Contactor quality is essential to ensure that electrical systems are safe and reliable when using high voltage or power electronics. If you’re in the electrical equipment manufacturing business, or perhaps even the design of those systems, you need to know about contactor quality standards. In this article we’ll go over the key quality standards and specifications of a contactor define it.
What is a Contactor?
A contactor is a relay that has its contacts controlled by an electrical signal. While regular relays may be used to switch power, a contactor is used typically in high volume applications where it is going to be switched frequently on and off, such as industrial machines and motor controls and lighting switches. These switches are designed to handle much more current and voltage, and must be of the highest quality.
Key Contactor Quality Standards
Contactor quality is defined by various standards that ensure consistent performance and safety. Many of these are accepted world wide; find below those you should be aware of:
IEC 60947-4-1 – International Standard for Contactors
This international IEC standard covers contactors and contains global requirements regarding the design, performance and characteristics of contactors used in electrical circuits. The characteristics described in the test standard include: electrical durability, thermal durability, electrical insulation, and insulation.Guidance to contactor manufacturers on characteristics and tests for high voltage and high current is provided in IEEE 730. However, manufacturers of contactors for industrial and commercial applications should have their contactors conform to the tests and criteria specified in JIC, so that their products will suit these applications. 2. UL 508: Standards for Industrial Control Equipment In the United States, UL 508 is the adopted standard for industrial control equipment and contactors. Some topics that the standard covers include: Thermal overload protection Short circuit protection Component integrity Every contactor component, including terminals and the enclosure Thus, for contactor manufacturers wishing to sell into North America, achieving UL508 approval will suggest that their product can be safely used in electrical systems. 3. ISO 9001: Quality Management System Not contactor specific, but ISO9001 is a topical and commonly accepted standards for the quality management system (QMS), which covers the whole of the manufacturing process: -Verifying that the manufacturer has the right processes for assuring the constancy of the quality of the product: -Ensuring that both material control and all other parts of the pro9ess, through to final inspection, meet the necessary quality requirements. -A further implementation of an ISO 9001 standard obliges the company concerned to pay continuing attention to the improvement of product quality.Manufacturers who are serious enough about quality to attain ISO 9001 certification clearly do so “at every level.”
RoHS Compliance: Environmental and Safety Standards
Contactors and their components should be free of lead, mercury, cadmium, and other hazardous substances, as required by RoHS (Restriction of Hazardous Substances) compliance, an important consideration, especially in light of the demand for safe materials and components. RoHS-compliant contactors are safer for both users and the environment and should be specified in projects where required in the market for electrical/electronic products.
For contactor manufacturers, RoHS compliance ensures that products conform to relevant legal requirements in electrical and electronic equipment in the European Community and other geographic areas with similar standards.
ANSI C37.16: American National Standards for Power Switchgear
To support the guide to power switchgear, an equivalent set of standards for contactor switches is set in ANSI standard C37.16, which specifies the following requirements:

• Interrupting Capacity
• Mechanical Strength
• Voltage and Current ratings
  Meeting ANSI C37.16 means that contactors are able to manage high power systems in a safe manner.
  Testing and Certification for Quality Assurance
  Knowing the standards for assuring quality in contactors is great. But how about knowing how they’re tested? Several procedures ensure good quality including:
• Temperature Rise Testing.
• Dielectric strength.
• Endurance Testing.
  Independent testing to agree or documen the following industry standards is/data is conducted by various accredited agencies. Look for a known name in testing.
  Conclusion: Assuring Quality
  When specifying and purchasing contactors, following standards to assure success isn’t “optional,” make sure they’re “on the list,” and work with manufacturers and suppliers who know that they are.