Help with Arduino and SCT-013

Using Arduino Sensors
1

Hi everyone! I'm new here
I think I need help with a project i'm working on.

Basically i need to measure the current of a big 380v AC machine,
I bought a SCT-013-000 (100A version) current sensor and started searching on the web for a tutorial :slightly_smiling_face:

I stumbled on this specific tutorial, i recreated the scheme with the resitors, the burden and the capacitor but, i might be doing something wrong since with that code if I measure something, clamping the sensor around one of the AC wires, the Amperes number doesn't change at all (it's stuck at around 0.5A).

To test this prototype before connecting the real 380v machine I'm using a hair dryer rated 2000w at 220v which should consume about 10A.

I'm trying to figure out this by myself from weeks, but I think I'm definitely stuck :sweat_smile:

This is my schematic done on Fritzing:

Screenshot 2024-01-04 132221
Screenshot 2024-01-04 1322211134×1203 101 KB

And this is my code:

#include "EmonLib.h"

EnergyMonitor emon1;

void setup() {
  Serial.begin(9600);
  emon1.current(1, 111.1); // A1 pin, 111.1 calibration number (copied from tutorial)
}

void loop() {
  double Irms = emon1.calcIrms(1480);
  Serial.print(Irms);
  Serial.println(" A");
}

If something is wrong/missing in this thread i created, I'm sorry (it's my first time on this forum).
Also if you need more informations just ask.

Thank you very much in advance!

2

It's not a schematic. It's a breadboard wiring diagram. Because it's not a schematic, it's hard to read and understand. So it's hard to spot if there is an error in the wiring.

Fritzing will help you draw a real schematic. Switch to schematic view, organise the components so that wires don't criss-cross as far as possible. Then draw in the wires. Fritzing will help you by drawing dashed lines between components that are connected in the breadboard diagram, so that you don't miss any.

3

Ok, Thank you!
I'll come back later with a proper schematic.

4

I'm back :slight_smile:
I switched to the schema mode in Fritzing and cleaned up a bit the mess of wires.
I think this is what you were asking for.

Screenshot 2024-01-04 142613
Screenshot 2024-01-04 1426132075×1405 126 KB

1 Like
5

measuring three phase current using SCT-013 100amp clamps I found a ESP32-4-Channel-Mains-Current-Sensor useful
saves a lot of work wiring up the DC offset etc etc, e.g.

image
image646×568 74.1 KB

6

If you have both of the hair dryer wires through the clamp, they will cancel each other, you must have only one of the wires through the clamp.

1 Like
7

@zedux03 did say

8

That is a valid alternative i would consider if this is not gonna working with Arduino.
The only problem (i think) with this is that i don't have a Wemos ESP32 (the one with the short blue board) but normal Espressif ESP32 DevBoards.

Thank you very much anyway!
If i can't work this out, i will try this way :slight_smile:

9

Yes weeks ago i was doing this by mistake, but 'reading the bloody manual' i fixed this.
I made a custom socket so i can plug anything and clamp the sensor on the phase or neutral wire.

10

But he didn't say if the one wire was on the 380V machine or the hair dryer.

1 Like
11

there are different versions of the 4 Channel ESP32 Mains Current Sensor V2
there is a 38-pin Node MCU version

12

just reread the above - if you have a SCT-013-000 (100A version) current sensor it probably already includes the burden resistor - all the 100amp clamp sensors I have do

13

Hmm it makes sense!
I’ll try to remove the burden and read the value again.

14

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