Nice overview of the 240v US electrical system

[kb0nes]

Ran across this video today. Decent overview of how things work.

This channel has other really well made videos also. He did quite an involved episode on the Toastmaster toaster that is worth a look too.

 

[DADoES]

 
It came up in my feed yesterday and caught my attention but I haven't yet watched it.

 

[launderess]

As one over the years who has dealt with European

Electrical appliances, and how to get them to run on American domestic electrical current, knew much of this already. But it was entertaining one the less, certainly one of the better YT videos have seen lately.

Really is a shame how backwards (yes, I know) American power system is; but nothing will change since things are baked into cake so to speak.

 

[launderess]

This site doesn't have stickies, but someone really should keep this link.

It would prove invaluable to those who bounce into AW asking about wiring or using European appliances in USA. This and the other common enough discussion here; differences between 120v, 208v and 240v (or 220v as some like to say...*LOL*)

Shame this guy doesn't have more subscribers, found him engaging and interesting. Far more so than some of one's professors in college on same subjects.

On another note there are devices sold in USA that exploit uniqueness of our electrical system to get 240v where it doesn't exist.

Quick220 Electrical Systems

120v to 240v voltage converters, international plug adapters, voltage testing equipment, residential Tesla chargers

www.quick220.com

 

[rolls_rapide]

The guy in that video is a blethering arse!

The reason for switches on UK sockets is twofold:

1: to disconnect the live side, rendering the flex and appliance safe. The plug can only be inserted one way, so the live conductor in the appliance and plug is always connected to the live side of the socket, provided the socket and plug have been correctly wired.

2: to provide a means of switching the appliance off should the onboard switch not be present or fail - and more recently, those appliances which are always 'on' such as tellies. I certainly don't trust leaving it plugged in, always on, even when it is supposedly off.

You can still buy unswitched 13amp sockets. These might be used where a dishwasher or front-loading washing machine are installed under a countertop. Typically, a double-pole isolator switch is installed on the wall above the countertop, possibly labelled with the type of appliance, e.g. 'Dishwasher', and with an integral neon lamp.

Oh, and as for sparks from plugs and sockets being safe... This refers to the 2-way or 3-way cube block adapters, but it is still relevant:

"An inspector said the fire began next to her bed, where the adaptor was plugged in and had fallen slightly out of its socket, creating a spark."

Derry Girls' Siobhan McSweeney living out of suitcase after horror house fire

Derry Girls Siobhan McSweeney has been left haunted by a raging house fire that burnt her home down, and is still living out of a suitcase four months later

www.mirror.co.uk

 

[mattl]

It comes down to what you are used to.  I can see no conceivable value to having a switch on a plug, very impractical for me.  I have perhaps 60-70 outlets in my home many behind furniture or some distance away from a lamp or appliance, I'm certainly no going to crawl on the floor or move stuff to switch an outlet on or off. And I'm not going to unplug anything at any point, I plug it in it stays plugged in.  'if I want a switched plug I simply install a wall switch to control that or those outlets.  We can easily switch one half of every duplex outlet if we so choose when initially wiring a home.

 

Any item made in the last 20+ years also has a polarized plug, same as the rest of the world.

 

[combo52]

Reply #5

Hi Matt, good points, I can see almost no value in having switches on outlets, it makes them bigger and more unsightly more completed and expensive and like you I have more than 60 outlets in this house, Switches can overheat and either fail or in rare cases start a fire as well.

 

John L.

 

[gizmo]

Here's why you would have a switch on a power outlet.

When I was a kid we had a Simpson electric stove which had a power outlet on the dashboard. It was unswitched which is extremely unusual here in Australia. Probably a hangover of its American heritage - It was "Simpson by Tappan", so presumably a US Tappan design made in Australia under licence by Simpson.

When I was about 13 I came home from school one day and as I walked in the back door my mother was screaming, I ran in, she was standing at the stove and was obviously getting an electric shock so I ran to the switchboard and flicked off the mains power. When I ran inside Mum showed me that she had been using a hairdryer plugged in to the stove, the cord had touched the (still hot) element on the stove and melted the insulation but she hadn't noticed and grasped the damaged cord to pull out the plug.

we never used that unswitched socket again and the stove was soon replaced. Why use the hairdryer in the kitchen? because our house didn't have a power outlet in the bathroom.

The point is, it is safer to unplug an appliance if the power outlet is no longer live - in case the plug or cord are damaged. Also it means you are less likely to unplug an appliance when it is consuming close to maximum current (for example a heater) which can cause arcing and burning of the pins on the plug if done repeatedly.

When I went to the USA in the 1980s I was amazed that power outlets didn't have a switch. People used to be pretty casual about getting a zap, perhaps 110v isn't as lethal as 240v? I also noticed that many more appliances in the US have a simple single insulated Figure-8 cord with no outer sheath, uncommon here at the time and I believe no longer legal on new appliances here.

 

[panthera]

Being German (not German-American)

I know all about the advantages of 230V single phase.

I thought the video was outstanding. I watch all his work, always great.

I find North American plugs scary.

I find UK plugs outrageously too big.

Given how many North American workshops have a power switch in the same box as the outlet, it's silly to have this discussion. It's not the UK outlets which are the problem, it's their outsize plugs.

Any country which still uses the dangerous ring circuit and those outrageously oversized plugs is in no position to criticize other countries' safety faults (except the Nema 5-15 et al. plugs. Super scary unsafe!).

Yes, North American plugs also can have fuses and many do.

120V 60Hz is pretty damn lethal, thank you very much. 

Oh, and, yes, I wish North America used the same 230V 50Hz system with decent continental polarized plugs, too.

Just, no, never, those UK abominations.

(Oh, and just to add fuel to the flames, split-phase is very much in use in the UK, just go to any outdoor construction site).

 

[rolls_rapide]

Reply #6

What a lot of rubbish!

Reply #7:
Absolutely correct.

 

[combo52]

In an emergency

It is far faster and more instinctive to just pull the plug than groping for a small switch at the outlet maybe even wasting precious turning off the wrong switch if more than one cord is plugged in to the outlet group.

In the accident in reply #7 when you ran in and found your Mother being shocked you should have grabbed the plug and pulled out the plug, I know in hindsight it is easy to see what you should have done.

This is why it is important to teach electrical safety as soon as possible, because you could not have gotten a shock using one hand to pull the plug and your Mom could have died while you were running for the main power switch.

It is no safer to flick a switch than pulling out and insulated plug from a socket in an emergency.

John L.[this post was last edited: 6/25/2020-10:15]

 

[foraloysius]

Great video, explains it very clearly. It's easy to bash other systems, but each system as it's own history, both the USA and UK system. Personally I'm glad with the NE European system (there are variations on it in some countries) with the Schuko outlets and plugs. Since 1996 grounded outlets in every room are mandatory, you don't find ungrounded ones anymore in newly built residences. Combined with a GFI for the whole house except for the washing machine outlet it makes quite a good system.

 

[foraloysius]

More intriguing to me are the differences in breaker panels.

 

[mattl]

Yes, quite a difference in panels.  Mine is basically much like the the one i the video, I have 50ish circuits.  Over the decade I've split off many of the original circuits since I felt they were too big.  I need to split one or two more into two or three circuits, but with the advent of LED lighting the current drain is greatly reduced.   I had one circuit that when entertaining would always trip.  It had 4 100w exterior lights, 15 60w bulbs in the foyer chandelier and 16 60w bulbs in the Dining room chandelier - of course the two lights were on dimmers so that did limit the current drain. It should have never been wired that way but back in the 60's no one planned for that kind of lighting. Originally it was 2 5 light chandeliers, no where near enough light for the large rooms.

 

I will also reiterate a point I've made her several time over the years, it's good practice to replace, or at least inspect every outlet and switch every decade or so. A few years ago I went through and replace every outlet and switch in the house, I was amazed at the issues I discovered.  Loose wires, burned insulation, bad grounds and so on.

 

[panthera]

Matt is so right!

Everytime we paint a room, I change out the switches and outlets, unless they're quite modern GFCI or had just been done - then, I still check them.

Worst offenders - the backwired (I don't mean the quality backwire systems) outlets and light switches. That system just plain doesn't work in the 'States. At.All.

 

[brisnat81]

I watch all his videos too, he does a pretty good job. His series on the CED was pretty interesting too.

I think it comes down to what your used to. Here, we're used to switches and turning them off is simple, the switch is aligned with the socket and its simple. You just dont need to unplug stuff, you just turn it off at the wall.

Its not as easy to just yank out the cords in AU, they have a reasonably good grip and dont just fall out of the socket like they do in the US. Where the cord exits at a 90deg angle to the plug, you have to grip the plug to remove it, you'd need a really violent tug to just yank it out. The Angled blades tend to get it stuck with upwards or downwards pressure.

I do find the wastefulness of the US system offputting. With 240v 20amps the standard here and 10amps (2400watts) available to any plug, it is very rare to find even a large house with more than 10-15 circuits. When you look at all the copper involved in all those home runs back to the panel, it just seems wasteful. Its a lot of material that most other countries just dont need by comparison.

 

[gusherb]

I've been replacing outlets and switches in our house for the last 15 years, every time a room gets repainted. This past February I finished off every room in the house except for the master bedroom and made sure to get all the odds and ends this time. My main motivation for this wasn't because the contacts in the outlets were weak, but because the majority of them were backstabbed and those connections become weak over the years. I like to use Spec grade outlets so I don't expect anything to have to be replaced for 30+ years. I've had a cheap builder grade outlet start burning up right in front of me, with a 10k BTU window AC plugged into it. 

 

I don't think it's particularly wasteful to wire everything for 120V vs 240, but what I don't like is the power limitations on appliances with 120V. If you're looking at the above images, you're comparing Romex (US) to conduit (european setup). That US setup is also in a larger house based on the number of circuits, a typical 1500 Sq Ft ranch would only have about 15-20 circuits and far less Romex spaghetti mess than that. Also, in this area it used to be common up til very recently to use EMT for residential electrical so things looked much cleaner around the panel than that example. 

 

[combo52]

Comparing Main Service Panels

This is the main panel in my primary home, this 200 Amp Square-D panel was installed in 1987 when we almost doubled the house size, it should easily last 60-80 years.

 

I put a 100 Amp breaker in that feeds the homes original 100 Amp Push-Matic panel from the original home construction in 1955, I expect this panel to last over 100 years.

 

Both panels use solid copper buss bars and cases are always steel in the US, generally electrical systems in US homes after WW2 were good enough to last over 100 years with some updating. 

 

The original part of the house is all wired in steel covered BX wiring, when the addition was done in 1987 I did all the wiring in BX as well, almost 3000 feet of it.

 

John L.

 

[mattl]

At some point soon I will be replacing my 2 panels with a new updated single panel. The original 60 amps service was wimpy even by 1965 standards, really not sure why because the custom builder did not skimp, nor did my parents.  I converted to a 200 amp underground service in the late 70's and added a second panel.  The original panel has breakers that have failed and while I can track them down, it's hard.  Really just want to clean up the mess, and I have found a bottom feed panel that will make life much easier, I hate working with #0000 aluminum wire.