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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sat Jun 05, 2010 11:42 pm Post subject: |
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OK, that's enough. I'm going to put a and to this bickering.
There's 6 large breasted naked women over at AVS right now looking for company. First come first serve.
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Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
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Sparky015
Joined: 12 May 2009
Posts: 1185
Location: Cleveland / Akron, OH
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| Posted: Sat Jun 05, 2010 11:42 pm Post subject: |
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| westom wrote: | Now you want explained appliance design - in a sound byte. OK. A datasheet that says 15,000 volts protection - your soundbyte answer that make you expert<cough>:
http://datasheets.maxim-ic.com/en/ds/MAX1487E-MAX491E.pdf
Obviously it says nothing useful. But if you want a propaganda answer in only 'black and white' simplicity - there it is - 100% complete protection. |
Westom,
Not that I want to get involved in this, but this is an IC that can handle 15KV of ESD (Eletrostatic Discharge). Huge difference from the topic at hand as ESD is a MUCH lower current than a lightening strike. It just means you can rub your feet on carpet and touch it and it will survive! 
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~Paul
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Sat Jun 05, 2010 11:49 pm Post subject: |
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| macgyver655 wrote: | | Just to recap for everyone else here, a good NEC recommended earth ground is going to help in the event of a power surge and some lightning strikes. |
Which only defines human safety. NEC says nothing about transistor safety. The world's best ground will do nothing if other incoming AC wires are not connected short to earth via a protector. And that is what experts have been saying for over 100 years.
Is that 100% protection? No. Facilities that never have damage enhance that earthing. Spend $thousands more to have a tiny more protection. It is still about the earthing.
Homeowners have no protection with even 1000 plug-in protectors. Most protection already exists in appliances. Properly earthing only one 'whole house' protector (that meets and exceeds code) means 99.5% to 99.9% protection. That is virtually 100% protection for any homeowner.
Of course, this is secondary protection. Those promoting myths also will not discuss the primary protection system. Homeowners should inspect primary protection. Picture of what to inspect:
http://www.tvtower.com/fpl.html
Each protection layer is only defined by the item that must harmlessly absorb energy. Single point earth ground. Only the better informed first discuss this most critical item in every protection system: single point earth ground. Those educated by sales brochures want to discuss 'magic boxes' that somehow make energy just disappear. Protection is always about where energy dissipates. A protector is only as effective as its earth ground. The effective solution also costs less money.
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Sat Jun 05, 2010 11:56 pm Post subject: |
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| Sparky015 wrote: | | Huge difference from the topic at hand as ESD is a MUCH lower current than a lightening strike. |
You and I both know that. But his complaint is that you have already posted too much information. You did not post a sound byte.
Of course that was obvious to anyone with minimal electrical knowledge. And so confusing to him. He is making claims, accusations, and inventing facts. But did not even know what you have just posted. That was the point. He had not a clue. He complains when simple concepts are explained so that he can learn. So I gave him a sound byte - a simplest datasheet. He could not even understand that. And yet he knows everything I posted is wrong. Go figure.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 12:03 am Post subject: |
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| westom wrote: | | Sparky015 wrote: | | Huge difference from the topic at hand as ESD is a MUCH lower current than a lightening strike. |
You and I both know that. But his complaint is that you have already posted too much information. You did not post a sound byte.
Of course that was obvious to anyone with minimal electrical knowledge. And so confusing to him. He is making claims, accusations, and inventing facts. But did not even know what you have just posted. That was the point. He had not a clue. He complains when simple concepts are explained so that he can learn. So I gave him a sound byte - a simplest datasheet. He could not even understand that. And yet he knows everything I posted is wrong. Go figure. |
I knew exactly what you posted and responded as such: http://www.curtpalme.com/forum/viewtopic.php?p=252827#252827
But whatever, your just worming around again.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 12:08 am Post subject: |
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| westom wrote: | | macgyver655 wrote: | | Just to recap for everyone else here, a good NEC recommended earth ground is going to help in the event of a power surge and some lightning strikes. |
Which only defines human safety. NEC says nothing about transistor safety. The world's best ground will do nothing if other incoming AC wires are not connected short to earth via a protector. And that is what experts have been saying for over 100 years. I am not and have not been disagreeing with this.
Is that 100% protection? No. Facilities that never have damage enhance that earthing. Spend $thousands more to have a tiny more protection. It is still about the earthing.
Homeowners have no protection with even 1000 plug-in protectors. Most protection already exists in appliances. Properly earthing only one 'whole house' protector (that meets and exceeds code) means 99.5% to 99.9% protection. That is virtually 100% protection for any homeowner. Again, you need to read those datasheets, thats not what is says and I'm not going to explain it to you.
Of course, this is secondary protection. Those promoting myths also will not discuss the primary protection system. Homeowners should inspect primary protection. Picture of what to inspect:
http://www.tvtower.com/fpl.html
Each protection layer is only defined by the item that must harmlessly absorb energy. Single point earth ground. Only the better informed first discuss this most critical item in every protection system: single point earth ground. Those educated by sales brochures want to discuss 'magic boxes' that somehow make energy just disappear. Protection is always about where energy dissipates. A protector is only as effective as its earth ground. The effective solution also costs less money. |
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 12:12 am Post subject: |
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| westom wrote: |
Of course that was obvious to anyone with minimal electrical knowledge. And so confusing to him. He is making claims, accusations, and inventing facts. But did not even know what you have just posted. That was the point. He had not a clue. |
I like this one. I dont think you will convince one person here that I dont have a clue when it comes to electronics.....
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 12:14 am Post subject: |
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| stefuel wrote: | OK, that's enough. I'm going to put a and to this bickering.
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I just figured you were enjoying the show. 
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 1:00 am Post subject: |
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Come on. I see your still logged on. Are you reading those datasheets?
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 1:09 am Post subject: |
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Alright, I'll have to come back tomorrow. I have to go fix some electronics stuff. For the life of me I can't figure out why this stuff fails. It must be these people without those special boxes. 
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Sun Jun 06, 2010 2:29 am Post subject: |
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| macgyver655 wrote: |
You see Westom. This is what an intelligent, knowledgeable post looks like. No copy and paste. And words of fact. |
Thankyou sir 
| stefuel wrote: | OK, that's enough. I'm going to put a and to this bickering.
There's 6 large breasted naked women over at AVS right now looking for company. First come first serve. |
Mate i havent got the energy for that today!! Hahahaha!! Thanks for the heads up all the same 
| westom wrote: |
None of this is for CasetheCorvetteman. He is entrenched in his myths. He demonstrates so many experts who know but forgot to first learn industry standards or basic design principles. Protection is always about where energy dissipates. Wall receptacle safety ground obviously is not earth ground. A protector is only as effective as its earth ground. |
Is that a fact is it? So all these times i hammered a big copper rod in the ground next to every main switch board and then wired it to the earth bar i mustve been just wasting my time was i?
Look at these pics:
Here you see the earth stake,
and the wiring to the earth stake,
Here you can see inside the box, youll see the MEN link between the neutral and earth for equipotential bonding:
And here, is another shot inside...
So you can see that the wire from the earth bar exiting through the bottom left of the box does indeed connect to the earth stake, and the earth stake is hammered into the ground around about 1800mm deep. How is this not "earth ground" as you call it?
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Cube
Joined: 06 Dec 2009
Posts: 77
Location: IL, USA
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| Posted: Sun Jun 06, 2010 7:15 am Post subject: |
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I'm confused about what protection exists inside appliances. What is it besides grounding? I thought ATX PSUs had the same kind of MOVs you would find in a cheap power strip.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Sun Jun 06, 2010 10:03 am Post subject: |
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I dont know for sure Cube, i havent opened up an ATX power supply for quite a while, but the last one i opened was an Aopen brand, so not real flashy, 450 watt, and had no MOVs in it.
As you probably allready know, the earth connection on appliances is there to provide a path of least resistance in the event that any conductive part of the appliance becomes live due to basic insulation failure or damage, so fault current will not travel through a person that comes into contact with it on its way to earth. Not sure what youd call them over there, but here in Australia they are called Class I appliances, and that protective earth has nothing to do with surge protection, it is only there to provide a safe path for a fault current to travel.
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Sun Jun 06, 2010 3:54 pm Post subject: |
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| Cube wrote: | | I'm confused about what protection exists inside appliances. What is it besides grounding? |
Grounding a power supply does nothing for surge protection. As CasetheCorvetteman notes, that ground is only a safety ground; not earth ground. If a supply has internal protection, then why do you assume it has MOVs? No reason exists to make that assumption.
An MOV inside a power supply must connect short (ie 'less than 3 meters') to earth. Obvoiusly, that will not happen. All appliances contain internal protection. One example is called galvanic isolation.
To have superior protection, MOVs are located as close to earth as possible. To enhance protection, telcos locate protectors up to 50 meters distant from electronics. Separation means a low resistance and higher impedance between MOV and electronics. Therefore better protection. Separation between MOV and electronics is necessary to enhance protection. But more important, if not connected short to earth, then energy does not dissipate harmlessly outside the building. To be effective, MOVs must make a short (ie ‘less than 3 meters’) to single point ground.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 4:02 pm Post subject: |
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| westom wrote: | | Cube wrote: | | I'm confused about what protection exists inside appliances. What is it besides grounding? |
Grounding a power supply does nothing for surge protection. As CasetheCorvetteman notes, that ground is only a safety ground; not earth ground. If a supply has internal protection, then why do you assume it has MOVs? No reason exists to make that assumption.
An MOV inside a power supply must connect short (ie 'less than 3 meters') to earth. Obvoiusly, that will not happen. All appliances contain internal protection. One example is called galvanic isolation.
To have superior protection, MOVs are located as close to earth as possible. To enhance protection, telcos locate protectors up to 50 meters distant from electronics. Separation means a low resistance and higher impedance between MOV and electronics. Therefore better protection. Separation between MOV and electronics is necessary to enhance protection. But more important, if not connected short to earth, then energy does not dissipate harmlessly outside the building. To be effective, MOVs must make a short (ie ‘less than 3 meters’) to single point ground. |
So what you are saying is that by mounting the MOV in the breaker panel and having it connected to a good earth ground (like your saying) it will divert the incoming surge directly to ground and therefore never make it to your electronics. So your electronics are protected. And the separation between the MOV and the electronics enhances that protection. Is that correct?
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Sun Jun 06, 2010 4:18 pm Post subject: |
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| CasetheCorvetteman wrote: | | So you can see that the wire from the earth bar exiting through the bottom left of the box does indeed connect to the earth stake, and the earth stake is hammered into the ground around about 1800mm deep. How is this not "earth ground" as you call it? |
That is an earth ground. Not considered sufficient in North America where rod must be at least 2500 mm - are more typically 3000 mm. Also not apparent is soil 'quality'. Geology is serious factor in how well the earthing is installed. Therefore many locations must use multiple 3000 mm rods, a buried loop, or Ufer grounds. That earthing is somewhere between minimal or insufficient.
Are those the only wires entering that building? If not, then earthing has been compromised. For example, if telephone also enters that building, then we should see a telephone earth ground wire also attached to that ground rod.
Ground wire goes down from the box and makes a sharp bend. Whereas that is sufficient for human safety, that sharp bend compromies earthing for transistor safety. That conduits (which cannot be metallic - is apparently plastic) should have angled directly to earth ground OR the earth ground should have been driectly below the box. Electricians do not like angles. It does not look clean. But angling or gentle sweeping turns are necessary for proper grounding.
Apparently this is an AC electric panel. That means one incomig wire is earthed. A protector in that box must connect other incoming wires to that bus bar. I only see circuit breakers. Therefore earthing has been compromised (for transistor safety). Wires have entered the building without first making a short connection to earth (via the bus bar and protector). Now direct lightning strikes connect to equipment inside the building.
Every wire in every cable from every utility service must connect to that earth ground rod. Either directly (as one AC wire is) or via a 'whole house' protector (which apparently does not exist).
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Sun Jun 06, 2010 4:24 pm Post subject: |
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| macgyver655 wrote: | | So what you are saying is that by mounting the MOV in the breaker panel and having it connected to a good earth ground (like your saying) it will divert the incoming surge directly to ground and therefore never make it to your electronics. So your electronics are protected. And the separation between the MOV and the electronics enhances that protection. Is that correct? |
That would be the sound byte answer - a minimal solution necessary so that surges (including direct lightning strikes) are harmlessly absorbed in earth.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Sun Jun 06, 2010 4:31 pm Post subject: |
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| westom wrote: | | macgyver655 wrote: | | So what you are saying is that by mounting the MOV in the breaker panel and having it connected to a good earth ground (like your saying) it will divert the incoming surge directly to ground and therefore never make it to your electronics. So your electronics are protected. And the separation between the MOV and the electronics enhances that protection. Is that correct? |
That would be the sound byte answer - a minimal solution necessary so that surges (including direct lightning strikes) are harmlessly absorbed in earth. |
Ok..
So what happens if the house is struck directly and now the surge has to travel through the wiring to get to the MOV in the box? Does it travel through various paths of the house just trying to get to earth not knowing which path is direct?
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David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
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| Posted: Sun Jun 06, 2010 5:33 pm Post subject: |
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Sharp bends do funny things at high current.
It behaves like a water hose and tries to un-bend itself.
If you look at starter cables for larger vehicles you can see them move. Not only due to the magnetic field.
Besides, even a small crack created by bending can fail miserably.
Hence grounding for lightning protection should not be bent. As mentioned by many papers and other reputable sources.
| westom wrote: | | All appliances contain internal protection. One example is called galvanic isolation. |
SELV was already mentioned. And no, not all appliances have it. It would actually be closer to "none" if you counted it.
Most appliances don't have any extra protection. At most it filters out noise and short sharp transients.
Many will take a larger hit without causing fire or other damage, but will die due to it. Which is not the same as survive.
A good ATX supply have a way better chance of not killing other equipment if it does fail. And can usually sustain more transients due to better filtering.
I think HardOCP had some analysis included about input filters/protection, can't find it now though.
Or it could have been another site.
When your house is hit directly all bets are off.
A family I know got hit by a rather nasty lightning bolt. I actually saw the same bolt from 3km away and it was thick. Made a beautiful sound though.
The wall sockets literally where blown out onto the floor. Cabinet doors flew open.
All electrical wire where evaporated leaving only ashes behind.
I have also heard of barbed wire getting hit, evaporating it, leaving only the links on the ground.
Ive probably forgot more stories than I know from people I have met and know.
The last really scary storm started in a minute with hail. One (I think) cloud to could bolt discharged only a hundred meter or so away. The light where so strong that you could hear it. Pretty blinding even in daylight. 1/3 of a sec later the sound hit, pretty loud I would say.
BTW have any of you seen greenish lightning?
Or completely silent (warm white) lightning?
The silent one have me puzzled, you can normally hear lightning many miles away, yet this was close with no hint of sound. Looked beautiful though with a warm yellow/white tint and what seemed to be a slightly longer presence.
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SNR of people are ridiculously low.
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betel
Joined: 20 Apr 2006
Posts: 448
Location: Maryville, Tennessee (Just South of Knoxville)
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