Zener Barrier

Zener BarrierThis is a 2 wire device which can pass an electric signal in either direction but limit the transfer of energy. When connected between equipment installed in a safe area and fire sensors mounted in a hazard area these devises will limit the power entering the Hazard area in the case of a fault condition in the safe area.These barriers have 30v Zener diodes which limit the voltage entering the hazzard area. They are wired in series with a resistor and electronic fuse in each leg. They are polarity  sensitive designed to be used to protect floating supply equipment.Any fault transients bet ween Positive and negative are shunted between the two inputs and transients between an input and earth are shunted to earth. In case the current level rises beyond the safe limit then a fuse will interrupts this current. The Fuse will automatically reset itself when the fault condition no longer exist.  SpecificationsModel: ZB-28-05Hazard Area Side.   Max voltage 28v DC.  Max Current 50mA. Safe Area side.  Max voltage 30v Normal Current 2 mA. Alarm Current 10 mAMax Fault voltage 230v Max Fault current 50 mA. Above ratings are measured between two inputs. Max Voltage from input to earth. Positive or negative 30v.