Zener barriers contribute to the intrinsic safety [Ex i] and are installed in safe areas. Their mission is to limit the level of energy that may appear in an electric circuit routed through a potentially explosive area, whatever the connection established upstream of the barrier. A barrier is made up of: - resistors that limit the current - Zener diodes that limit the voltage - fuses that protect the components
When a fault voltage is applied across the input terminals of the barrier, the voltage that may appear in the explosive zone is limited by a Zener diode, which is in turn protected by a fuse. The current is limited to an acceptable value by the resistor. They can be installed in zone 2, thanks to the Ex nA certification in an IP 54 housing.
Zener barrier for analogic signals Polyester enclosure / DIN Rail mounting For floating potential wiring 3/4: U0=28V I0=118.37mA P0=828.58mW 2/3: Ua=26.8V Ifm=50mA RL=252.6ohm Number of channels: 1 Screw terminals
ATEX / IECEx informations: INERIS 11ATEX0024X / IECEx INE11.0009X Group II (surface) - category (1) G/D II(1) GD [Ex ia Ga] IIC, IIB or [Ex iaD Da] IIIC II3(1) G Ex nA [ia Ga] IIC T4 Gc Installation in safe zone or zone 2 For equipment installed in zone 0,1,2,20,21,22 See leaflet for a safe use
