I wonder what's wrong with that.
Such parts are cheap, and this is DIYAudio.
Apart that your min. 4mA and max. 6mA requirements are awkward here in Europe.
Switzerland has 30mA, doesn't matter if its a mobile connector or a house installation, and you may have those which are arbitrarily delayed, i.e. they do not trip after two periods.
You could also use a Thermistor instead of a bridge. Pass Labs do that, AFAIK.
Me atypical (again).
1st (ground) floor bathroom, completely redone by a pro contractor ~5 years ago.
Earth net under the floor tiles, everything grounded, including the automated rinse & blow-dry toilet seater.
(2nd and 3d floor bathrooms are fully grounded too, combined electrical floor heating and earth net, with a connection to a GFCI, did those two myself)
Attachments
John (N)
The neutral and ground are supposed to be bonded at building entrance, as you know.
Now a typical domestic electric panel will have a neutral bar and an optional ground bar. If you look at a typical box the added ground bar is screwed to the metal box without insulation at the building entrance panel. The neutral is brought in to the neutral bar as it usually has a slot or two big enough for the neutral. Now if the installer ties the three (current code) ground rods (or pipe attachment) to the same neutral bar there is only conduction from the safety ground to the physical ground through the screws holding in neutral and ground bars through the case.
Another case would be if the grounding connection was only attached to the safety ground bar. In that case the current surge on the neutral could easily be large enough and fast enough that little is diverted to the grounding system. It gets worse on the older single ground systems.
Now take the worst case, a single ground to the isolated ground buss bar. A 12 gauge jumper to the neutral buss where the neutral is connected. That would have met code in the past. Then when lighting hits the neutral everything in the house frys!
As to the 6 volts permitted between neutral and safety ground. If more than even a few hundred millivolts is present the "safety" diodes begin to conduct! At 1.4 volts they will be close to their limit. As there is a limit on the 6 volts but not the current to produce the voltage, your diodes can fail even on an outlet that meets code.
ES
The neutral and ground are supposed to be bonded at building entrance, as you know.
Now a typical domestic electric panel will have a neutral bar and an optional ground bar. If you look at a typical box the added ground bar is screwed to the metal box without insulation at the building entrance panel. The neutral is brought in to the neutral bar as it usually has a slot or two big enough for the neutral. Now if the installer ties the three (current code) ground rods (or pipe attachment) to the same neutral bar there is only conduction from the safety ground to the physical ground through the screws holding in neutral and ground bars through the case.
Another case would be if the grounding connection was only attached to the safety ground bar. In that case the current surge on the neutral could easily be large enough and fast enough that little is diverted to the grounding system. It gets worse on the older single ground systems.
Now take the worst case, a single ground to the isolated ground buss bar. A 12 gauge jumper to the neutral buss where the neutral is connected. That would have met code in the past. Then when lighting hits the neutral everything in the house frys!
As to the 6 volts permitted between neutral and safety ground. If more than even a few hundred millivolts is present the "safety" diodes begin to conduct! At 1.4 volts they will be close to their limit. As there is a limit on the 6 volts but not the current to produce the voltage, your diodes can fail even on an outlet that meets code.
ES
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Good for you. That's one thing about high end,
as opposed to mass marketing, one has a little
more slack with the ' rules '.
Stuart Yaniger's sounds on SoundCloud - Create, record and share your sounds for free
Side note: "The Last Remaining Beatle" is a reworked version. In the original song, the first verse went:
"The last remaining Beatle will slaughter Michael Jackson
He'll strangle him to death while he's sleeping.
He'll strike with such a surgical precision, he won't even wake the preteen boys in the bed.
He'll take his clip on nose for a souvenir
and say, "The King of Pop is done here!"
Since the release of the album "Cruelty," Jackson died, so Southpaw (being a MUCH nicer person than I) rewrote that part to make it kinder.
Not a thing.. I though I made it very clear that I thought the idea great..
Hey, I'm the messenger here.. It's not my numbers, its per code here.
I teach an advanced ele safety course here, I get somewhat annoyed at how they keep changing the "lethal" level of current this side of the pond. Sigh...what, are they testing that??? Who would volunteer to be a subject??
They also do not meet safety with bolted fault. However, once a GFI is there, no problem. In fact, once a GFI is there, you could conceivably use a 5 or 10 volt power zener pair in anti-series.
Mine has one. But I can't speak for legacy equipment. I do know that I did have a 50 amp sub-panel where the option to connect neutral to box was there, ground was directly tied to the box. At the time, I had no clue why the option was there. Now I know that as a sub panel, you must break the neutral to box connection... If you do not, the ground conductor will be carrying neutral current all the way back to the main panel, that is a violation. Grounding conductors must carry no load current normally.
That's why Ive been discussing the bolted fault current and what diodes are capable of handling.
You mention 6 volts again...is that code somewhere? I recall a 50 volt code for voltage classification, but I don't recall 6.
j
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Welcome to my world! Most electricians isolated the safety ground buss from the box, as the neutral buss comes installed!
The six volts is from the test for ground conduction. You insert a 40 amp fuse in a hot leg and short it to ground. If the fuse blows the ground is good. Really! The code calls for 3 ohms or less. Then you look at the permitted unbalance current typically 10% for residential unit. So a 200 amp panel can have 20 amps or 6 volts!
ES
3 ohms for which? Residential earthing is 25 ohms max.
I times R = V
20 times 3 equals 60. (don't worry, my math is just as bad once the numbers are more than my finger total..)
Do you mean .3?
j
Geberit : ---The Geberit ShowerToilet---
Not too pleased about the engineering inside (but then, i've always been somewhat of an arrog... pri.. )
On the right side of the grounded in-wall socket => http://www.diyaudio.com/forums/pass...high-end-off-topic-thread-22.html#post2126573
(when the moment comes of doing myself in, i sure know where to do it)
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Thanks for the info.
From the first listening, Lee Barber’s recording sounds to me better tonally balanced, having more mid-low freq. content, while Southpau’s a bit brighter. But again, different guitars, different voices.
Just one more question: Was Lee Barber sitting in the same place as Southpau on the photo and SY’s crossed ribbons at approx. the same position as Scott’s condensers?
The reason I ask is that after 2-3 listenings, I perceive Lee Barber’s capture as having “space around him”, while Southpau more as “him placed on a screen”.
May be, the seat and back panel of the folded chair have done some things to the received sound. (condensers are also both facing forward).
At a feature recording event, since your floor is concrete, you may try placing the mikes directly on the floor (ground plane arrangement).
This technique started from speech recording studios, moving to live opera recordings - on at least one - important stage(s) already some years ago.
Multipath effects minimization in theory.
Better speech intelligibility and better space ambience information capture in practice.
In your case, it will save one chair too.
George
The carpet and pad are an issue for PZM-style miking. I'm interested in trying a suspended version similar to Pierre Sprey.
Lee was sitting a bit farther out into the room, maybe an extra meter. The mike polar pattern differences are very much responsible for the imaging and soundstage variations. I like the midrange tonality of the ribbon better, but the definition and high treble of Scott's mikes wipe mine out.
We had quite a few forum members present for these shows; it's an amazing amount of fun. BTW, the box on the left where my guitars and banjos are leaning is one of my subwoofers. It doubles as a printer stand and a convenient place to leave my wine glass.
Lee was sitting a bit farther out into the room, maybe an extra meter. The mike polar pattern differences are very much responsible for the imaging and soundstage variations. I like the midrange tonality of the ribbon better, but the definition and high treble of Scott's mikes wipe mine out.
We had quite a few forum members present for these shows; it's an amazing amount of fun. BTW, the box on the left where my guitars and banjos are leaning is one of my subwoofers. It doubles as a printer stand and a convenient place to leave my wine glass.
Remove the outlet cover screw. Plug it in. Put the outlet cover screw back in through the hole in the tab on the plug.
Even though older homes were wired with two prong outlets, the in-wall wiring usually used three conductor cable with the safety ground connected to the metal outlet box (same with the metal boxes for light fixtures).
se
Remove the outlet cover screw. Plug it in. Put the outlet cover screw back in through the hole in the tab on the plug.
Even though older homes were wired with two prong outlets, the in-wall wiring usually used three conductor cable with the safety ground connected to the metal outlet box (same with the metal boxes for light fixtures).
se
Yes, BX cable had and outside metal sheath and they didn't have plastic work boxes back then.
You might still want to check the outlet with one of those little thingies with the three lights.
George,
I had some trepidation in doing an actual music recording since I know a few folks who do this very seriously and was sure there were going to be several "rookie" mistakes. I thank Rob Danielson for pointing out the same rig with omni capsules made nature recordings that were a little too bright and recommended the cartiod capsules to temper this. As you noticed the image is a little flattened front to back, the omnis get the opposite comment in this regard (some of my fields recordings were almost binaural to some). As I said in my article this is where engineering and art coincide.
I've been assured by a real Master Electrician that it's (USA) code to install a GFI outlet in place of a two wire outlet.
Thanks,
Chris
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