SIC 3625 Relays and Industrial Controls

Contenidos

• NAICS CODE(S).
• INDUSTRY SNAPSHOT.
• ORGANIZATION AND STRUCTURE.
• BACKGROUND AND DEVELOPMENT.
• CURRENT CONDITIONS.
• INDUSTRY LEADERS.
• WORKFORCE.
• RESEARCH AND TECHNOLOGY.
• FURTHER READING.

SIC 3625

This category covers establishments primarily engaged in manufacturing electronic relays and industrial controls used for starting, regulating, stopping, and protecting circuits and electric motors. Mechanical switches and relays are classified elsewhere.

NAICS CODE(S)

335314

Relay and Industrial Control Manufacturing

INDUSTRY SNAPSHOT

The industry encompasses two major categories: electronic relays and industrial controls. Electronic relays are used in circuitry for computers, communications equipment, and a multitude of other electronic devices. A relay is basically a switch that is used to open or close a circuit. It controls the flow of electricity to create a desired result. Most industrial controls essentially are switches, but of a more complex nature. They usually are associated with the control of electric motors and systems. Industrial controls include devices such as motor starters, contactors, control centers, and programmable logic controllers.

A conventional electronic relay contains a solenoid, which is a coil of wire with an enclosed, fixed iron core. When electricity passes through the wire a magnetic field is created that energizes the core. An armature connected to the core allows it to move and activate, or trip, the relay. Smaller relays used in transistorized equipment work similarly but are much smaller and require a fraction of the power consumed by electromechanical relays. The tiny reed relay, for example, is made with two flat magnetic strips. The separated strips are sealed in a capsule filled with an inert gas (to prevent corrosion), which sits inside a coil. When electricity is applied to the coil the two magnetic strips are drawn to each other, thus completing a circuit. Finally, miniaturized solid-state relays are not magnetically activated but are instead triggered by electrical pulses.

Total industry shipments in 2002 were valued at $10.18 billion, down slightly from $10.66 billion in 2001. Employment declined steadily each year between 1998 and 2002, falling nearly 30 percent during the five-year period from 67,885 to 47,866. Revenue losses were attributed primarily to a recessive economy and as the overall economy rebounded during the mid-2000s, the industry began to show positive growth.

ORGANIZATION AND STRUCTURE

Two standards for industrial controls are administered by the International Electrotechnical Commission (IEC) and the National Electrical Manufacturers Association (NEMA). IEC-approved controls conform to standards that have brought them a reputation for compactness and affordability. Controls rated by NEMA, while considered less streamlined, generally are perceived by users to be more reliable and serviceable for heavy industrial uses. Parts, accessories, and miscellaneous related items make up the remaining share of industry products.

The largest consumer of relays and industrial controls is the computer equipment industry, which purchases approximately 15 percent of production. Most of the remaining output was consumed by various manufacturing industries, particularly those producing electrical and electronic equipment. Machine tool producers, for example, make...