ProSoundWeb Community
Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => AC Power and Grounding => Topic started by: Frank DeWitt on December 26, 2013, 10:48:49 PM
-
http://www.youtube.com/watch?v=D5ol5XKjKQo#t=328
Connect the hot to the silver screw, and the neutral to the brass screw and the ground to something.
Gulp.
-
http://www.youtube.com/watch?v=D5ol5XKjKQo#t=328
Connect the hot to the silver screw, and the neutral to the brass screw and the ground to something.
Gulp.
And I wasted all those years studying electrical engineering... Who knew you didn't have to keep track of the wire or screw colors? ???
Here's another one where he's more interested in the colors of the wall plate than the actual safety ground. http://www.youtube.com/watch?v=bnGERqjgrzA
When I first started writing about RPBG wiring (Reverse Polarity Bootleg Grounds) the test gear manufacturers had the gall to ask me how they could happen. These guys are proof of just how dangerous the DIY movement can be without proper training. Yikes!!!
-
And I wasted all those years studying electrical engineering... Who knew you didn't have to keep track of the wire or screw colors? ???
Here's another one where he's more interested in the colors of the wall plate than the actual safety ground. http://www.youtube.com/watch?v=bnGERqjgrzA
When I first started writing about RPBG wiring (Reverse Polarity Bootleg Grounds) the test gear manufacturers had the gall to ask me how they could happen. These guys are proof of just how dangerous the DIY movement can be without proper training. Yikes!!!
Haha, yeah, "crimp connectors, I don't know if I will need them." And the wire nuts also have some white colored ones that will match your plate covers! Woo hoo! Appears that he intends to ground the plug to the outlet box. Hoping that it's metal, of course...
People must be watching this idiocy, though.
-
Haha, yeah, "crimp connectors, I don't know if I will need them." And the wire nuts also have some white colored ones that will match your plate covers! Woo hoo! Appears that he intends to ground the plug to the outlet box. Hoping that it's metal, of course...
People must be watching this idiocy, though.
I think a response to that video is in order:
"If you do electrical work based on this video, please leave it on screen so your survivors know who to sue when you get electrocuted or your house burns down."
-
I think a response to that video is in order:
"If you do electrical work based on this video, please leave it on screen so your survivors know who to sue when you get electrocuted or your house burns down."
Ha! :o
When I was a young EE back in the 70's you could only purchase electrical panel boxes and circuit breakers if you had some sort of electrical license. Just that fact is one of the reasons I went for my Master Electricians License. I could simply flash my electricians card and buy anything I wanted at the electrical distributors. Nowadays, anybody can buy anything they want at any big box store up to and including service panels and j-boxes as long as they have cash or a credit card. I'm pretty sure that 99% of the customers buying these electrical parts at Lowes and Home Depot are not qualified to install or test any of it. I'm sure they will YouTube these same videos just to make sure they have the right color wall plates and wire nuts.
I never knew the wire nut color needed to match the wall plate color either. I must have slept through that class.
I don't have the time, but somebody should be searching YouTube for this sort of garbage and calling them out. They're going to get somebody killed.
-
Frank: What a great thread... ;D
If any of you see stupid YouTube videos about electrical wiring, please post them here.
-
Frank: What a great thread... ;D
If any of you see stupid YouTube videos about electrical wiring, please post them here.
What struck me about this is that I know enough about this subject to have completely wired two houses (Both my own) but because I am not a professional I would never consider giving advice or making a you tube video on the subject. I just installed a carillon system in a local church including some extensive wiring to the speakers in the steeple but I told them they needed to have a electrician install a new outlet and gave them a name. There was a J box above the suspended ceiling tiles 5 ft from where I needed an outlet and it looked new enough to trust it but just don't do that. Instead some guy that doesn't know the hot from the ground makes the you tube. BTW did anyone spot the guy that said the old ungrounded outlet was installed upside down because it had the wide slot on the right? He held up a grounded outlet in the smile face orientation to show that the wide slot should be on the left.
-
BTW did anyone spot the guy that said the old ungrounded outlet was installed upside down because it had the wide slot on the right? He held up a grounded outlet in the smile face orientation to show that the wide slot should be on the left.
These guys fixate on unimportant details like the color of the wire nuts or orientation of the outlet. The orientation of the receptacle (ground hole top or bottom) isn't specifically established by the NEC. In fact, there's been an ongoing discussion that orienting receptacles with the ground contact on the top might be safer, considering that a metal outlet cover with a lost screw would fall down on the ground pin, and not short across the hot and neutral blades of the plug. Don't know if there's been a consensus in the 2014 code release, but I'll take a look when I a get a copy.
Too much fun! 8)
-
In fact, there's been an ongoing discussion that orienting receptacles with the ground contact on the top might be safer, considering that a metal outlet cover with a lost screw would fall down on the ground pin, and not short across the hot and neutral blades of the plug.
At the risk of bringing up that debate here...
I think having the ground pin at the top is only marginally safer and any sense of security is misguided. When the plate falls off the receptacle and lands on the ground pin, there's a high likelihood that it will still come in contact with the hot pin as it swings around. If you're worried, put some removable threadlocker on the screw. Plus, it doesn't do any good if you've plugged in a 2-prong plug. The best, most logical argument I've found for placing the ground pin down is because the wife likes it that way.
I remember an incident when I was a child. In my parents' bedroom, the bedside lamp was plugged in a few feet away, so the cord was hanging in the air between the receptacle and the lamp. There were a number of metal coat hangers on the floor. I was idly playing, hanging the coat hangers on that wire, evenly spaced. The last space was to hang one on the plug. The coat hanger slipped between the plug and the receptacle and POW! (I wasn't shocked, but it kind of scared me.)
As the lamp had a 2-prong cord, it wouldn't have mattered which way the ground pin was oriented, up or down. (For that matter, orienting it sideways with neutral on top might've been a little better, but hardly safer.) My memory cells are picturing a 2-prong, ungrounded receptacle there.
That highlights a flaw in northwestern-half-hemisphere (what do you call half a hemisphere?) electrical design: a plug partially removed exposes live electrical contacts. Were the receptacle recessed, or the prongs equipped with spring-loaded, retractable covers, that hazard would be minimized. I believe many European receptacles are recessed now.
Nearly every refrigerator I've seen has a right angle plug, with the ground pin opposite the side of the plug where the cord enters. Therefore, refrigerator receptacles should be installed ground pin up to relieve strain on the cord. But not every right-angle plug has the ground pin so oriented; so it's probably best to orient the receptacle whichever direction results in the least strain on the cord. (As if you can predict that. There are doubtless refrigerators out there with the ground pin on the same side as the cord.)
-
If any of you see stupid YouTube videos about electrical wiring, please post them here.
Not videos, but go to ashireporter.org (http://www.ashireporter.org/), then click on "Past Issues", select an issue, then "Postcards from the Field."
-
Australian mains plugs now have insulated pins (insulation covers half the length of the L and N prongs) to mitigate the risk of things slipping between the power outlet and the plug.
Chinese power outlets have nearly identical geometry to Australian outlets except they are installed "upside down" with the ground pin at the top to reduce the risk of something slipping into the outlet/plug gap.
The logic around the Australian orientation was that a common accidental disconnection (such as stepping on the appliance cord) would result in a downwards force; with the ground prong at the bottom ground will disconnect last in this scenario. In any case, the ground prong is also longer than L and N to ensure it is the last to disconnect.
-
Ground up Check
Ground down Check
(http://electrical-contractor.net/BCodes/condulet_recpt_1.JPG)
-
Appears that he intends to ground the plug to the outlet box. Hoping that it's metal, of course...
Sheetrock wall, wood framing, NM wiring-"grounding" to metal box or pvc-same difference!
Love to see them try to get this one installed the right way! Receptacles rotate however you want them-I don't really like them, but they are UL listed and if you have 2 cords to plug in with 90 degree plugs and the same ground pin orientation about the only way I know to do it in a single gang.
-
And I wasted all those years studying electrical engineering... Who knew you didn't have to keep track of the wire or screw colors? ???
Here's another one where he's more interested in the colors of the wall plate than the actual safety ground. http://www.youtube.com/watch?v=bnGERqjgrzA
When I first started writing about RPBG wiring (Reverse Polarity Bootleg Grounds) the test gear manufacturers had the gall to ask me how they could happen. These guys are proof of just how dangerous the DIY movement can be without proper training. Yikes!!!
wait till they come upon some of that old wire with the rubber and cloth insulation. the insulation usually disentergrates.
-
These guys fixate on unimportant details like the color of the wire nuts or orientation of the outlet. The orientation of the receptacle (ground hole top or bottom) isn't specifically established by the NEC. In fact, there's been an ongoing discussion that orienting receptacles with the ground contact on the top might be safer, considering that a metal outlet cover with a lost screw would fall down on the ground pin, and not short across the hot and neutral blades of the plug. Don't know if there's been a consensus in the 2014 code release, but I'll take a look when I a get a copy.
Too much fun! 8)
sometime during the 90's california required the ground to be on top. it came about when an office caught fire and a few people were killed. the investigators determined that the cause was caused by a paper clip that fell behind a desk and fell right on top of the hot and neutral of a plug that wasnt pluged all the way in to the receptical. they found the circut breaker had not tripped and that the short became hot enough to ignite the plug,wall plate and wall paper. they said the old wall paper was very flamable and was the glue. it spread quick and trapped some people. there were no sprinklers. after some test they found that if the ground prong was on top and the plug wasnt all the way in any metal that fell on it would fall off. some years later the inspectors told us we no longer had to put the ground hole on top. further testing revealed that if a metal object like a paper clip hit the ground prong and rotated and hit the hot while still touching the ground it would weld itself to both and a fire could still happen.
-
sometime during the 90's california required the ground to be on top. it came about when an office caught fire and a few people were killed. the investigators determined that the cause was caused by a paper clip that fell behind a desk and fell right on top of the hot and neutral of a plug that wasnt pluged all the way in to the receptical. they found the circut breaker had not tripped and that the short became hot enough to ignite the plug,wall plate and wall paper. they said the old wall paper was very flamable and was the glue. it spread quick and trapped some people. there were no sprinklers. after some test they found that if the ground prong was on top and the plug wasnt all the way in any metal that fell on it would fall off. some years later the inspectors told us we no longer had to put the ground hole on top. further testing revealed that if a metal object like a paper clip hit the ground prong and rotated and hit the hot while still touching the ground it would weld itself to both and a fire could still happen.
I've seen a guitar string laying over someone's amp in a practice room fall off the amp and land across the hot and neutral of the amp's plug in the receptacle. Made a nice flash and burn but did trip the breaker.
-
That highlights a flaw in northwestern-half-hemisphere (what do you call half a hemisphere?) electrical design: a plug partially removed exposes live electrical contacts.
Not the UK plug. It is half insulated so that if it is inserted just enough to make contact, only the plastic parts are exposed on both live and neutral.
(http://www.thetoolboxshop.com/user/products/0-684-01-1-single-13amp-plug-top-with-sleeved-pins-7532-p.jpg)
(quadrasphere?).
Steve.
-
Not the UK plug. It is half insulated so that if it is inserted just enough to make contact, only the plastic parts are exposed on both live and neutral.
The American "Edison" plug can also be a shock hazard across your fingers if you slip while plugging it into an extension cord partially. I do like the Neutrik PowerCon connectors that Whirlwind uses to interconnect their PowerLink product line.
-
Back OT. Here's a video for dummies who need to replace an existing electrical outlet. It's not terribly bad, except for two glaring mistakes and some lack of info.
http://www.youtube.com/watch?v=vfZAE1VQPEY
#1 They don't have you test the meter first to see if it's working before turning off the circuit breaker (actually a 3-light cube tester would be better for this, I think). If the meter was set improperly, then it would show zero volts even on a live circuit.
#2 There's a lot of bare wire extending past the screws and looks like it would contact the side of the box. I always make sure any bare wire is trimmed back tight to the screw head, plus add a few wraps of electrical tape around the receptacle to insulate the screws from any accidental side contact.
#3 They don't mention what the breakout tab does, which of course is for a combo switched/unswitched receptacle.
-
When I first started writing about RPBG wiring (Reverse Polarity Bootleg Grounds) the test gear manufacturers had the gall to ask me how they could happen. These guys are proof of just how dangerous the DIY movement can be without proper training. Yikes!!!
Maybe some common sense would help. It does not take an EE to replace an outlet properly. Pay attention and put things back the way one finds them (assuming it was correct when approached). Unfortunately, most of the remaining common sense is either educated, trained, or litigated out of the populace. (sigh)
As for outlet orientation - in new construction - how about a sideways orientation of the box and outlet so neutral is up. With a 3-prong, the hot would be well shielded, and with two prong, it would be that much tougher for an accidental short beween neutral and hot. Of course, if the outlet were turned upside down (hot top) would be more dangerous.
It would take a bit for the decorators to adjust...
As far as recessed receptacles, what to do about wall warts?
-
Maybe some common sense would help. It does not take an EE to replace an outlet properly. Pay attention and put things back the way one finds them (assuming it was correct when approached). Unfortunately, most of the remaining common sense is either educated, trained, or litigated out of the populace. (sigh)
My own kids have been taught about technical things while still sitting on my knee. So they can now troubleshoot and swap circuit boards in a computer or change out the starter on their cars. But the college students at the conservatory where I teach seemed to have missed this upbringing and have a lot of trouble with some of the simplest things such as setting a DMM to read AC volts. But they have no trouble running and bragging about their iPhone apps.
I have a 90-minute NoShockZone seminar I do at Recreational Vehicle shows where I define volts, amps and watts, then demonstrate how to safely meter and plug into a campsite power pedestal and check thier RVs for a hot-skin shock condition. I've had 80 year-old grandmothers come up to me after the presentation and tell me the now understand electricity, when they've struggled with the concept their entire lives. RV owners have to worry about this more than most since every time they plug into a new power source, the voltage can be too high or too low, and sometimes the ground is disconnected at the campsite pedestal outlet. Sadly, there's nothing in the NEC that requires any sort of periodic testing of power outlets at campgrounds and boat docks. So campers need a basic understanding of what electricity is and when to get worried (any kind of electrical shock).
I've found that many (most?) consumers believe that since electricity is invisible that it's too complicated to understand. But a little common sense about electricity goes a long way towards electrical safety. Unfortunately, most schools don't teach common sense, only how to pass standardized tests. So if you do understand electricity, then I challenge each of you to mentor someone (a young sound tech or maybe your own kid) about how cool electricity is. This can be as simple as an LED bulb and a battery to discuss voltage and current flow, or as complicated as building a real circuit. FYI: I see that Heathkit may once again be offering their great projects (which I built as a kid) and Radio Shack has a great DIY electrical program with all sorts of cool kits. To me, that's more important than making sure a kid has the latest smartphone or tablet.
-
But the college students at the conservatory where I teach seemed to have missed this upbringing and have a lot of trouble with some of the simplest things such as setting a DMM to read AC volts.
A few years ago, my company hired someone with an electronics degree. He came to me (an engineer without a degree) and asked which way round to connect an LED.
I do like the Neutrik PowerCon connectors that Whirlwind uses to interconnect their PowerLink product line.
I like all of Neutrik's products. Their UK factory is only about a mile away from me. If I ever lose my current job, I think I would call on them first.
Not the UK plug. It is half insulated so that if it is inserted just enough to make contact, only the plastic parts are exposed on both live and neutral.
When I was at school (70s and 80s) our plugs didn't have the insulation on the live and neutral pins like in the picture I posted. They were solid brass. This made it very easy to connect something without actually putting a plug on it. Hold the bared wire ends over the holes in the socket and push in the plug from something else!
Steve.
-
A few years ago, my company hired someone with an electronics degree. He came to me (an engineer without a degree) and asked which way round to connect an LED.
Sadly about 25% of job applications contain outright fabrications. More than half contain misleading statements about levels of responsibility that stretch the truth.
That said, EE is a wide field. An EE could be forgiven for forgetting which end of the led has a long lead.
... but they should have worked it out for themselves with a meter to save face :-)
-
Sadly about 25% of job applications contain outright fabrications. More than half contain misleading statements about levels of responsibility that stretch the truth.
Are you talking about about job applications or Youtube "How to" videos?? :D
-
SThat said, EE is a wide field.
Yes. I later found out that the title of his degree was Electronic Systems Design. I think anyone who could draw a block diagram could get one!
Steve.