Welcome back.
Now this is a subject.
That I find very interesting.
Because it is literally a part of almost everybody's modern day life.
Usually in silence.
Many of us have seen circuit breakers.
In our house or business.
More than likely because a circuit breaker tripped.
Circuit breakers.
Are safety devices.
That interrupt flow of a current to a circuit.
If there is either.
A gradual increase in load.
Or a short circuit.
Which trips the breaker instantly.
The most common times for a breaker to trip.
Is when either cooking.
Or for most girls when blow-drying their hair.
I have even heard some girls say.
They are scared to use the blow dryer.
Because it trips the breaker.
And they think it's going to cause a fire.
But the whole purpose of a circuit breaker.
Is to prevent a fire from happening in the first place.
So we know they trip.
But what happens inside the circuit breaker when it trips.
That's what I'm trying to figure out.
So in this episode I'm going to replicate two types of faults.
The first one is going to be a Slow blow or an overload.
And the second one is going to be a complete Short Circuit.
My idea behind this.
Is to show people how the circuit breaker works.
In a way that everybody can understand.
Inside of the circuit breaker we find a couple of key components.
The actuator mechanism.
Contacts.
The terminals were we make the wire connections.
Thermal magnetic strip.
And last but not least.
the lever that we use to turn the circuit breaker on or off.
And reset it in case it trips.
All right ready to go.
I'm just going to straighten this out a little bit.
And I'm going to be careful.
Because that is now live.
Okay let's go.
We now have too many appliances running on one Outlet.
Which is created a situation where the current draw. of the appliances.
Exceeds the amperage rating of the circuit breaker.
This over current condition.
Heats up the bimetallic element.
changing its shape.
To the point where it releases the lever.
Trips the circuit breaker.
And interrupts our circuit.
Let's watch that again.
Well that was really interesting.
Our circuit breaker just came apart somehow.
Instinctively I don't feel safe touching all this but.
I double-checked and it's unplugged.
What I'm going to do now is I'm just going to try to put this back together.
It looks like the spring is what holds all these components together.
This spring has to be like a 5lb spring.
It's hurting my fingers just to put it in place.
Hear that click.
That is a lot of tension.
Alright this is going to be our last Slow blow before our Short Circuit.
Brenda hit it.
I'm doing it now.
Alright so that look pretty good.
As you can see our circuit breaker is now tripped.
And that's what it looks like when a circuit breaker trips.
So I'm going to reset this breaker.
Let's take a look and see what it looks like when you reset it.
To reset a tripped breaker.
A lot of people get confused with this.
You first have to turn it off.
You can see what the lever is doing inside.
And then you turn it on.
Now our circuit is closed.
And we're ready for a next take.
Next thing I'm going to do.
Is I'm going to replicate a short circuit.
A complete Short Circuit.
I know it's going to seem crazy.
But I'm going to do it really simple.
I'm just going to get two wires.
And touch them together.
Which is going to be a realistic replication of a short circuit.
And see what the breaker does.
First thing I'm going to do is.
Get my welding mask.
And my gloves for safety.
Oh yeah baby.
Our dollar store extension cord.
I'm going to unplug our appliances.
And plug-in our extension cord.
Alright here we go.
Short circuit condition.
In 3 2 1.
Now in a short circuit condition this breaker does something pretty amazing.
There is so much current passing through that strip.
It creates a strong magnetic field.
That pulls that lever open almost instantly.
I found it mind-boggling how fast this actually happens.
And if we look at the image data.
We can see that the entire event.
Took a mer 6 milliseconds.
After watching the overload.
And the short circuit scenarios.
The one thing I notice is.
That this particular breaker.
Which is the most common household type.
Seems to be thermal magnetic.
What that means is they have combined two mechanisms in one.
A thermal overload.
For gradual over current situations.
And a magnetic device for situations that need to be interrupted immediately.
Oh I just almost touched that.
Short circuit number 2.
Here it goes.
Well there you go.
Hopefully I warped your perception on circuit breakers.
Next time you have a circuit breaker trip.
Now you know what's happening inside.
And that's about it.
That's how I circuit breaker works.
Thanks for watching.
I hope you enjoyed this episode.
And don't forget to leave any opinions or suggestions in the comment section below.
You can hold all the complaints.
Until next time asta mais.