INA282: INA 282 for AC current measurement 220VAC low side

Martin%20Rodriguez51

Part Number: INA282

Hi! I want to measure alternating currents from 5mA to 1A from 220VAC and thought of INA282. I want to use it on low side as in the schematic below, is it possible?

The circuit will be "open" until the triac receives signal, then it "closes" for a 300ms time, then "opens" again. It is a circuit to test a differential circuit breaker.

I will use a microcontroller powered by trasnformer and 5V regulator.

Regards,

Martin

over 4 years ago

0 Javier Contreras4 over 4 years ago

TI__Mastermind 29810 points

Martin,

You have to look at the neutral voltage vs the GND of the INA282. If this exceeds Absolute max voltage rating then you cannot do this.

0 kai klaas69 over 4 years ago

Guru 140200 points

Hi Martin,

1A x 6800R = 6800V?

Hhm, what you plan to do is a bit dangerous! Can you add to the schematic where exaxtly you want to connect the GND of your 5V supply voltage?

Also, can you guarantee that the pin "Neutral" is always connected to "Neutral"? If not, you could unintentionally touch the "HOT" line...

Kai

0 Martin%20Rodriguez51 over 4 years ago in reply to Javier Contreras4

Intellectual 375 points

Sounds logical!

Thanks!!!

0 Martin%20Rodriguez51 over 4 years ago in reply to kai klaas69

Intellectual 375 points

Kai, on the the schematic current should be around 30mA= 200V/6801Ohm. I did mention 5mA to 1A, but the current changes with the resistor I choose via a rotary switch with different resistors.

GND is floating on my circuit. Based on Javier Contrera´s answer I will search for another solution like an isolated OA or a current transformer, I don´t want to link my GND with neutral from the wall socket.

Thanks

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INA282: INA 282 for AC current measurement 220VAC low side