Ads
related to: safety relay vs normal flow valve sensorPhone support response time less than 45 seconds - Stella service
Search results
Results from the WOW.Com Content Network
The device usually acts as the interface of a sensor (such as a light curtain), designed to signal a safety-related event, typically when the light curtain beam's being "broken". OSSD signals are the outputs from the protective device (light curtain or scanner) to a safety relay. OSSD outputs are typically semiconductor or transistor outputs ...
Safety relays must always be designed in such a way that, if wired correctly, neither a fault in the device nor an external fault caused by the sensor or actuator will lead to the loss of the safety function. [8] A normal relay uses a wire coil and the mechanical movement of the metal contacts to switch the load on and off.
One example of SIS is a temperature sensor that provides a signal to a controller, which compares the sensed process temperature to the desired temperature setpoint and sends a signal to an emergency on-off valve actuator which stops the flow of heating fluid to the process if the process temperature is exceeded by an unsafe margin.
A relay Electromechanical relay principle Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off. A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple ...
After the control of air flow and temperature was standardized, the use of electromechanical relays in ladder logic to switch dampers became standardized. Eventually, the relays became electronic switches, as transistors eventually could handle greater current loads. By 1985, pneumatic controls could no longer compete with this new technology ...
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. [1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure , temperature , and liquid level.
IEC 61508 is an international standard published by the International Electrotechnical Commission (IEC) consisting of methods on how to apply, design, deploy and maintain automatic protection systems called safety-related systems.
It is designed for connecting simple field I/O devices (e.g. binary ON/OFF devices such as actuators, sensors, rotary encoders, analog inputs and outputs, push buttons, and valve position sensors) in discrete manufacturing and process applications using a single two-conductor cable.
Ads
related to: safety relay vs normal flow valve sensorPhone support response time less than 45 seconds - Stella service