Safety Relays. Also called “All–or–Nothing Relays with Positively Driven Contacts”. Relays of this type have contacts that are mechanically connected together, such that if a normally open (NO) or make contact remains closed, a normally closed (NC) or break contact can not re–close. A safety relay detects wire breaks and faulty contactors/actuators by sending out electrical pulses through the wiring. By measuring the flow of current, the safety relay checks for welded contact sets and wire breaks.
Safety relays are used to reduce risk: when a fault occurs and when detection zones are violated, they initiate a safe, reliable response. Relays are the switches that aim at closing and opening the circuits electronically as well as electromechanically. It controls the opening and closing of the circuit contacts of an electronic circuit. A relay contains a coil, an armature, and at least one pair of contacts. Current flows through the coil, which functions as an electromagnet and generates a magnetic field. This pulls the armature, which is often shaped as a pivoting bracket that closes (or opens) the contacts.
Safety Relays are devices that implement safety functions. In the event of a hazard, a safety relay must work to reduce risk to an acceptable level. The safety relay must initiate a safe and reliable response as well as monitor the integrity of its function. Depending on the operating principle and structural features relays are of different types such as electromagnetic relays, thermal relays, power varied relays, multi-dimensional relays, and so on, with varied ratings, sizes, and applications
