【 Weak current College 】 on safety barrier of two---Power By 【 China power house network 】

Safety barrier is guaranteed safe automatically control system has a key instrument of spark performance. It installs in the control room, on the one hand; on the other hand control signal transmitted into dangerous places of energy in the explosive gas or mixture of ignition energy following to ensure system security spark performance. At work, I often find someone on safety barrier exists of the error:

I. safety barrier to lightning protection

First, whether the input-or output-type, the safe bar were installed in the control room, so if outdoor cable or onsite transducer lightning, field instrument must be lightning; Secondly, the lightning current up to dozens or even hundreds of thousands, energy giant, can easily be striking and crossed the safety barrier continue to regulate and control instrument. Therefore, whether in the field instrument or control room instrumentation, for Lightning hazards safety barrier are not protected.

Second, install safety barrier after the system has intrinsic safety performance

Intrinsically safe explosion-proof performance is a systemic concepts, i.s. circuit requirements in hazardous areas, such as the transmitter, electric control valves, etc. must be intrinsic safety devices; to an intrinsically safe circuit of the performance of non-hazardous device, also called performance with intrinsic safety; safety barrier to prevent the risk of explosion is enough to produce energy from non-intrinsic safety loop is passed to the intrinsic safety circuit, the three are indispensable, otherwise you lose the system of safety performance.