AC versus DC load breaking comparison with a knife switch

Difference in electrical contact by alternating current to direct current. The four resistors are wire chrome 650x4 = 2600 watts.
Note: The voltage of 220V rectified is about 311V, but under load it drops to approximately 213-209 volts.

[redsquirrelftw]

Woah that's a cool experiment, I knew DC arcs were worse but I did not realize the extent. This is why higher voltage DC breakers/switches/relays are so much harder to find and typically more expensive too.

[eudaimonia]

Breakers for DC current are specially designed to interrupt the arc internally. Great demonstration for a benefit of AC power, the waveform crosses 0V, fifty times per second, which clears the arc.

[TheBlairHouseProject]

Wow... excellent demo on why I won't be using an AC relay for my battery bank

[viewer]

thanks a lot - very informative demonstration; now i know that I must be VERY cautious with my 100V+x DC solar panels ;-)

[a]

This is important, so many is now constructing 24v and 48V DC systems with 200 - 400A and more using switches and breakers meant for AC at the AC rated limits not knowing they are creating a fire hazard...

[isso]

This video learned me why you don’t use ac relays for dc applications.

[nid]

now I clearly understood why AC switches clearly marks '230v AC only' I always wondered

[AAAyyyGGG]

Nice setup and probably the best demo of the difference between AC and DC I've seen (30 or so years in Electronics!) Thanks!

[MadsonCCarvalho]

finally, i found this video again. Thanks for share this incredible demonstration

[NotSoCrazyNinja]

One of the many reasons AC won out and DC was not used for home electricity.

[AintBigAintClever]

This video deserves a lot more views, it's a really excellent demonstration, anyone thinking of using AC breakers on DC should watch this.

[BustedMyth]

As always your video's are simple, to the point and highly enjoyable for the thinking person

[TradeWorks_Construction]

An extremely simple and effective demonstration for DC Currents tendency to continue flowing by jumping the air gap when suddenly disconnected.

This makes it clear why you need specially designed breakers that employ an extinguishing chamber to handle the subsequent electrical arc when the contacts suddenly separate from a trip event.

Love the arching! Reminds me of my childhood and some of my first electrocutions... :D

[RODALCO]

Excellent video. Great demo of showing why DC current is so hard to break. and the extra heat in the heating elements.

[realvanman]

With those capacitors across the DC line, the resulting voltage was considerably higher than the AC voltage, as seen in how much more quickly the elements heated up. Still, a very good demonstration.

[Mrtt]

This verifies an experience I observed. The problem was that it was no accident.  
I was watching my mechnic work on my car. He grounded a wire that seemed to explode and started a fire. 
He should have known better that is why I say it was no accident.  
But it impressed me and most likely saved me from doing the same thing now that I am learning about wiring 
up to use PV Solar Power. 
This video speaks loudly about safety issues and training needed by anyone using electricity,
and especially high voltage DC Current.
I want to be safe, this is why I happened to find your video. 
Thank You for posting.  

[onlooker]

Great demonstration - as an old electrical/electronics engineer I’ve know about this but have never seen it in real-time only the after effects!

[stevenking]

I'm watching all your videos AGAIN today! They never get boring! Excellent work sir! S

[punkz]

Despite the voltage discrepancy, I think this is a great quick video to showcase AC having a lower tendency to arc. Regardless of voltage, AC crossing zero potential each half cycle is something that can be used to explain why it is used in a home over DC. Also why much higher AC voltages can be used for transmission more safely. HVDC has made inroads in some transmission lines, as there are technically lower losses from the lack of eddy currents (I think), but overall I really appreciate this video. Look forward to a detailed correction of why some hydro plants and other HVDC links exist.