Electrical Arc Flash Demonstration

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Recommends Andrew Morton · 2023-08 · Electrical Engineering Stack Exchange · on “Transformer primary input”

Here's a short video showing why you let the provider deal with these things: Electrical Arc Flash Demonstration [this video] .

Cites bobflux · 2017-05 · Electrical Engineering Stack Exchange · on “What actually causes a BOOM after a Short Circuit?”

It's all about pulse power... An AA battery will only put out a few amps, so that's only a few watts. A 12V car battery with an internal resistance of 0.005 ohm... (it must have very low internal resistance to put out a huge amount of current to crank your car in the cold winter)... well you're looking at 2400 amps short circuit current, needless to say this is quite a bit of power... Same for a big capacitor at the output of a power supply: a 50 mOhm cap charged to 30V will output tons of power into a low-impedance load. Now, if your short circuit is exactly 0 ohm, then it won't dissipate any power, so nothing will blow. In theory. But in reality, the bit of metal that shorts the battery or

Cites Steve · 2018-07 · Home Improvement Stack Exchange · on “AC: Powering a 25 amp appliance from 2x20 amp breakers”

"lots of sparks to fly" is an understatement. You may have an enormous amount of current available at that location, and a line-to-line short will unleash an ungodly amount of energy which can easily be deadly - arc flash [this video]

Cites Jtl · 2019-02 · Electrical Engineering Stack Exchange · on “Overheating/insulation destruction of Transformers”

In your experience, how many ampere before any two nearby terminals in a home panel can develop into arc flash.. like in this video [this video] and can AFCI totally prevent it or just make the intensity lesser?

Cites Jtl · 2019-02 · Home Improvement Stack Exchange · on “What to put in 60A GFCI breakers in Subpanel?”

My God, I just watched this video of what arc flash can do.. [this video] I thought when you mentioned arc flash. It's just tiny millimeter arc and flash. But it looks like a grenade going off. I'll get back to your shutter (large junction box) plan as priority as I now realized a wooden cabinet is useless. It's scary. Had I seen the video last year, I couldn't have done any GFCI breaker addition. Also now i'm appreciating what AFCI can do. Is there a 100A AFCI that can I put before the main panel so it can protect everything? I don't want separate 6 pc AFCI

Cites Harper - Reinstate Monica · 2019-06 · Home Improvement Stack Exchange · on “Wiring three light fixtures to a headboard for my bed”

Photos would help. Be logged in with the same username or cookie, and [edit] your post and hit the "mountains and sun" icon above the text area. ...... ....... also... keep in mind *mains* electricity is very different stuff than low voltage DC. So Arduinos and LED strips will not prepare you for the destructive ferocity [this video] of a mistake in mains power.

Cites Stack Exchange Broke The Law · 2019-12 · Electrical Engineering Stack Exchange · on “Why shouldn't two AC sources be connected in parallel?”

Note: I am not trained in electrical safety. Do not rely on this post for safety advice. I know you are asking theoretically, but I feel like I should put this disclaimer here anyway. Is it because the waves may not be synchronized and could then cancel out each other? Or something else? That is the main reason, but the consequences are worse than just having the voltage cancel out. Let's imagine the worst case where the sources are perfectly unsynchronized (180 degrees apart - opposite voltages all the time) and that the voltage is at the maximum when you make the connection. Remember that AC is just time-varying DC - at the instant when you connect them together, you have this circuit: sim

Cites Harper - Reinstate Monica · 2021-01 · Home Improvement Stack Exchange · on “Disconnect electrical panel - Can arc occur at 400V?”

You need to de-energize the wiring I realize you're very cocksure, but... Really, really, you need to de-energize the wiring using the normal methods for doing that in your country. Absolutely no one on this forum is going to counsel you to do that work "live", even with the much more docile American 120V-to-ground (2 or 3 phases). Here are the real facts about arc flash. [LINK] [this video] I recognize this panel as being a common American industrial 480V board. (277V per leg). In America this is considered "industrial-scary" and is treated with grave respect. However your voltage is only 18% less than this. You may say "But that's so much more current than I deal with" - nope, when you do stuff

Cites Harper - Reinstate Monica · 2021-02 · Home Improvement Stack Exchange · on “Is the advice "don't operate light switches barefoot" outdated?”

It's relevant to older housing stock, especially where circuits which were ungrounded were extended with grounded wire and that ground was hooked up. This can create an "island of grounds" in the addition area, in which all the addition grounds are connected to each other , but not connected back to the panel. In this scenario, current leakage from any connected device will not be neutralized, because there is no path from ground back to the panel. Instead, all the grounds in the connected "island of grounds" will be floated up toward line voltage! And yeah, you could get nailed by the switch plate cover screws. The risk expands here because all it takes is for any device in the island to ha

Cites Harper - Reinstate Monica · 2021-02 · Home Improvement Stack Exchange · on “Main fuse gets too warm”

By the way, you know America uses lower voltages. We actually do use voltages comparable to yours (277V/480V) in *industrial installations*, and we're strongly warned about the dangers of arc flash [this video] . (the equipment in the video is run-of-the-mill 277V equipment). Your power is only 20% lower than our industrial stuff... so treat it with respect!