Products with integrated short-circuit isolators (SCIs) were also fitted. On a healthy addressable fire system, the voltage from the fire control panel is driven one way around the loop, both powering devices and carrying data. But if a fire loop cable is accidentally damaged by tools, equipment or chemicals for example, particularly if not mechanically protected by conduit, and the result of that damage is that the positive and negative conductors within the cable make contact with each other, that vital voltage level drops. This is a short-circuit and at this point this entire loop is instantly out of action, which of course puts the whole building and its occupants at risk.
Hochiki’s SCI-enabled devices recognise this voltage drop and when they activate, they divert the loop voltage back along one of the conductors, maintaining the flow of power and data for the rest of the loop.
At the same time, because it is programmed to recognise when it’s no longer receiving a return loop drive voltage, the fire control panel will automatically switch to driving voltage from both ends of the loop, using both conductors. In high-risk manufacturing environments such as Technical Metals, this innovative technology makes all the difference.