The safety relay is connected to the safety circuit using a variety of input devices to signal a hazardous condition, and the load contacts are used to connect to the power/control circuit being switched. It is a requirement that a safety relay must provide a manual reset for the return to the normal state, and if the safety relay has detected a fault, is in a faulted condition, or the power supply has been cycled, it must prevent automatic start-up. This forms the basis of a control reliable circuit. The manual reset derives itself from a latching mechanism, the current drawn on coil 1 in N/O state is maintained in N/C latching contact when the input devices and field devices indicate it is safe to return to the normal state, the coil is then de-energized to change the state of the contacts. This type of safety relay uses a mechanical latching, and the same principles are applied using semiconductor devices in a dual or triple redundancy system. The Best pilz safety relay in Indonesia http://www.pilz.com
A safety relay is a relay with enabling circuits designed to be inherently fail-safe. In the event of a detected failure, the safety relay either does not execute any work or it executes a predetermined safe work. Typically, the intended safety function of the system is improved reliability and/or reduced likelihood of damage to a system in the event of a failure. This is achieved by the use of redundant relays or equivalent methods to achieve the safety integrity level. Safety relays are also used to allow machine control for some types of work such as maintenance or setup. In these cases, the unsafe control function can be put off until a safer time, and the safety relay used to initiate the action. Safety relays have become an essential part of safety-related control systems, used as a means to an end regarding hazard analysis and risk reduction. The Best pilz safety relay in Indonesia