|   Is AC wall-outlet grounding absolutely necessary ? | Simon Lee
Nov 21, 2001 4:44 AM | | Hi,I am looking for a Power Conditioner which will work well on an
UNGROUNDED AC wall outlet(my house condition is as such). A well-known
US cable manufacturer have told me that their Power AC Outlet Center(audiophile power cord with attached pancake-like outlet)contains no filtering and require no grounding and work well .I am skeptical about this. I really need your opinion/experiences,suggestion so that be sure I can go with the power conditioner without worrying not getting benefit from it .Thanks a lot.
Simon |
| re: Is AC wall-outlet grounding absolutely necessary ? | Monstrous Mike
Nov 21, 2001 11:06 AM | | An earth ground and signal ground are included in electrically powered equipment for protection reasons. There is a need to protect both the equipment and the human beings around the equipment from shock and fire due to electrical shorting.
Almost all home audio equipment does not have an earth ground since ground loops between the earth and system grounds are a major cause of noise and hum in audio systems. For safety, the power connections and system grounds are double shielded instead.
For more info read: http://www.epanorama.net/documents/groundloop/index.html |
| Ground up by an unfound ground-will I become ground round? | itellitlikeitis
Nov 22, 2001 7:30 AM | | If you live in an old house like I used to and all of the wall outlets have no ground pin, then you've probably been going nuts buying three prong to two prong adaptors all your life. However, even those outlets have the screw that holds the cover plate grounded to the house ground through the ground wire in the bx or romex if it was installed properly. Attach the adaptor's green wire with the small spade lug to this screw and you'll be grounded. If your equipment came with no ground wire, it got a UL listing without needing one. Don't worry about it.
Frankly, having purchased enormous amounts of power conditioning and UPS equipment over many years as part of many electrical projects, I am very skeptical of most of these so-called audiophile power conditioners. Many of them are nothing more than MOV devices in a fancy power strip, maybe a small capacitor or two, with fancy packaging, and a fancy price tag. I'd be very careful and find out exactly what I'm getting and how it's suppposed to work. Personally, I'd prefer a small UPS. |
| UPS Bad Advice | Jon Risch
Nov 23, 2001 3:14 PM | | Most UPS devices on the market, are intended for use with computers, using switching power supplies.
They have a step-wise type of waveform, with lots of harmonics and noise on them, and are NOT designed to drive the typical analog transformer based power supplies that most audio components use. They can even blow up trying to do so.
Very bad advice.
Jon Risch |
| re: Is AC wall-outlet grounding absolutely necessary ? | Jon Risch
Nov 23, 2001 3:11 PM | | If your outlets have a grounde wall plate, then I would attach the grounding adaptor to this AS IT WAS INTENDED TO BE USED, and this would ground the components.
Normally, three prong plugs need to be grounded, or it is possible that certain types of internal AC filtering will not occur as intended, and the safety of the component may be compromised.
It is possible for AC filtering action to occur without a connection to the thrid pin ground, so this is not some sort of mystery.
Chang Lightspeed AC power filters can do this, although I do believe they have a ground connection. The principle that the device operates on (massive close-intimacy ferrite style filtering) would be able to filter without a ground connection, and there are many other ways to do so.
Jon Risch |
| re: Is AC wall-outlet grounding absolutely necessary ? | Simon Lee
Nov 24, 2001 8:44 PM | | Thanks Jon:JpsLabs claimed that their GPA Power AC-outlet Center
contains no filtering and require no grounding and work well.I just don't get it-How without a filtering be able to "clean" the AC power?
I really need your expertise explaiantion and thanks again
Simon |
| re: Is AC wall-outlet grounding absolutely necessary ? | Jon Risch
Nov 25, 2001 10:43 AM | | Ferrite beads, immersing a length of wire inside a container of ferrite or iron powder, placing a conductive fluid next to the wires, an isolation transformer, all of these can 'clean' the AC power without overt obvious filtering action.
It seems as though JPS Labs is avoiding the F word, perhaps it is perceived as a bad thing?
If one were to call something filtering, then a cap across the Hot and Neutral will work without a ground connection, an isolation transformer with balanced AC power output will also provide a 'cleaning' function, but that does require a ground connection.
Jon Risch |
| |
