limit to determine whether a voltage might present a shock hazard. Both the standards and the LVD have ignored the potential fire hazard at lower voltages, particularly from batteries.

A point of confusion with the existing LVD is the CE marking of components. Official interpretations have indicated that components should not be marked, but common industry practice has been to CE mark components.

The Radio and Telecommunications Terminal Equipment Directive (R&TTE) published in 1999 recognized the voltage-limit problem. Article 1-10 lowered the low-voltage limit to zero for the LVD when the R&TTE Directive is being used.

The Proposed LVD Revision

The European Commission Web site describes the reasons and process for the revision of the LVD. In short, in February 2001 the commission decided the time had come to revise the LVD. An adhoc working group consisting of relevant European stakeholders was set up to prepare a first draft amendment.

The group was asked to consider the following elements of the directive: scope and interface with other directives, safety, market surveillance and traceability, and introduction of new approach principles.

As a result of the work in this group, working documents have been prepared for further discussion. The current revision is labeled Draft 4, and some of the proposed changes include:

• Electrical components intended to be incorporated into electrical equipment or installations and designed to fulfill a function in such a way that their compliance with the essential requirements can be assessed independently are deemed to be electrical equipment for the purposes of the new directive. The new directive makes it clear that many components cannot be evaluated to this revised version. If a component can be evaluated fully for safety, then it can bear the CE mark in accordance with this directive. If it needs to be installed into other equipment to be properly evaluated, then it can't be marked with the CE mark unless there is some other applicable directive. A new approach directive must always be used as the basis for placing a CE mark on a product. This still leaves a lot of room for judgment. For instance, an open-frame power supply can't be evaluated to all of the requirements in the revised directive, but can it be CE marked under the new directive? Apparently this is the intention, but the wording is far from clear. For guidance on the marking of component power supplies under the current LVD, see http://www.puls.co.uk/otherPdfs/CE guidance.pdf.

• Certain equipment and components are excluded from the scope of the proposed LVD: This includes equipment intended for human and veterinary medical purposes, components specifically designed for incorporation into goods and passenger lifts, domestic plugs and sockets outlets for connection to an ac mains supply, equipment covered by the Machinery Directive, and equipment covered by more-specific legislation or directives.

• Products intended to be used in conjunction with electrical equipment and designed to contribute to its safe functioning (including cable management systems) are deemed to be electrical equipment for the purposes of the new directive. This type of product could be interpreted as a component that can't be fully evaluated unless it is installed. However, the revisions imply that they are covered.

• Any electrical equipment designed for use with a supply or output voltage not exceeding 1000 V ac or 1500 V dc and intended for the purposes of generation, conversion, transmission, distribution, or utilization of electricity is considered to be within the scope of the new directive. It is important to note, however, that the lower voltage limit is now 0 V, and there are exclusions with respect to some types of equipment.

The current LVD does not state specifically requirements that must be met, whereas the proposed new directive is very specific. This requirement may cause some significant issues for components because manufacturers must comply with all of the requirements or do a risk assessment.

Design Requirements

The new directive lists a number of requirements that must be considered regarding design and construction.

Protection Against Electric Shock and Other Electrical Hazards. Equipment must be designed and manufactured in such a way that persons or domestic animals must be protected under normal or single-fault conditions against danger of excessive current passing through the body. In particular, this protection applies to hazards arising from leakage current, energy supply, electrostatic charges, and arcs. The protective measures must take into account electrical, mechanical, chemical, and physical stresses.

Protection Against Fire Hazards. Equipment must provide an adequate level of fire resistance to an external ignition source and must not contribute significantly to the spread of fire.

Protection Against Mechanical Hazards. Equipment must provide adequate protection against mechanical hazards; in particular, it must prevent hazards arising from instability, ejected objects, rough surfaces, sharp edges or corners, moving parts, and vibration.

Protection Against Other Hazards. Equipment must provide adequate protection against hazards arising from explosion caused either by the equipment itself or by substances that may be produced, emitted, or used by the equipment. Such hazards include implosion, acoustic noise, and excessive temperature of materials ejected. It also encompasses accessible nonworking surfaces, biological and chemical phenomena, and hygiene conditions for equipment intended to come into contact with the human body or with products or substances to be ingested by or administered to human beings.

Other hazards include emissions, production or use of hazardous substances (e.g., gases, liquids, dusts, mists, vapor), and aging of materials. Unattended operation, connection to and interruption from the power supply, and combination of equipment are also covered under "other hazards." If equipment is intended for use in combination with other equipment, each piece of equipment must be designed so that it is possible to combine the equipment without creating hazards (instructions must be provided).

Protection Against Hazards Arising from Incorrect Functioning. Equipment must be designed and manufactured so that it provides adequate protection against hazards arising from malfunctioning due to expected environmental conditions. These conditions include electric, magnetic, and electromagnetic disturbances; logic errors in hardware or software, interruptions or normally expected fluctuations in the power supply; unexpected starting or stopping operation; and failure to stop.

Protection Against Hazards Arising from Electric, Magnetic, and Electromagnetic Fields, and Other Ionizing and Nonionizing Radiation. Equipment must be designed and manufactured in such a way that electric, magnetic, and electromagnetic fields and other nonionizing radiation generated by the equipment is limited to the extent necessary for its operation. It must also operate at a safe level in compliance with the generally acknowledged state of the art, taking account of specific community measures.

Equipment must be designed and manufactured in such a way that any emission of ionizing radiation is limited to the extent necessary for its operation and that the effects on exposed persons are nonexistent or reduced to nondangerous levels.

Ergonomics

Under the new directive, equipment must be designed and manufactured in accordance with ergonomic principles, including the ability to be moved and handled safely.

These requirements are completely different from the requirements covered in most safety standards. The new directive specifically states that the manufacturer of equipment is under an obligation to perform a risk assessment that addresses all of the essential health and safety requirements.

One way to fulfill the obligation of performing a risk assessment is to apply a harmonized standard covering all relevant essential health and safety requirements.

The present practice is to choose an appropriate standard, such as IEC 60950 (used for IT equipment). It is assumed that if the product meets all of the requirements in the standard that it is in compliance with the directive. This is not so with the new directive. The existing LVD harmonized standards will need to be extensively revised to address all of the stated risks, or the manufacturer will need to do a risk assessment. If industry opts to change the standards, it will be a long time before all of them are fully harmonized with this proposed new directive. This means that most manufacturers will need to do a risk assessment, something that is not required for the present LVD.

There is a note in the proposal that a simple procedure for benign products will be discussed and proposed for inclusion in the new directive. This procedure would likely exempt products, such as small calculators and wristwatches, powered by small batteries.

The new directive expands the marking and documentation requirements, but the impact is likely to be insignificant because these requirements are essentially the same as those being required by most agencies. The requirements for a properly completed Declaration of Conformity, while not explicitly stated as such, are now in the new directive.

Equipment must be identified either by means of type, batch, serial number, or any other information allowing for the identification of the product and for the traceability of the manufacturer. The name and address of the manufacturer (and, if the manufacturer is not established in the European Community, the name and address of the person established in the community responsible for placing the equipment on the market) must be included along with instructions for safe installation, maintenance, cleaning, operation, and storage.

Where risks remain despite all the measures adopted or in the case of potential risks that are not evident, appropriate warnings must be provided. The essential characteristics–the recognition and observance of which ensures that equipment is used safely and in applications for which it was intended and for which it can reasonably be foreseen–must be marked legibly and indelibly on the equipment. If this is not possible, this information must be included in the accompanying instruction for use. And, the information–whether provided by marking or in the instructions–must be easily understandable for the intended user. This usually means it should be written in the user's language.

Conclusion

The changes being proposed are major, and discussions with some of the approval agencies suggest that these agencies are not adequately addressing the effect such changes will have on manufacturers or themselves.

Of primary importance is the number of additional products that will be brought under the umbrella of the new directive simply because the lower voltage limit is 0 V! Battery-powered products, including such items as handheld calculators, will be required to comply, and they will potentially need a risk assessment or compliance to a harmonized standard.

In addition, significant changes to the safety standards will be required to harmonize them to this new directive. The industry is in for some real pain. As is often the case, many companies will leave the assessment of the impact until near the mandatory compliance date. They will lack the resources required to accomplish the changes and to evaluate them for compliance with the newly harmonized standards.

Another consideration is the global effect of such extensive changes. Because standards are moving toward worldwide harmonization, perhaps it would dictate that that North American standards will also have to be revised. There has been a push to use CE mark or an equivalent scheme in the United States this directive might have an unintended impact.

It is important to remember that this directive is still in the proposal stage and is subject to lots of change before becoming law. The direction is very clear: compliance with the requirements is going to be a greater challenge in the future.

Resources

Proposed LVD changes; Available from Internet: http://europa.eu.int/comm/enterprise/electr_equipment/lv/direct/review.htm.

"Limited Regulatory Impact Assessment," UK Department of Trade and Industry. Available from Internet: http:// www.com-met2005.org.uk/events_lit/newsletters/
DTI_LVD_Report.pdf.
 
Moe Lamothe, P.Eng, is president of M. A. Lamothe & Associates Inc. (Georgetown, ON, Canada). He can be reached at moe@lamothe-approvals.com.