Intrinsic Safety - System Concept: Safety Barrier, IS field device, and field wiring скачать в хорошем качестве

Intrinsic Safety - System Concept: Safety Barrier, IS field device, and field wiring

An Intrinsic safety system involves three main components: • An intrinsically safe field device • A safety barrier, the energy limiting device • Intrinsically safe field wiring which connects the barrier to the field device Intrinsic safety is a system concept, and it is necessary to consider the safety of each component of the system. The safety barrier limits the maximum amount of voltage, current and power transferring to the field device to safe levels. Under normal operation, the barrier is not needed as a safety device. The input voltage and current from the power source, for example, may be transferred directly to the field device without any changes. If a fault happens on the controller, on the other hand, and 250 volts is delivered to the input terminals of our safety barrier, the output voltage remains the same as the maximum allowable value, in our case is 24 volts for example. Similarly, if a fault happens within our field device located inside the hazardous area, the safety barrier limits this faulted current to the allowable maximum level that can flow into the hazardous location from our controller. For more details, please visit our website: www.hazlocdirectory.com