Al
http://www.apcmedia.com/salestools/SADE ... _R0_EN.pdf
This article pretty much covers the high rise Sony used in the 80s. It shows some of the problems associated today, which also existed twenty years ago. In the hi rise, your choices are limited.
Back then harmonics was worse, but the US still lags behind the international community in changing all the equipment.
Up stairs they use three phase transformers to deliver the wall current.
Transformer blew, and the VCRs suffered from simple harmonics.
Sony alleviated this problem on the 7th floor using multiple neutral and earths conductors, all the way back to the ground floor.
In the air at 70 feet, your choices are restricted, but at ground level the earth is one huge conductor that can be utilized for more simple corrections.
Legal?
I have seen many variations of legal in this state, but as mentioned two safeties are better than one so at best, its not illegal.
Strange AC Power Issue
Hello Al,
In an earlier post you asked:
"So you are saying the ground wire might be open?"
This would be one possible explanation. However, this would not explain the reading of 27v from "metal" to the water pipe. I assume that metal refers to the box containing the circuit breakers or some other junction box. The Code usually requires all metal enclosures to be connected to the fault current system (sometimes called safety ground). This appears to have been done. It was probably done by the manufacturer of the box, since this connection will be required and is wholly enclosed within the box. This connection may be as simple as mounting the ground bus bar directly on the box with no insulation. The green wires from the various branch circuits would also be connected to this bus bar. The white wires (neutrals) would be connected to a second bus bar, which should be insulated from the box. A wire from the grounding system (which may also connect to the water pipe) may have been connnected to the neutral bus bar. This would explain the neutral wires being at the same potential as the water pipe.
The NEC calls for a jumper between the neutral and the fault current system. This appears to be missing. It may have been omitted from the original installation or possibly removed during testing and not reinstalled.
Francesco should get an electrician to examine the wiring to make sure that this is indeed the problem and to make sure that the jumper is properly sized and installed.
In an earlier post you asked:
"So you are saying the ground wire might be open?"
This would be one possible explanation. However, this would not explain the reading of 27v from "metal" to the water pipe. I assume that metal refers to the box containing the circuit breakers or some other junction box. The Code usually requires all metal enclosures to be connected to the fault current system (sometimes called safety ground). This appears to have been done. It was probably done by the manufacturer of the box, since this connection will be required and is wholly enclosed within the box. This connection may be as simple as mounting the ground bus bar directly on the box with no insulation. The green wires from the various branch circuits would also be connected to this bus bar. The white wires (neutrals) would be connected to a second bus bar, which should be insulated from the box. A wire from the grounding system (which may also connect to the water pipe) may have been connnected to the neutral bus bar. This would explain the neutral wires being at the same potential as the water pipe.
The NEC calls for a jumper between the neutral and the fault current system. This appears to be missing. It may have been omitted from the original installation or possibly removed during testing and not reinstalled.
Francesco should get an electrician to examine the wiring to make sure that this is indeed the problem and to make sure that the jumper is properly sized and installed.
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Chris Smith
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The rules are simple, if you haven’t done it personally, you have no overly valuable comments to add. You listen and then you learn.
If you don’t have the experience and you don’t like the answer, keep quiet.
Blow your smoke somewhere else, you wont be winning any cupie dolls here any time soon.
If you don’t have the experience and you don’t like the answer, keep quiet.
Blow your smoke somewhere else, you wont be winning any cupie dolls here any time soon.
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positronicle
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Chris Smith
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- Location: Bieber Ca.
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positronicle
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Chris Smith
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- Joined: Tue Dec 04, 2001 1:01 am
- Location: Bieber Ca.
Im sorry to tell you but you didn’t win the cupie doll.
So far you have gotten them all wrong which makes your post a waste of good space.
Be annoyed some where else, this space Is for learning, not arguing.
You had the chance for a formal education, you chose not to take that opportunity, stop trying to now compare your self with those who did.
Wiring a house for 240 is one experience that hardly makes mention. I did that in the 80s, with my eyes closed.
If you don’t have the experience and you don’t like the answer, keep quiet.
Your like a fish on the hook, but you keep wiggling out of water any way.
You wont win any prizes, but you can keep sinking your foot deeper and deeper, I wont stop you.
So far you have gotten them all wrong which makes your post a waste of good space.
Be annoyed some where else, this space Is for learning, not arguing.
You had the chance for a formal education, you chose not to take that opportunity, stop trying to now compare your self with those who did.
Wiring a house for 240 is one experience that hardly makes mention. I did that in the 80s, with my eyes closed.
If you don’t have the experience and you don’t like the answer, keep quiet.
Your like a fish on the hook, but you keep wiggling out of water any way.
You wont win any prizes, but you can keep sinking your foot deeper and deeper, I wont stop you.
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Robert Reed
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- Contact:
"You had the chance for a formal education, you chose not to take that opportunity, stop trying to now compare your self with those who did."
You repeatedly Mention that people on this forum get a formal education. If you truly believe what you are saying, why don't you get one for yourself? As with most these drawn out posts, they seem to center around you. One post in particular about a year ago that involved a poster by the name of JARHEAD comes to mind. You attacked eveyone for not having your level of education, yet when you were queried on this subject you evaded it like a smooth politician. Everyone on the post not only gave their education history but also their professional status, and some were quite impressive- i,e, Jarhead- senior avionics engineer for a major aircraft company, just to name one.
"Wiring a house for 240 is one experience that hardly makes mention. I did that in the 80s, with my eyes closed."
That has been quite apparent from your postings.
You repeatedly Mention that people on this forum get a formal education. If you truly believe what you are saying, why don't you get one for yourself? As with most these drawn out posts, they seem to center around you. One post in particular about a year ago that involved a poster by the name of JARHEAD comes to mind. You attacked eveyone for not having your level of education, yet when you were queried on this subject you evaded it like a smooth politician. Everyone on the post not only gave their education history but also their professional status, and some were quite impressive- i,e, Jarhead- senior avionics engineer for a major aircraft company, just to name one.
"Wiring a house for 240 is one experience that hardly makes mention. I did that in the 80s, with my eyes closed."
That has been quite apparent from your postings.
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Chris Smith
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Robert Reed
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Chris Smith
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- Location: Bieber Ca.
Ask the president, Im sure he will say you won.
Nothing else will even come close.
And remember...Don’t give your opinion like it was an educated fact.
Its real simple, the only way you get to change history is when you invent the time machine.
Till that day comes, sit on the back burner, your opinion here is moot.
Nothing else will even come close.
And remember...Don’t give your opinion like it was an educated fact.
Its real simple, the only way you get to change history is when you invent the time machine.
Till that day comes, sit on the back burner, your opinion here is moot.
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Chris Smith
- Posts: 4325
- Joined: Tue Dec 04, 2001 1:01 am
- Location: Bieber Ca.
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