Square D electrical panel question

On Thursday, March 10, 2016 at 9:02:12 AM UTC-5, Mr Macaw wrote:

IDK what you're talking about now. For starters, circuit breakers don't trip when you touch live and earth, unless it is a GFCI breaker, which are the less common type and only required in certain applications. Second, per Ohms law, the higher the voltage in a given circuit, the higher the current. A human body, together with the rest of the circuit that completes it, has some resistance value. With a higher voltage, you will have higher current flowing, ergo it's easier to get to your 30ma.
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Of course that's the type I'm talking about, hence me referring to 30mA, not 15A. In the UK, the whole house is protected by such things, why wouldn't it be? This is why I use fuses.

My point is both voltages will easily exceed 30mA. If they didn't, those GFCI breakers would never trip. Killing you with 120mA is no worse than killing you with 60mA.
I just measured my resistance from hand to hand (the most likely path to get through the heart). 50kohm with wet hands, 500kohm with dry hands. At 120V, that's 2mA wet and 0.2mA dry. At 240V, that's 5mA wet and 0.5mA dry. No wonder I've never stopped my heart. It's impossible. The body has way more resistance than I thought. And I was squeezing as hard as I could for a good contact.
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On Thursday, March 10, 2016 at 9:21:20 AM UTC-5, Mr Macaw wrote:
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it can kill you? Anything over 80 volts or something like that is all the same.

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ng it higher than enough to kill you doesn't matter.

s 30mA with either voltage. Why do you think circuit breakers manage to tr ip when you touch live and earth? They need 30mA to trip.

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not 15A. In the UK, the whole house is protected by such things, why would n't it be? This is why I use fuses.

If you're using fuses, why are you talking about GFCI? Of all the circuit breakers in the world, only a small fraction are GFCI.

As stated previously, it depends on the resistance of the entire circuit, including human body. Will it exceed 30ma in most cases, whether it's 120V or 240V, probably. But that doesn't change the fact that more current will flow at 240V than at 120V. Where with one you could have 30ma, with the other you could have 60ma and the higher it is, the worse it is. Capiche?

120mA is no worse than killing you with 60mA.
Why do you keep going back to GFCI all the time?

get through the heart). 50kohm with wet hands, 500kohm with dry hands. At 120V, that's 2mA wet and 0.2mA dry. At 240V, that's 5mA wet and 0.5mA dry . No wonder I've never stopped my heart. It's impossible. The body has w ay more resistance than I thought. And I was squeezing as hard as I could for a good contact.

Following that faulty logic, no one would ever be electrocuted by 120V, 240V, etc. There would be no need for GFCI. Yet it happens all the time.
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I'm using fuses but most people here use GFCI. All breakers are GFCI, or if you're a cheapskate, you have a GFCI or two master breaker which cuts off all the others. Why invent a "life saving" device then only use it here and there?

No, as you stated 30mA would kill you. Dying twice is no worse than dying once.

Because they prove that 30mA is attainable by touching live and ground with your body.

No it doesn't. You need a very weak heart to die, most hearts will restart automatically as soon as the power is removed. And I'm not convinced about the 30mA, perhaps with a weak heart you can die with a few mA, or people manage to get power going into their chest and not their hands.
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You folks are talking apples, oranges and pomegranates
In UK, Oz and NZ they have an RCD that looks for ground faults in the range of 30ma and disconnect the whole panel. This is a typical NZ panel. The red breaker is the main, the blue the RCD and the rest are branch circuit breakers.
In the US we only protect single branch circuits or individual loads with a GFCI but that is at 5ma. When we see 30ma protection, it is called "ground fault protection for equipment" because we think 30ma is too high to protect people. One thing you must keep in mind is 5ma might not kill you but it can still cause you to fall off the ladder.
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On Thu, 10 Mar 2016 11:08:30 -0500, snipped-for-privacy@aol.com wrote:
Forgot the picture

http://gfretwell.com/ftp/New%20Zealand/Wangatui/Panel%20board.jpg

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The ones I've seen don't have the superfluous red one. The blue one is used to switch everything off, aswell as interrupt if there's 30mA to earth. They've started putting in more than one blue one, hence you don't cut the whole house off when someone gets a shock, eg. you don't get put in the dark when you get a shock.
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Forgot to mention, non-cheapskates get combined current limit breakers and earth leakage breakers, so every circuit has its own protection for both.
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I see, so you're being way too safe again. Bunch of pansies is what you are. When we put in RCDs at 30mA, it was advertised you wouldn't even feel it when you touched the live. I touched a live wire on my mower without any breaker on it (a rat had chewed the flex) and had my bare feet on the ground. I jumped SLIGHTLY and said "Ayabastard!" Having that on a trip would have reduced it to un-noticeable..
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You can get your bell rung pretty good at 30ma. Even the 5ma will wake you up.
I do think you should go easy on the "pansy" talk tho. 300,000,000-400,000,000 million guns don't seem to scare us much and well over a million are even machine guns.
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Not for a very short period of time, which is all the breaker allows.

You have guns BECAUSE you're scared.
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We have guns because we can. The thing a lot of people do not understand is there is a very active shooting sport community here. Beyond hunting we also have skeet, trap, sporting clays and a number of different target sports. That is where most of the billions of rounds of ammo that get fired here are used. It is just not worthy of putting on CNN.
This is simply another country with another culture. You are 3000 miles away, I think you will be safe if you stay there.
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I see, so you're being way too safe again. Bunch of pansies is what you are. When we put in RCDs at 30mA, it was advertised you wouldn't even feel it when you touched the live. I touched a live wire on my mower without any breaker on it (a rat had chewed the flex) and had my bare feet on the ground. I jumped SLIGHTLY and said "Ayabastard!" Having that on a trip would have reduced it to un-noticeable..
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On Thursday, March 10, 2016 at 11:08:44 AM UTC-5, snipped-for-privacy@aol.com wrote:

And McCaw doesn't understand Ohms law either.
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Show me some evidence as to why you think I don't. I have a degree in electronics and I can assure you I know everything there is to know about resistance.
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wrote:

Something to do with the physiological responce to the shock. Some voltages make you hang on, others throw you off - making it virtually impossible to hold on.. I can't remember what my Dad used to say (he was an electrician) but some of the higher voltages could be safer than the lower voltages because the lower voltage made you grab the wire hard and not let go.
The let-go phenomenon for low (<600 V) contact
A factor that makes a large difference in the injury sustained in low-voltage shocks is the inability to let go. The amount of current in the arm that will cause the hand to involuntarily grip strongly is referred to as the let-go current.7 If a person's fingers are wrapped around a large cable or energized vacuum cleaner handle, for example, most adults will be able to let go with a current of less than 6 mA. At 22 mA, more than 99% of adults will not be able to let go. The pain associated with the let-go current is so severe that young, motivated volunteers could tolerate it for only a few seconds.7 With current flow in the forearm, the muscles of flexion and extension are both stimulated. However, the muscles of flexion are stronger, making the person unable to voluntarily let go. Nearly all cases of inability to let go involve alternating current. Alternating current repetitively stimulates nerves and muscles, resulting in a tetanic (sustained) contraction that lasts as long as the contact is continued. If this leads to the subject tightening his or her grip on a conductor, the result is continued electric current flow through the person and lowered contact resistance.8
With alternating current, there is a feeling of electric shock as long as contact is made. In contrast, with direct current, there is only a feeling of shock when the circuit is made or broken. While the contact is maintained, there is no sensation of shock. Below 300 mA DC rms, there is no let-go phenomenon because the hand is not involuntarily clamped. There is a feeling of warmth while the current travels through the arm. Making or breaking the circuit leads to painful unpleasant shocks. Above 300 mA, letting go may be impossible.4 The threshold for ventricular fibrillation for direct current shocks longer than 2 seconds is 150 mA as compared with 50 mA for 60-Hz shocks; for shocks shorter than 0.2 seconds, the threshold is the same as that for 60-HZ shocks, that is, approximately 500 mA.4
Heating power is also increased when a person cannot let go. This is because a firm grip increases the area of skin effectively in contact with the conductors. Additionally, highly conductive sweat accumulates between the skin and conductors over time. Both of these factors lower the contact resistance, which increases the amount of current flow. In addition, the heating is greater because the duration of the contact is often several minutes in comparison with the fraction of a second that it takes to withdraw from a painful stimulus.
Being unable to let go results in more current for a longer period of time. This will increase damage due to heating of muscle and nerves. There will also be an increase in pain and the incidence of respiratory and cardiac arrest. There can also be shoulder dislocation with associated tendon and ligament injury, as well as bony fractures in the area of the shoulders.
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The let-go phenomenon for high (>600 V) contact
Several different outcomes may occur when a person grasps a conductor giving 10 kV AC hand-to-hand voltage. It takes over 0.5 seconds of such contact before most of the distal forearm cells are heat damaged. However, within 10 to 100 milliseconds, muscles in the current path will strongly contract. The person may be stimulated to grasp the conductor more tightly, making a stronger mechanical contact. Or, the person may be propelled away from the contact. Which of these events occurs depends on the position of the hand relative to the conductor. Most eyewitnesses report the victims being propelled from the conductor, possibly because of generalized muscle contractions. The time of contact is estimated to be about 100 milliseconds or less in such cases.9(p57
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I thought all AC allowed you to let go? DC cramps your muscles up.

I call "bollocks". I once picked up a wall socket which I'd used as a trailing socket, and it was wired backwards (earlier on, not by me), so when I'd switched it off, I'd disconnected the neutral and not the live. Hence I got 240V through my hand from live to earth. All it did was warm up my hand. I let go very easily.

Incorrect again. Place a PP3 9V battery on your tongue. That will sting continuously until you remove it.
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On Sunday, March 6, 2016 at 6:01:32 PM UTC-5, Mr Macaw wrote:

ailing socket, and it was wired backwards (earlier on, not by me), so when I'd switched it off, I'd disconnected the neutral and not the live. Hence I got 240V through my hand from live to earth. All it did was warm up my h and. I let go very easily.

It also doesn't make sense as written. Volunteers could only tolerate it f or a few seconds? How long does it take to let go?

continuously until you remove it.

Agree, been there, done that too.
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Back to the main panel disconnect question.
My house always had the meter outside and the main panel inside, with the main disconnect on the panel.
When an upgrade was done to the main panel, an extra breaker was added outside just below the meter. The electrician said this was a code requirement, because wire between the meter and the panel needed to be protected because of the location.
Did this new breaker now become the service disconnect? And if so, is the main panel now noncompliant for having ground and neutral bonded?
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wrote:

Yes they should have pulled in a 4 wire feeder and separated the neutral and ground. The issue of how far the SE is running inside the house before it needs protection is really undefined. Inspectors in the same jurisdictions may even disagree. On one extreme some say a few feet, as directly it can be run, using SE cable, is just fine. Others say they want a back to back installation with the wire simply passing through the wall in a short pipe nipple. The most extreme interpretation pretty much wants an outside disconnect no matter what.
This is the code 230.70(A)(1) Readily Accessible Location. The service disconnecting means shall be installed at a readily accessible location either outside of a building or structure or inside nearest the point of entrance of the service conductors.
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