PILZ safety relay 774350

PILZ safety relay 774350

PILZ safety relay is composed of several relays and circuits combined in order to complement each other's abnormal defects and achieve the complete function of correct and low misoperation of the relay, so that the lower the error and failure values, the higher the safety factor.
PILZ safety relay is composed of several relays and circuits combined to complement each other's abnormal defects and achieve the complete function of correct and low misoperation of the relay, so that the lower the error and failure value, the higher the safety factor. Therefore, multiple safety relays need to be designed to protect different levels of machinery, with the main goal of protecting mechanical operators exposed to different levels of danger.
Safety Circuit Requirements for PILZ Safety Relays
1. When the emergency stop is released, the machine cannot suddenly restart
2. In case of a malfunction in the safety circuit of the machine, the power supply of the machine can be stopped
3. When the safety circuit malfunctions, the machine cannot be restarted
How can safety circuits be achieved if inputs such as safety switches and light curtains that confirm safety cannot achieve the above functions? Is a dual circuit sufficient?
A: Relying solely on dualization is not enough.
Dualization is necessary, but in addition, there are several conditions to consider, such as mutual inspection of the doubled circuit, confirmation that all safety circuits have been disconnected once, and if necessary, it can be started by the operator. From another perspective, when there is a possibility of grounding caused by a short circuit in the input switch wiring or damage to the wire sheath, it is necessary to prevent sudden machine start-up caused by this.
In fact, in order to facilitate the composition of safety circuits, products that combine safety relays with other components and form basic emergency stop circuits and safety circuits into circuit modules are called safety relay modules.
Reasons for using PILZ safety relay
Why can't ordinary relays be used for safety related applications?
Ordinary relays use the mechanical action of coils and metal contacts to switch loads. Metal contacts may melt due to repeated operation. Once this situation occurs, the machine will continue to operate after the operator presses the E-STOP button. At this point, place the user in a hazardous environment. Many European safety standards, the United States, and national standards prohibit the use of simple relays and contactors on machines that pose a danger. In 1987, Pilz invented the DI compact safety relay PNOZ. Subsequently, derivative products such as emergency stops, safety doors, dual hand controls, and light barriers were invented and continuously expanded. Nowadays, Pilz's PNOZ series has become synonymous with safety relays, providing a range of high-quality safety relays such as PNOZ sigma, PNOZ X, PNOZmulti, etc. that meet different application needs.
Configurable safety relays (configurable safety controllers, programmable safety relays)
When there are more than 3 or 4 safety functions, using multiple safety relays will have a higher cost and cumbersome wiring. Faced with the application of multiple safety functions, Pilz has specifically developed a configurable safety relay PNOZmulti.
PNOZmulti is a multifunctional, freely configurable modular security system. Unlike other PNOZ safety relays, the safety circuit of PNOZmulti can be easily generated on a PC using a graphical configuration tool. PNOZmulti is equivalent to a small safety PLC that meets the PL highest safety level of EN 13849-1. Up to 14 different security functions can be used within the basic unit. Expandable input/output module and communication module.

PILZ safety relay 774350