I am trying to determine the best option for monitoring the current in a specific application but am having difficulties deciding between a current transformer, Rogowski coil or Hall effect sensor.
The main purpose of the sensor is to determine whether there is any fault or unbalanced loads in the circuit. Under normal operating conditions the current flow will be fairly low in the 0-20 A range. For unbalanced loads the current can go up to 60-70 A. The main concern are jacket faults which can lead to currents up to 400 A for an extended period of time.
The aim of the current sensor is to detect when these currents rise so that action can be taken before any significant damage is done to the cable.
The main concern is accuracy, however there is some leeway there as an issue with the cable will usually cause a fairly significant increase in current.
Another major concern is price.
The current transformer seems like a viable choice since it has a large current range and is fairly accurate. However, while the Rogowski coil is typically used as a method for temporary current measurements, I have also seen that it can be used as a low cost alternative to a CT. From my understanding, many of the issues with accuracy for a Rogowski coil are due to positioning, but this would be installed in a solid box so the coil would always be in the same predetermined position. I do not know if this is enough to achieve a higher accuracy though.
The Hall-effect sensor I do not think makes much sense since we do not need to know DC currents and they are more difficult than CT's to engineer for high accuracy. Also, from what I have seen they tend to be higher cost but they do seem to come in a fairly wide range of prices. I did not want to rule them out altogether at this point.
Thank you for any help or guidance you can offer.