How to Use a Toroidal AC Current Sensor – 8401044

Using Acromag’s Toroidal AC Current Sensor Model 5020-350

How to Use a Toroidal AC Current Sensor

Transmitters with DC current input can be used in conjunction with an external toroidal AC current sensor in order to precondition an AC current input signal. This sensor is a highly accurate toroidal instrument transformer; which converts an AC current signal to a safe, low-level, DC milliampere signal (0 to 11.17mA).

The transmitters only accept the isolated low-level signal that’s produced by the AC current sensing transformer; they cannot be connected directly to the source of AC power without damage or safety risk. The AC Current Sensor is fully insulated and designed for mounting near the source of the AC current. The input AC current range is a simple function of the number of turns placed on the AC Current Sensor. The benefits to using an external sensor (external from the transmitter) include the following:

Low Losses:

It is not practical to run AC currents over long distances because of significant resistance voltage drops at high currents. The low-level DC milliampere signal output from the AC current sensor can be transmitted safely over long distances; allowing the transmitter to be remotely located from the AC power wiring.

Safety:

The AC Current Sensor’s output leads can be open or short-circuited; these conditions do not affect the AC current loop or cause damage to the sensor. Likewise, the wires that connect the AC current sensor to the transmitter can be removed easily from the transmitter’s input terminals, without concern or hazard.

Ease of Calibration:

AC current input ranges are easily scaled in the field by simply changing the number of primary turns at the sensor. With this process, no additional calibration required. That is, the AC current input span is a simple function of the number of primary turns placed on the AC current sensor; thus sensor/transmitter calibration is not affected.

Supported Products

 

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