Choosing a 3 Phase AC Current Sensor for Motor Monitoring

Hey everyone,

I’m a research assistant at a university, working on a project where I need to measure AC current on a 3-phase cable supplying an electric motor. The measured current data will be sent to a microcontroller. Since I’m a mechanical engineer with limited experience in electronics, I could use some advice on selecting a suitable sensor.

The motor typically runs between 30A and 50A, but during startup, it can spike up to 450A. I’d prefer a sensor with a DC 0-5V or DC 0-4mA output, and ideally, it should run on a 12VDC supply (though this isn’t a strict requirement). I was looking at the ATO-CUS-3AC80 and ATO-CUS-AC1500 but wasn’t sure if they were suitable. Any recommendations?

Hey everyone,

I’m a research assistant at a university, working on a project where I need to measure AC current on a 3-phase cable supplying an electric motor. The measured current data will be sent to a microcontroller. Since I’m a mechanical engineer with limited experience in electronics, I could use some advice on selecting a suitable sensor.

The motor typically runs between 30A and 50A, but during startup, it can spike up to 450A. I’d prefer a sensor with a DC 0-5V or DC 0-4mA output, and ideally, it should run on a 12VDC supply (though this isn’t a strict requirement). I was looking at the ATO-CUS-3AC80 and ATO-CUS-AC1500 but wasn’t sure if they were suitable. Any recommendations?

Hey everyone,

I’m a research assistant at a university, working on a project where I need to measure AC current on a 3-phase cable supplying an electric motor. The measured current data will be sent to a microcontroller. Since I’m a mechanical engineer with limited experience in electronics, I could use some advice on selecting a suitable sensor.

The motor typically runs between 30A and 50A, but during startup, it can spike up to 450A. I’d prefer a sensor with a DC 0-5V or DC 0-4mA output, and ideally, it should run on a 12VDC supply (though this isn’t a strict requirement). I was looking at the ATO-CUS-3AC80 and ATO-CUS-AC1500 but wasn’t sure if they were suitable. Any recommendations?Based on your requirements, I'd recommend the ATO-CUS-3AC80 model. It measures up to 80A with 0.5%FS accuracy, which should work well within your typical range. Let us know if you have any other questions!

Thanks for the insights! That helps a lot. I do have one more question about the "overload capacity" listed in the datasheet. It says "30 times nominal input." Does this mean the sensor can handle up to 2400A for a short time? If so, how long can it withstand that overload?