Search

Safety relays are used in safety circuits to prevent dangerous movements. They often complement semiconductor relays perfectly, but in some applications, such as railway and elevator technology, safety relays have clear advantages. Hengstler safety relays are characterized by forcibly guided contacts and fast customer-specific adaptation. They are robust and uncomplicated, generate less power loss than semiconductor relays, and are resistant to voltage and overcurrent spikes. Semiconductor relays, on the other hand, are durable, compact, and offer shorter switching times. Safety and semiconductor relays complement each other perfectly due to their different switching technologies. Semiconductor relays are particularly suitable for applications with high loads, while safety relays protect the semiconductors in case of failure. Semiconductor relays are mainly used in motion and heating controls, while safety relays are preferred in applications with high safety requirements, such as railway and elevator technology. Relays with forcibly guided contacts enable the efficient construction of safety circuits and are used in various applications such as door controls and braking systems of rail vehicles. Safety relays are a meaningful addition to semiconductor relays and contribute to mobility worldwide. [Extracted from the article]

The article discusses a proactive approach to voltage unbalance, focusing on its distinction from voltage variation, the causes and effects and testing for unbalanced voltages and single phasing and prevention before the issue arise. Topics include the effects of voltage unbalance like additional heating, harmonic currents, and single-phasing operations, and ways to correct unbalanced voltages such as redistributing unequal load, derating the motor, and using protective relays.

Lists companies in the United States that manufacture relays. Coaxial cable; Current sensitive; Electromagnetic; Electromechanical; General purpose; Hybrid; Industrial control; Keying and break-in; Latching; Mercury; Overload; Overvoltage and undervoltage; Phase reversal; Power; Reed; Sensitive; Solid-state; Stepping; Subminiature; Thermal; Time delay; Vacuum.

The article reports on the use of gas discharge tubes (GDTs) for optimal protection of broadband digital communication. It cites that GDTs are reliable tools in protecting telecommunications systems and equipment from lightning and power-fault conditions. It explains on how general GDT operates and how it affects telecommunications. GDT disadvantage is that it has inconsistent electrical measurements and these inconsistencies are caused by the contaminants into the gas. The article also provides diagrams depicting the GDT ramp-impulse versus dc-breakdown (DCBD) voltages and GDT's DCBD voltage performance.

The article presents information on gas-discharge protector. Several factors to consider in selecting a coaxial protector are the connector type and operating frequency. The gas discharge tubes connect between the center conductor and outer housing. It suggests the use protectors when coaxial cables are brought into a building or structure from outdoors.

Presents information on several relays and switches used in the machinery industry. Series 520 inductive proximity switches from Contrinex Inc.; FTR-H3 Form A relay from Fujitsu Components America Inc.; Solid-state power-control relays from HBControls Inc.

Discusses the installation of digital protective relays in the Yates Field and Indian Basin Gas Plants of Marathon Oil company in the U.S. Costs of electric power failure at these plants; Problems with the switchgear facilities at the plants; Benefits of the installation of digital protective relays.

The article evaluates the PNOZ-sigma safety relay from Pilz Automation Safety LP.

Introduces two electronic devices. Series 24 replacement lock-out relays from Electroswitch Corp.; Panalarm Series 90A annunciator from Ametek Power Instruments.

Reports that Force Guided Relays International will act as master distributor in North America for Hengstler GmbH. Countries where Hengstler products are distributed; Details of Hengstler force-guided safety relays.

Highlights the development of the E-Stop Safety Relay system from Banner Engineering Corporation used for machinery that must incorporate an emergency-stop circuit. What the Safety Relay's output consists of; Features of the relay system.

Provides information on Entrelec Incorporated's safety relays. Different types of relays available; Features of the relays; What the emergency stop devices includes; Functions of the relays.

Focuses on the benefits of Entrelec Inc.'s monitoring relays for the operations of printing presses from Heidelberg Harris. Prevention of costly downtime and equipment damage; Operating voltages; Ability to shutdown the presses when rollers lack sufficient water.

Focuses on monitoring relays that continuously measure and compare numerous electrical parameters against a preset range. Built-in time delays; Protection of motors in single or three-phase industrial controls; Entrelec Inc.'s monitoring relay.