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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Sun Jun 06, 2010 10:04 pm Post subject: |
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| westom wrote: |
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. |
There is no telephone cable.
| westom wrote: |
Electricians do not like angles. It does not look clean. But angling or gentle sweeping turns are necessary for proper grounding. |
I AM an electrician mate, and that angle bent into that conduit is well within the specs for minimum bend radius.
| westom wrote: |
Apparently this is an AC electric panel. |
Ya think? 
| westom wrote: |
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. |
Do you see a busbar in there with all your infinite electrical trade knowlege? I dont, and i filled the board. There is 3 phase supply, supplying the bottom of each breaker, including the 4 pole RCD and the 2 pole RCBO. There is no bus bar inside that board. 3 actives, 1 neutral, 1 earth, no busbars.
At the time those pictures were taken the board and that work were incomplete, and the metering device had not been installed.
| westom wrote: |
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). |
They are, as you can partly see there in my pictures.... If you connect the actives to the ground rod, youll blow the pole fuses, due to a pretty near dead short between active and ground.
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sun Jun 06, 2010 10:29 pm Post subject: |
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| macgyver655 wrote: | | 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? |
It takes the path of least resistance which is usually a $50,000.00 projector and leaves the coffee maker alone 
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A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Mon Jun 07, 2010 1:01 am Post subject: |
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| CasetheCorvetteman wrote: | | I AM an electrician mate, and that angle bent into that conduit is well within the specs for minimum bend radius. |
Which says you know only what code requires (for human safety) and have not a clue what impedance is.
Surge protection means meeting and *exceeding* code requirements. Electricians who only know what they are told to do (for human safety) would not understand why that sharp bend compromises earthing.
Protection is about every incoming wire in every cable connected short to that earth ground. Protection is always about where energy dissipates. Protection is about meeting and *exceeding* code because a protector is only as effective as its earth ground. That sharp wire bend meets code and is bad for surge protection. Not that you will hear any of this. A concept called impedance repeatedly escapes you since code does not require you to understand it. Why that ground rod meets code and may be insufficient for surge protection - again you deny rather than learn.
| Quote: | | If you connect the actives to the ground rod, youll blow the pole fuses |
No matter how many times I explain it, your 'superiority' will not let you learn. Every incoming wire must make a short connection to earth. And again, either directly or via a protector. It means you must understand a concept explained at least eight times - and you still don't get it. Your panel and its earthing encourages a surge to seek earth destructively inside that bulding. If only an electrician, you would not understand.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Jun 07, 2010 1:38 am Post subject: |
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| westom wrote: | | CasetheCorvetteman wrote: | | I AM an electrician mate, and that angle bent into that conduit is well within the specs for minimum bend radius. |
Which says you know only what code requires (for human safety) and have not a clue what impedance is.
Surge protection means meeting and *exceeding* code requirements. Electricians who only know what they are told to do (for human safety) would not understand why that sharp bend compromises earthing.
Protection is about every incoming wire in every cable connected short to that earth ground. Protection is always about where energy dissipates. Protection is about meeting and *exceeding* code because a protector is only as effective as its earth ground. That sharp wire bend meets code and is bad for surge protection. Not that you will hear any of this. A concept called impedance repeatedly escapes you since code does not require you to understand it. Why that ground rod meets code and may be insufficient for surge protection - again you deny rather than learn.
| Quote: | | If you connect the actives to the ground rod, youll blow the pole fuses |
No matter how many times I explain it, your 'superiority' will not let you learn. Every incoming wire must make a short connection to earth. And again, either directly or via a protector. It means you must understand a concept explained at least eight times - and you still don't get it. Your panel and its earthing encourages a surge to seek earth destructively inside that bulding. If only an electrician, you would not understand. |
Hey, butthead. Answer my question. Instead of telling everyone else they dont know what they are talking about.
And did you read those datasheets yet?
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Mon Jun 07, 2010 9:32 am Post subject: |
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| westom wrote: | | Which says you know only what code requires (for human safety) and have not a clue what impedance is. |
Impedance is the opposition to current flow. End of story, there is NO other explaination for the word impedance when speaking electrical terms.
| westom wrote: | | Electricians who only know what they are told to do (for human safety) would not understand why that sharp bend compromises earthing. |
I understand perfectly well. The downside to the bend is potential eddy currents. A bend that large a radii wont be an issue. Itll never carry enough current to be a concern.
| westom wrote: | | Protection is about every incoming wire in every cable connected short to that earth ground. |
Get real man, how stupid a statement is that? If you connect an active conductor to ground, the difference in potential is at what ever the mains supply for the given area is, assuming either 110v or 230v in this case, youve got a dead short, so we will call that 0.2 ohms, whether you like it or not V= I x R, so at 230 volts and 0.2 ohms that is around 1,150 amps will flow. Earth is at equal potential to Neutral. Why the hell would anyone think you can or even should connect an active conductor to the ground? That's the dumbest fn thing ive ever heard.
| westom wrote: | | That sharp wire bend meets code and is bad for surge protection. |
1) the bend aint sharp and 2) itll have no bearing on surge protection, there is none fitted to that board.
| westom wrote: | | Not that you will hear any of this. |
Ofcourse i wont, cause its all gobblety goot. You cant connect an active conductor to earth for a start.
| westom wrote: | | No matter how many times I explain it, your 'superiority' will not let you learn. Every incoming wire must make a short connection to earth. |
Show me, make a video, upload it and show me what happens when you connect an active conductor dirrectly to earth. Prove your theory to me that active can be connected to earth.
| westom wrote: | | It means you must understand a concept explained at least eight times - and you still don't get it. |
Must have something to do with the concept of connecting active to ground. Ill get it when you show me.
| westom wrote: | | Your panel and its earthing encourages a surge to seek earth destructively inside that bulding. |
What a crock of horseshit. How do you figure that? Do you see what the building is made of? Steel. And what is steel? its a conductor. What is the steel shell connected to? The steel frame. What is it fastened to? To the ground with large dynabolts into a concrete slab full of reinforcing steel, that is wired in numeous places to different pieces and also to the steel building, the reinforcing steel goes 3 meters deep into the ground in 3 places on one side, and 1.2 meters deep in 3 places on the other. How is that box fastened to the wall you ask? Well its attached with 15 hex head screws, and no less than 5 earth wires going ONLY to various parts of the steel building to ensure equipotential bonding of the shell, the frame, and the slab reinforcing. You can take a multi meter and measure continuity ANYWHERE in that building from any steel item back to the earth bar, and not one reading was more than 0.2 ohms, and that includes the cable required to measure far apart points.
After all that, what is this building sitting on? THE EARTH. You cant tell me that building is not well connected to earth.
| westom wrote: | | If only an electrician, you would not understand. |
And in what trade do you profess and in which country do you practice this trade?
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Mon Jun 07, 2010 10:18 am Post subject: |
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WOW, I've learned soooo much in the few times I've visited this thread. I've just now realized that I'm a complete moron.
Re-cap, OK I should have my "actives" (line 1 and line 2) directly connected to "earth ground". What a novel concept.
Hmmm, OK, what part does the "neutral" play in this? Last time I looked (at least in the US) the neutral and "earth ground" are common with both directly connected within the breaker panel.
I guess the power company must be sending SMART ELECTRONS down the pipe that will only go to approved loads
Kind of like HDMI. The electron must handshake whth the toaster oven before it can make toast. 
No handshake with the direct short so the electrons won't go there
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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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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Mon Jun 07, 2010 1:57 pm Post subject: |
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| CasetheCorvetteman wrote: | | Show me, make a video, upload it and show me what happens when you connect an active conductor directly to earth. |
It is amazing that a junior electrician cannot read. Obviously the active conductor is not hardwired to earth – as stated so many times. Every conductor that cannot be hardwired to earth must connect to earth via a protector. Now explained for at least the ninth time. And you still cannot understand it. Did you take remedial reading in electrician school?
Mankind has understood this even 100 years ago. It is standard in munitions dumps, communication switching centers, Air Force bases, broadcast stations, nuclear hardened facilities, and rocket launching facilities. Anywhere that damage cannot happen. And still an electrician cannot understand these simplest electrical concepts.
Of course not. This is not about your education. This is about your ego. You did not know. Therefore it must be wrong.
Stefuel, why are you just as confused? Your "actives" (line 1 and line 2) directly connected to "earth ground" ... via a 'whole house' protector. Why do you read partially or subjectively? To be as obstinate and anti-social as CasetheCorvetteman? It is not difficult. Every incoming wire must make a short connection to single point earth ground - either hardwired (ie AC neutral, cable TV, satellite dish wire) or via a 'whole house' protector (AC hot, telephone wires). Why is 100 years of well proven knowledge so hard to learn?
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Mon Jun 07, 2010 2:31 pm Post subject: |
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Why do you not answer my questions? I understand what your talking about. But you repeatedly ignore my questions. You must be uninformed and confused. You have not learned from your own answers. You only know what you know. You know what others say. You CnP what you dont know. You dont read to learn what you read. Then you attempt to misinform others with misinformation. And I've repeated this 8 or more times. And you still dont learn. You dont answer direct questions. Because you dont know. And you cant find an answer to CnP. Illogical, illogical........must be destroyed.......
Beam him up Scottie.........
I have a great suggestion for you. Why not go and find a web site for professional electricians and have your conversations with them. Then if you can convince them that your method is in fact what you say, post a link here and I will gladly read it.
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dturco
Joined: 06 Feb 2009
Posts: 3778
Location: Eastern Shore Maryland
TV/Projector: Runco DLP VX-3000i Marquee 9500 parts doner
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| Posted: Mon Jun 07, 2010 8:45 pm Post subject: |
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| stefuel wrote: | WOW, I've learned soooo much in the few times I've visited this thread. I've just now realized that I'm a complete moron.
Re-cap, OK I should have my "actives" (line 1 and line 2) directly connected to "earth ground". What a novel concept.
Hmmm, OK, what part does the "neutral" play in this? Last time I looked (at least in the US) the neutral and "earth ground" are common with both directly connected within the breaker panel.
I guess the power company must be sending SMART ELECTRONS down the pipe that will only go to approved loads
Kind of like HDMI. The electron must handshake whth the toaster oven before it can make toast.
No handshake with the direct short so the electrons won't go there |
Handshake for the toaster. Man that is classic. I love it. 
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tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
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| Posted: Mon Jun 07, 2010 11:47 pm Post subject: |
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Connecting the power lines directly to earth ground doesn't make much sense but connecting them to a "protector" (some sort of voltage clamping device) that is connected directly to earth ground would be a good idea.
Scott
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Tue Jun 08, 2010 12:06 am Post subject: |
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| tse wrote: | Connecting the power lines directly to earth ground doesn't make much sense but connecting them to a "protector" (some sort of voltage clamping device) that is connected directly to earth ground would be a good idea.
Scott |
This is what I have been agreeing with all along however it is still not an absolute. Based on the datasheets of the devices he posted they are very limited on there maximum joule rating, which is nowhere even closed to the joule range of an actual lightning bolt. Also in the question I asked about if the house was hit directly then the charge would still have to travel through the house to get to the box device. The datasheet also states the protection is for incoming surges, not reverse surges.
For lesser transient voltages the device would work great. Stating the device as an absolute for a full strike is ridiculous. And the datasheets state so.
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Cube
Joined: 06 Dec 2009
Posts: 77
Location: IL, USA
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| Posted: Tue Jun 08, 2010 12:50 am 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. |
I wasn't making an assumption. The other day I was reading a review of a PSU where they took it apart and noted that it contained a MOV.
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CasetheCorvetteman
Joined: 09 Nov 2008
Posts: 6326
Location: Australia
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| Posted: Tue Jun 08, 2010 10:22 am Post subject: |
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| Cube wrote: | | 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. |
I wasn't making an assumption. The other day I was reading a review of a PSU where they took it apart and noted that it contained a MOV. |
No it certainly didnt seem to me as though you did either, and id say there is a very good chance your observation was correct.
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westom
Joined: 14 Dec 2009
Posts: 56
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| Posted: Tue Jun 08, 2010 1:46 pm Post subject: |
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| Cube wrote: | | The other day I was reading a review of a PSU where they took it apart and noted that it contained a MOV. |
Was it an MOV or an inrush current limiter?
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Cube
Joined: 06 Dec 2009
Posts: 77
Location: IL, USA
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David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
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| Posted: Tue Jun 08, 2010 6:15 pm Post subject: |
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Why would an SMPS have inrush current limiter? Makes no sense.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Tue Jun 08, 2010 6:41 pm Post subject: |
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An inrush current limiter is wired in series with the power line and functions by temperature/resistance, meaning as incoming current increases the thermistor increases in temperatue and resistance then decreases. Resistance is greater when cold allowing limited incoming surge current, then as it heats up will allow normal current flow.
And yes they are used in power supplies.
MOVs connect power to ground and when the rated clamping voltage (surge) is reached it directs power to ground (varistor). Not usually used in power supplies.
Last edited by macgyver655 on Tue Jun 08, 2010 6:58 pm; edited 3 times in total
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Tue Jun 08, 2010 6:43 pm Post subject: |
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Oh, and inrush current limiting is not always limited to just one device. Multiple devices can be used to accomplish its goal.
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David_Web
Joined: 02 May 2007
Posts: 418
Location: Sweden
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| Posted: Tue Jun 08, 2010 8:15 pm Post subject: |
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I just don't see a thermistor as something useful or required in SMPS. 2-5W idle would probably not "trip" a thermistor properly as it charge up the caps and other operating parts. It would just waste lots of electricity if it did.
A big transformer with caps to fill up is another story though.
And if you haven't notices most SMPS draws a short spike of high current when connected or turned on.
At times you can see lights dim, so definitively no current limiting or thermistor.
Depends how big it is and of what quality though.
With active power factor correction and other features I see no reason to use anything else than active current limiting and protection. So no thermistor there ether.
Maybe in old or large SMPS but I have yet to see any.
PPTC is over current protection more than limiting so it won't count ether.
An inductor in series with input would be a good current limiter as far as transients go. And filter out HF noise at the same time.
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macgyver655
Joined: 22 Aug 2007
Posts: 8508
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| Posted: Tue Jun 08, 2010 9:19 pm Post subject: |
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http://en.wikipedia.org/wiki/Inrush_current_limiter
If you do some searching you will find many, many articles on thermistors used for inrush current limiting.
But, as I said, a thermistor is not the only way to handle inrush current but is one option that is widely used.
My answer was directed to your post "Why would an SMPS have inrush current limiter? Makes no sense." and merely to indicate one type of inrush current limiting option. There are many.
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