The HD5546 accepts a 4/20mA signal from a controller located in the safe area to drive a current/pressure converter (or any other load up to 750Ω) in the hazardous area. It permits bi-directional transmission of HART signals to and from an operator station or hand-held communicator. A line fault detection facility is also provided.Process controllers with a readback facility can detect open circuits in the field wiring: if these occur, the current taken into the terminals drops to a preset level.
Number of channels 1 Location of I/P converters Zone0, IIC, T4-T6 hazardous area Div 1, Group A, hazardous location Working range 4 to 20mA Maximum load resistance 750Ω (15V at 20mA) Output resistance > 1MΩ Over range capability Over range = 24mA (load ≤ 520Ω) Transfer accuracy Better than 16μA Temperature drift Better than 1μA/℃ Input characteristics < 2mA with the field wiring open circuit
Response time Settles within 200μA of final value within 10ms Communications supported Bi-directional HART communications Power supply (20~35)VDC Max current consumption 35mA at 24VDC (with 20mA signals into 250Ω load) Isolation 250V AC/DC between safe and hazardous area circuits NEPSI max approval parameters Terminals 3-4 : Uo=28V, Io=93mA, Co=0.083μF, Lo=4.2mH, Po=660mW LED indicators PWR:green for power on indication LFD:red for open circuit or output overload indication