GfG Double Safety Barrier Two Channel for IR 29 is a transmitter supply module. Use of the SB1 Safety Barrier allows IR 29 transmitters to be installed in Ex Zone 0 Hazardous Locations. Used when limit values for voltage and current must be observed. Ex-Zone 0 places high demands on gas detection devices. These must not cause the ignition of a flammable atmosphere at any time during normal operation or in the event of faults. The SB1 uses resistors to limit the input voltage from 24 V DV to a maximum output voltage of 21 V DC.
The SB1 safety barrier is installed outside the hazardous area. It transmits 4-20 mA signals between intrinsically safe and non-intrinsically safe circuits. The intrinsically safe circuit originating from the safety barrier is routed to Ex zone 0 and supplies an intrinsically safe transmitter with an operating voltage of maximum 21 V. Depending on the transmitter, it is connected via a 2- or 4-wire cable. The supply module is connected to the controller via a 3-wire cable.