Relay and Optocoupler Applications

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Interesting Information and Applications

Control Relay for Ex Applications

Fast and flexible: Relays from WAGO are suitable for use in Zone 2 explosive atmospheres and thus cover a wide range of applications.

Hazardous Areas

Hazardous areas arise in various applications including the chemical industry, during the production of crude oil or natural gas and in the food industry. These are divided into Zones 0, 1 and 2 according to the frequency and duration of occurrence of potentially explosive atmospheres. WAGO relays are suitable for use in Zone 2 explosive atmospheres. For devices that may be used in hazardous areas, labeling is mandatory.

Relays with Ex Approval (Zone 2)

In order to reduce costs but still be able to install the products in the Ex area, facility operators try to use devices with Zone 2 approval.

A type examination certificate or manufacturer’s declaration is required for use in hazardous areas. You can download these from the eShop and add them to your system documentation.

Zone 2

Area in which it is not anticipated during normal operation that a potentially explosive atmosphere will occur as a mixture of flammable materials in the form of gas, vapor or mist with air. If one does occur, then only momentarily.

Relays with Ex Approval (Zone 2)

Control Relay for Systems with Long Cables

Reliable switching despite coupling: To switch on, relay modules require nominal voltage UN. For operation, however, a holding voltage that’s just 15 % of the nominal voltage is sufficient. In standard circuits, all relay modules operate reliably. However, in circuits with long parallel lines, or those with either active two-wire sensors or digital AC control outputs, a low holding voltage often leads to malfunction. The modules no longer switch off.