ESR4 safety relay

Safety guaranteed

Moeller offers safety relays of the ESR4 series for example, so that your Emergency-Stop button, safety doors or two hand controls are safely detected and evaluated and perform their respective actions.

All ESR4 relays feature a width of just 22.5 mm. In addition to all approvals of the German employer's liability insurance association and CE marking, these devices are also approved as devices for world markets and include UL and CSA approval.

Safely monitored Emergency-Stop circuits

The electronic safety relays ESR from Moeller switch several enable current paths for direct or time-delayed disconnection of the energy supply when the Emergency-Stop actuator is triggered. Depending on their configuration, they can detect faults such as cross short-circuits, earth faults or short-circuits in the Emergency-Stop actuator circuit. These lead either to immediate disconnection or prevent restart as long as the fault is not remedied. Safety relays for category 4 feature additional restart monitoring. The enable becomes effective only after the On button is released. Tampering is safely avoided in this manner!

The safety relays conform to the demands of categories 2 to 4 of the EN 954-1 depending on their type and configuration.

For applications which require more contacts, the ESR relay can be extended by the expansion module ESR4-NE which each provide up to four additional enable paths.

For processes which must be retracted or wound down and may not be directly de-energized (Stop category 1 to EN 60204-1), there are delayed safety relays ESR 4-NV available. They are suitable for time ranges up to 30 s.

Monitoring mobile protective mechanisms and light barriers

The monitoring of protective screens on machines and processing centres is another important function of the electronic safety relay ESR from Moeller.

Depending on the safety level, one or two position switches signal that the protective door is in the closed position. Instead of restartmonitoring, you can also implement an automatic start with the safety relays. Thus, you reduce the cycle times in production without dispensing with safety.

Safety relays of the series ESR4-NO-30 and ESR4-NO-21 can be used for processing signals from the output switch elements of a light barrier conform to EN 61496-1.

Safe operation with protective equipment: two hand controls

Safety relays On machines which have a high potential for injury, e.g. presses, shearing and punching machines with two hand controls, both of the operator's hands must be located outside the hazardous area before the hazardous machine movement can be initiated.

In order to protect the operating personnel, it is necessary that the two hand control is operated with both hands simultaneously within a time window of 500 ms, in order to operate the machine or to keep the machine in an operational state.

Monitoring of the timing sequence is assumed by the ESR4-NZ-21, which can be used for two hand controls which conform to the safety requirements of category IIIC to EN 574.

This page last updated: 22 September 2007