These isolators provide 3-way isolation to separate input, output, and power circuits. They are the safest choice when retrofitting or expanding systems where instrument isolation or the grounding schemes are unknown. These 3-way isolators source current out and do not utilize a separate output power supply. The outputs are designed to drive purely resistive loads. The isolator can be located several or hundreds of feet away from the PLC/DCS and obtain power from an external AC or DC source. This source may have a different ground potential than the PLC/DCS or field device. In this case, the power ground must be isolated from both the input and output. Across long distances, the ground potential at a sensor is likely different from the power source and PLC/DCS. Consequently, input to output isolation is also necessary. Additionally, these units can isolate 4-20mA control outputs from the PLC/DCS to field actuators. In the case of analog outputs, the PLC/DCS output is wired to the isolator input and the isolator output is wired to the field device/actuator.

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    330i: DC-Powered Isolator

    • 4 to 20mA DC input
    • 4 to 20mA DC output
    • 10-36V DC power
    • Three-way isolation
    Series 330i isolators provide 3-way isolation and do not require re-calibration for different loads. They accept a 4 to 20mA process current input and provide a 3-way isolated process current output signal.
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    430i: AC-Powered Isolator

    • 4 to 20mA DC input
    • 4 to 20mA DC output
    • 115V AC or 230V AC power
    • Three-way isolation
    • Zero and span adjustment enable precise calibration
    Series 430i isolators provide 3-way isolation and do not require re-calibration for different loads. The 430i accepts a 4 to 20mA process current input and provide a 3-way isolated process current output signal.
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