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#1431 - 05/10/01 04:37 PM proofreader needed
klim Offline
Junior Member

Registered: 05/10/01
Posts: 4
Loc: Livermore CO USA
I am in the final stages of writing a book titled The Horse Barn. A portion of the book (8,000 words) relates to electrical design and installation.

I am looking for a qualified electrician to check the electrical portion of my manuscript for accuracy, especially concerning safety and legal issues. There would be no monetary compensation, but I will acknowledge the reader in the book.

If anyone is interested or can recommend someone, please contact me at rklimesh@horsekeeping.com. Thank you.

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#1432 - 05/10/01 05:47 PM Re: proofreader needed
Anonymous
Unregistered


Would you mind posting a couple of paragraphs to give an idea of how this reads at present?

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#1433 - 05/10/01 06:01 PM Re: proofreader needed
klim Offline
Junior Member

Registered: 05/10/01
Posts: 4
Loc: Livermore CO USA
Sure. Here's an exerpt.
Electricity from the local utility company is typically supplied through three overhead or underground wires called service conductors. An electric service or feed consists of two "hot" leads (wires) each carrying 120 volts, and one "neutral" lead. Two hot leads are used together to provide 240 volts when needed. The wires pass through a meter and into the service panel of the building where they connect to metal strips called buss bars (9.1). The neutral wire and another "safety ground" or "green" wire (often bare copper) connect from the service panel to a copper rod driven into the earth. Three wires, hot, neutral, and safety ground make up the connections found in a typical outlet receptacle.
You may wonder why both the safety ground wire and neutral are needed since both ultimately connect to the same ground rod. Actually, the safety ground wire isn't needed as evidenced by the large number of electrical appliances which only use only two (hot and neutral) prongs. But, in electrical equipment which has a safety ground connection (a three pronged plug), the round grounding prong is always connected to any exposed metal parts of the equipment. That way, if an exposed part of the equipment becomes energized due to a wiring fault inside the equipment the safety ground connection causes the hot connection to be directly connected to earth, and the fuse or circuit breaker would shut down power to the circuit. Equipment with two-prong plugs usually has a non-conducting plastic case so errant electricity cannot pass to a person or horse touching the case.

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#1434 - 05/10/01 08:01 PM Re: proofreader needed
sparky66wv Offline
Member

Registered: 11/17/00
Posts: 2339
Loc: West Virginia
 Quote:
safety ground


I like that!

That's the perfect name/description for the equipment grounding conductor, much more intuitive! Bravo... You sure you need our help? You're off to a great start there!
_________________________
-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

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#1435 - 05/10/01 08:06 PM Re: proofreader needed
klim Offline
Junior Member

Registered: 05/10/01
Posts: 4
Loc: Livermore CO USA
Thanks for the kind words. It's good to know I'm on the right track. Since I'm not an electrician, I want to run the info by a professional to make sure I don't mislead readers.

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#1436 - 05/10/01 08:52 PM Re: proofreader needed
Anonymous
Unregistered


I can see that you wouldn't want me editing it!


Electricity from the local utility company is typically supplied through three or four overhead or underground wires called service conductors.
Sure they run a lot of overhead triplex on a farm. But if you don't want your animals experiencing stray voltage, four are better.

An electric service or feed consists of two "hot" leads (prounounced >leedz< ) (wires) each providing 120 volts, and one "neutral" lead. Two hot leads - which are out of phase to each other - are used together to provide 240 volts where needed. The wires pass through a meter box and into the service panel of the building where they connect to metal strips called buss bars (9.1).

(In some cases, the farm exception, the meter is on a pole and the service splits to the house and barn from there.)

A "safety ground" or "green" wire (often bare copper) connects from the service panel to copper rods (electrodes) driven 8' into the earth.
The neutral wire from the utility is also tied to the safety ground.

Three wires: one hot, a neutral, and a safety ground make up the connections to in a typical outlet receptacle.

You may wonder why both the safety ground wire and neutral are needed since both ultimately connect to the utility's neutral.

The safety ground wire isn't always needed as evidenced by the large number of electrical appliances which only use only two (hot and neutral) prongs. But, in electrical equipment which has a safety ground connection (a three pronged plug), the round grounding prong is always connected to any exposed metal parts of the equipment. That way, if an exposed part of the equipment becomes energized by wiring fault (failure) inside the equipment the safety ground connection causes the hot connection to short circuit without having to follow an unanticipated and potentially lethal path, and the fuse or circuit breaker should shut down power to the circuit.

Equipment with two-prong plugs usually has a non-conducting plastic case so errant electricity should not pass to a person or horse touching the case.

Sorry, I won't do the rest free.

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#1437 - 05/10/01 09:25 PM Re: proofreader needed
Matt M Offline
Member

Registered: 03/25/01
Posts: 93
Loc: Laporte, MN, USA
"An electric service or feed consists of two "hot" leads (prounounced >leedz< ) (wires) each providing 120 volts, and one "neutral" lead. Two hot leads - which are out of phase to each other - are used together to provide 240 volts where needed."

Huh? Out of phase? But isn't this single phase? I like this description much better.

A single phase, AC service drop consists of two ungrounded (hot) conductors, with a potential difference of 240 volts nominal between them, and a grounded (neutral) conductor with a potential difference of 120 volts nominal between it and either one of the two ungrounded conductors.

I also have a little trouble with the word "carry" with regard to voltage. I think a more accurate term would be "supply". The conductors are not really carrying voltage, they are carrying an amount of electricity that is measured in amperes that are being supplied or propelled by voltage (electrical pressure).

If we use the old water analogy here with regard to a water hose, the voltage would be compared to the water pressure, and the amperes would be compared to the volume of water in the hose. Using this logic, we could make the statement that "X" PSI of water pressure is supplying the water hose with "Y" gallons of water. The hose does not carry pressure, but rather it carries water, that is being supplied by pressure.

Also, when referring to a nominal voltage such as 120, you cannot really say that an individual conductor supplies 120 volts, it must have another conductor of which to compare this potential difference. For example, "Either one of the ungrounded (hot) conductors has a potential difference of 120 volts between itself, and the neutral conductor". It may have a potential difference of 120 volts to earth ground, but it is also true that it could have a potential difference of 50,000 volts to a passing thundercloud.

Matt



[This message has been edited by Matt M (edited 05-11-2001).]

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#1438 - 05/10/01 09:39 PM Re: proofreader needed
sparky66wv Offline
Member

Registered: 11/17/00
Posts: 2339
Loc: West Virginia
_________________________
-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

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#1439 - 05/10/01 10:04 PM Re: proofreader needed
Steve T Offline
Member

Registered: 02/14/01
Posts: 312
Loc: Oak Park, IL, USA
The two hot conductors are typically 180 degrees out of phase. This is why you get 240 between the two hots and 120 from each hot to ground. If you got 120v from each hot to ground and 120 from hot to hot it wouldn't make much sense to have a three wire system. There are still a lot of two wire systems which are referred to as single phase--single phase, two wire. On this system, one wire is hot and one is grounded.

As far as the descriptions for the book, as long as you make mention that this is not an electrical training maual and that anyone who is not qualified should seek the skills of a professional electrician, your description is fine.

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#1440 - 05/10/01 10:10 PM Re: proofreader needed
sparky66wv Offline
Member

Registered: 11/17/00
Posts: 2339
Loc: West Virginia
If they were 180 degrees out of phase, you would have nothing.

Sorry to burst your bubble..

Where's Scott? Hmmm, how would he handle this...



The reality is that the secondary coil in the transformer is center tapped to neutral (grounded conductor) in a 240V single phase system... the center tap splits up the two 120V legs.

Notice that the transformer outside your home is tapped to only one ungrounded high voltage conductor, hence single phase.

First, technically, there is no neutral in a single phase system. The white (or natural grey) wire is called the "grounded conductor". This is not to be confused with the "ground" (green or bare wire) which is called the "equipment grounding conductor".

In a 120/240 Volt Single Phase system, the transformer secondary coil is "center tapped" to ground which defines the grounding conductor's voltage as "zero". The right and left extremes of the secondary coil are the taps for each 120 Volt leg. Voltage from either the right or left tap to the grounded center tap will be 120 Volts or thereabouts. But the voltage between the left and right taps are 240 Volts, not involving the grounded conductor at all.


[This message has been edited by sparky66wv (edited 05-11-2001).]
_________________________
-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

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