220V safety control using relay module

Hello.
The relay module controls the 220V fluorescent lamp in Arduino.
It has been confirmed that the lamp also operates whenever the relay module is switched on and off.
But I want to put in a fuse holder because I want to control it while preventing overcurrent more safely,
Is it okay to connect the circuit like this??
I'm currently using an Arduino unit3 compatible board.

Below is the code used.

void setup() {
// put your setup code here, to run once:
pinMode(9, OUTPUT);
}

void loop() {
// put your main code here, to run repeatedly:
digitalWrite(9, HIGH);
delay(500);
digitalWrite(9, LOW);
delay(500);

}

Yes.

But usually the fuse goes in line directly after the "hot" side of the power source so power is cut to the relay and the lamp and most of the wiring, if the fuse blows.

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Do you mean that the fuse breaks due to overcurrent, and the power to other parts is cut off?

In this case, if I replace the fuse with a new one, it works well again, right?

If the fuse blows, then your lamp and wiring is 'hot'. Place the fuse is close proximity to the power supply.

20A fuse? Your blue cube relays are only rated a fraction of that. What is your lamp wattage? What relay is being used?
Use a dolid state relay. They are silent, good for zillions of operations, directly interface, and can control much larger loads than those silly "blue cube" relays ever will.

The lamp I'm using now is Osram G15T8, which is 15W. It's my first time designing and building a circuit like this.
I am not familiar with fuses or relay modules that are often used for these tasks.

20A is huge for a 15W lamp. .2A maybe, but not 20!
unnamed-1
You know the Wattage and Voltage, solve for Current! :slight_smile:

1 Like

Oh, I'm trying to control three 220V products with relay modules.

This article is written to verify that the fuse is properly positioned.

https://forum.arduino.cc/t/correct-position-of-fuse-for-overcurrent-control/1144801/3
The total A on that link is 9.43 A. So I think I should use something higher than 10A, so I'm thinking of 15A or 20A !!

Any fuse higher than 10 amps is no protection at all! You are trying to prevent things getting hot an smoking, so you want protection a few percent above the maximum current. AND you want a fast blow fuse unless you have included an inductive device like a transformer, then you want a slow-blow fuse.
Spend some consideration on the holder for your fuse. IT must be rated for your fuse current or more.

You're not making much sense. 15W lamp, 220V, three of, 9.43A makes me think a mathematical error has been committed.
At this point, produce a coherent schematic showing your intended connections and loads, please.

2 Likes

Flashing a fluorescent lamp every second will destroy the lamp very quickly. It takes longer than half a second for the lamp to start. LED lamps made for household lighting will probably not do much better. They are just not intended for such use.

My recommendation is to stay away from mains voltage entirely until you have learned a lot more about electricity. It is nothing to play with without proper knowledge. The life you save may be your own.

I have also flagged your other post for crossposting. You should run through the tutorial on using this forum and read the rules.

2 Likes

We are trying to use relay module 4 channels to control 220V with Arduino.
I'm trying to install a fuse as a safety device to prevent an accident when an overcurrent is flowing, is this the right position?
The picture below is before placing the fuse.

I'm trying to plug a fuse in here, but I've only used Arduino with mcu, so I know what the fuse does, but I'm not sure where to put it.

I wonder if it's okay to connect and use it like this. Or is there any other way to prevent overcurrent other than fuse??

The fuse is disconnected due to overcurrent, so it is okay to disconnect the power of the relay, 220V product, and other wiring

shorting three outputs is not ok. is it not obvious that each line needs own protection?

No, use a separate fuse for each 220V line.

WORKING WITH HIGH VOLTAGE IS DANGEROUS PLEASE PROCEED WITH CARE OR GET A SPECAILIST.

Use approved devices, what you are showing is a suicide machine. My recommendation is to NOT do this as you do not appear to be qualified or trained to work with these voltages. If you make a mistake it could be the only one you will ever make.

2 Likes

No!!

Solderless breadboards are certainly not suitable for 220V wiring of any sort - let alone at 15A!!
:scream: :scream: :scream: :scream: :scream: :scream: :scream: :scream:

Absolutely!

image

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have to protect the line, have to take additional protections, right?

Oh! Thank you You mean we need to add a fuse for each line.
I'm sorry, this is my first time working in this field as well, and I have little professional knowledge of what parts to use and how to place them.

  • the purpose of a fuse is to protect the cable.
  • the optimum location of the fuse is as close to the power source as possible. you will note that auto fuse boxes are under the hood with the battery, not in the trunk
  • the microcontroller should never be the power source. if you run current through the microcontroller it becomes an expensive fuse.
  • in your circuit the breadboard will be a fuse