Aircraft Design Weight and Balance Handbook Ch. 2a

Weight and Balance Theory

Two elements are vital in the weight and balance considerations of an aircraft:

• The total weight of the aircraft must be no greater than the maximum gross weight allowed by the FAA for the particular make and model of the aircraft.
• The center of gravity, or the point at which all of the weight of the aircraft is considered to be concentrated, must be maintained within the allowable range for the operational weight of the aircraft.

Aircraft Arms, Weights, and Moments

The term arm, usually measured in inches, refers to the distance between the center of gravity of an item or object and the reference datum. Arms ahead of, or to the left of the datum are negative (–), and those behind, or to the right of the datum are positive (+). When the datum is ahead of the aircraft, all of the arms are positive and computational errors are minimized.

Weight is normally measured in pounds. When weight is removed from an aircraft, it is negative (–), and when added, it is positive (+).

There are a number of weights that must be considered in aircraft weight and balance. The following are terms for various weights as used by the General Aviation Manufacturers Association (GAMA).

• The standard empty weight is the weight of the airframe, engines and all items of operating weight that have fixed locations and are permanently installed in the aircraft. This weight must be recorded in the aircraft weight and balance records. The basic empty weight includes the standard empty weight plus any optional equipment that has been installed.
• Maximum allowable gross weight is the maximum weight authorized for the aircraft and all of its contents as specified in the Type Certificate Data Sheets (TCDS) or Aircraft Specifications for the aircraft.
• Maximum landing weight is the greatest weight that an aircraft normally is allowed to have when it lands.
• Maximum takeoff weight is the maximum allowable weight at the start of the takeoff run.
• Maximum ramp weight is the total weight of a loaded aircraft, and includes all fuel. It is greater than the takeoff weight due to the fuel that will be burned during the taxi and run up operations. Ramp weight is also called taxi weight.

The manufacturer establishes the allowable gross weight and the range allowed for the CG, as measured in inches from a reference plane called the datum. In large aircraft, this range is measured in percentage of the mean aerodynamic chord (MAC), the leading edge of which is located a specified distance from the datum.
The datum may be located anywhere the manufacturer chooses; it is often the leading edge of the wing or some specific distance from an easily identified location. One popular location for the datum is a specified distance forward of the aircraft, measured in inches from some point such as the leading edge of the wing or the engine firewall.

The datum of some helicopters is the center of the rotor mast, but this location causes some arms to be positive and others negative. To simplify weight and balance computations, most modern helicopters, like airplanes, have the datum located at the nose of the aircraft or a specified distance ahead of it.
A moment is a force that tries to cause rotation, and is the product of the arm, in inches, and the weight, in pounds. Moments are generally expressed in pound-inches (lb-in) and may be either positive or negative. Figure 2-1 shows the way the algebraic sign of a moment is derived. Positive moments cause an airplane to nose up, while negative moments cause it to nose down.
figure 2-1

The Law of the Lever

All weight and balance problems are based on the physical law of the lever. This law states that a lever is balanced when the weight on one side of the fulcrum multiplied by its arm is equal to the weight on the opposite side multiplied by its arm. In other words, the lever is balanced when the algebraic sum of the moments about the fulcrum is zero. [Figure 2-2] This is the condition in which the positive moments (those that try to rotate the lever clockwise) are equal to the negative moments (those that try to rotate it counter- clockwise).

figure 2-2

Consider these facts about the lever in Figure 2-2: The 100-pound weight A is located 50 inches to the left of the fulcrum (the datum, in this instance), and it has a moment of 100°?–50 = –5,000 lb-in. The 200-pound weight B is located 25 inches to the right of the fulcrum, and its moment is 200° +25 = +5,000 lb-in. The sum of the moments is –5,000 +5,000 = 0, and the lever is balanced. [Figure 2-3] The forces that try to rotate it clockwise have the same magnitude as those that try to rotate it counterclockwise.
figure 2-3

Determining the CG
One of the easiest ways to understand weight and balance is to consider a board with weights placed at various locations. We can determine the CG of the board and observe the way the CG changes as the weights are moved. The CG of a board like the one in Figure 2-4 may be deter-mined by using these four steps:

1. Measure the arm of each weight in inches from a datum.
2. Multiply each arm by its weight in pounds to determine the moment in pound-inches of each weight.
3. Determine the total of all the weights and of all the moments. Disregard the weight of the board.
4. Divide the total moment by the total weight to determine the CG in inches from the datum.

figure 2-4

In Figure 2-4, the board has three weights, and the datum is located 50 inches to the left of the CG of weight A. Determine the CG by making a chart like the one in Figure 2-5.

figure 2-5

As noted in Figure 2-5, “A” weighs 100 pounds and is 50 inches from the datum; “B” weighs 100 pounds and is 90 inches from the datum; “C” weighs 200 pounds and is 150 inches from the datum. Thus the total of the three weights is 400 pounds, and the total moment is 44,000 lb-in. Determine the CG by dividing the total moment by the total weight.

script...

To prove this is the correct CG, move the datum to a location 110 inches to the right of the original datum and determine the arm of each weight from this new datum, as in Figure 2-6. Then make a new chart similar to the one in Figure 2- 7. If the CG is correct, the sum of the moments will be zero.

figure 2-6

The new arm of weight A is 110 – 50 = 60 inches, and since this weight is to the left of the datum, its arm is negative, or –60 inches. The new arm of weight B is 110 – 90 = 20 inches, and it is also to the left of the datum, so it is –20; the new arm of weight C is 150 – 110 = 40 inches. It is to the right of the datum and is therefore positive.

figure 2-7

The location of the datum used for determining the arms of the weights is not important; it can be anywhere. But all of the measurements must be made from the same datum location.

Determining the CG of an airplane is done in the same way as determining the CG of the board in the example on the previous page. [Figure 2-8] Prepare the airplane for weighing (as explained in Chapter 3) and place it on three scales. All tare weight, the weight of any chocks or devices used to hold the aircraft on the scales, is subtracted from the scale reading, and the net weight of the wheels is entered into a chart like the one in Figure 2-9. The arms of the weighing points are specified in the TCDS for the airplane in terms of stations, which are distances in inches from the datum.

figure 2-8 figure 2-9


The empty weight of this aircraft is 5,862 pounds. Its EWCG, determined by dividing the total moment by the total weight, is located at fuselage station 201.1. This is 201.1 inches behind the datum.
script 2...

Copyright Basics

This chapter is an introduction to some basic copyright concepts and vocabulary. It is designed to pave the way for more detailed discussions in later chapters. We therefore urge you not to use this material to reach a final conclusion about any particular issue. Only after reading one or more of the later chapters will you be in a position to make a judgment about a particular question or course of action.

Why Have a Copyright Law?

The Founding Fathers recognized that everyone would benefit if creative people were encouraged to create new intellectual and artistic works. When the United States Constitution was written in 1787, the framers took care to include a copyright clause (Article I, Section 8) stating that "The Congress shall have Power … To promote the Progress of Science and useful Arts, by securing for limited times to Authors … the exclusive Right to their … writings."

The primary purpose of copyright, then, is not to enrich authors; rather, it is to promote the progress of science and the useful arts—that is, human knowledge. To pursue this goal, copyright encourages authors in their creative efforts by giving them a mini-monopoly over their works—termed a copyright. But this monopoly is limited when it appears to conflict with the overriding public interest in encouraging creation of new intellectual and artistic works generally. (See Section E, below.)

What Is Copyright?

Copyright is a legal device that provides the creator of a work of art or literature, or a work that conveys information or ideas, the right to control how the work is used. The Copyright Act of 1976—the federal law providing for copyright protection—grants authors a bundle of intangible, exclusive rights over their work. These rights include:

• reproduction right—the right to make copies of a protected work
• distribution right—the right to sell or otherwise distribute copies to the public
• right to create adaptations (or derivative works)—the right to prepare new works based on the protected work, and
• performance and display rights—the right to perform a protected work such as a stage play, or display a work in public.

An author's copyright rights may be exercised only by the author—or by a person or entity to whom the author has transferred all or part of her rights. If someone wrongfully uses the material covered by the copyright, the copyright owner can sue and obtain compensation for any losses suffered.

In this sense, a copyright is a type of property—it belongs to its owner (usually the author) and the courts can be asked to intervene if anyone uses it without permission. And, like other forms of property, a copyright may be sold by its owner, or otherwise exploited for her economic benefit.

How Is a Copyright Created and Protected?

A copyright automatically comes into existence the moment an author fixes her words in some tangible form—for instance, the moment a book or article is typed, handwritten or dictated. No further action need be taken. However, it is wise to place a valid copyright notice on all published works and to register these works in the U.S. Copyright Office shortly after publication.

What Constitutes Publication

Knowing whether a work has been published or not can be important because many important copyright rules differ for published and unpublished works. A work is published for copyright purposes when copies are sold, rented, lent, given away or otherwise distributed to the public by the copyright owner or by others acting with the owner's permission—for example, a publisher. It is not necessary to sell thousands of copies of a work for it to be considered published. So long as copies of a work are made available to the public, the work is "published" for copyright purposes even if no copies are actually sold or otherwise distributed.

1. Notice

In the past, all published works had to contain a copyright notice (the © symbol followed by the publication date and copyright owner's name) to be protected by copyright. This is no longer true. Use of copyright notices is now optional. Even so, it is always a good idea to include a copyright notice on all published works so that potential copiers will be informed of the underlying claim to copyright ownership.

2. Registration

Prompt registration in the U.S. Copyright Office makes your copyright a matter of public record and provides a number of important advantages if it is ever necessary to go to court to enforce it. To register a work you must fill out a registration form and deposit copies of your work with the Copyright Office.

What Copyright Protects

Copyright protects an author's words if and to the extent they are original—that is, not copied from other authors' works. Since the main goal of copyright is to encourage creation of new intellectual and artistic works, it follows that copyright protection extends only to material authors write themselves.

There is also no reason to protect works whose creation is a purely mechanical or clerical act. Protecting works such as phone books or certain blank forms would not help develop the arts and sciences. An author must employ a minimal amount of creativity in creating the work. This does not mean that to be protectible a work has to be a great work of art, but a minimal amount of thought or judgment must have been involved in its creation.

A work need not be entirely new to be protectible. Copyright protects new material an author adds to a previously existing work. For example, copyright protects derivative works. A derivative work is a work that is created by adapting or transforming previously written material into a new work of authorship. Examples include a screenplay or stage play based on a novel, an English translation of a work written in a foreign language and condensed versions of articles (such as those found in Reader's Digest). Copyright can also protect "compilations." These are works in which preexisting materials are selected, coordinated and arranged so that a new work of authorship is created—for example, anthologies or catalogs.

Limitations on Copyright Protection

We've seen that the purpose of copyright is to encourage intellectual and artistic creation. Paradoxically, giving authors too much copyright protection could inhibit rather than enhance creative growth. To avoid this, some important limitations on copyright protection have been developed.

1. Ideas and Facts Are Not Protected

Copyright only protects the words with which a writer expressed facts and ideas. Copyright does not protect the facts or ideas themselves; facts and ideas are free for anyone to use. To give an author a monopoly over the facts and ideas contained in his work would hinder intellectual and artistic progress, not encourage it. For example, imagine how scientific progress would have suffered if Charles Darwin could have prevented anyone else from writing about evolution after he published The Origin of Species.

Because copyright only extends its protection to words rather than the underlying facts and ideas, works in which the particular words used by the author are important and distinctive—such as poems, novels and plays—enjoy the most copyright protection. Works that readers buy primarily for the ideas and facts they contain, not their language, receive less protection. This includes most types of factual works, such as histories, biographies, how-to books, news stories and so forth.

2. Fair Use

To foster the advancement of the arts and sciences, there must be a free flow of information and ideas. If no one could quote from a protected work without the author's permission (which could be withheld or given only upon payment of a permission fee), the free flow of ideas would be stopped dead. To avoid this, a special fair use exception to authors' copyright rights was created. An author is free to copy from a protected work for purposes such as criticism, news reporting, teaching or research so long as the value of the copyrighted work is not diminished.

3. Works in the Public Domain

Any work that is not protected by copyright is said to be in the public domain. This includes works in which the copyright was lost, works in which the copyright expired and works authored or owned by the federal government. Public domain means what it says—such works belong to the public as a whole. Anyone is free to use them any way she wishes without asking anyone's permission. And no one can ever obtain copyright protection for public domain material, no matter how she transforms it. Everything published in the United States before 1923 is now in the public domain, freely available to us all.

Copyright Ownership and Transfer of Ownership

The copyright in a protectible work is initially owned by the work's author or authors. But a person need not actually create the work to be its "author" for copyright purposes. A protectible work written by an employee as part of her job is initially owned by the employer—that is, the employer is considered to be the work's author. Such works are called works made for hire. Works created by nonemployees who sign work-for-hire agreements may also be works made for hire.

Like any other property, a copyright can be bought and sold. This is the way authors other than self-publishers profit from their work. Typically, authors sell their work to publishers for a fee or royalty. However, transfers of copyright ownership are unique in one respect: Authors or their heirs have the right to terminate any transfer of copyright ownership 35 years after it is made.

How Long a Copyright Lasts

Few things in this world last as long as copyright protection. Indeed, an author's work is likely to be long forgotten before her copyright in it expires. The copyright in works created after 1977 by individuals usually lasts for the life of the author plus an additional 70 years. The copyright in works created by employees for their employers lasts for 95 years from the date of publication, or 120 years from the date of creation, whichever occurs first.

The copyright in works created and published during 1923-1963 lasts for 95 years from the date of publication if they were timely renewed. It may be necessary to do some legwork to determine if a renewal was filed for a work. The copyright in works published during 1964-1977 lasts for 95 years regardless of whether a renewal was filed. The copyright in works created but not published before 1978 lasts at least until 70 years after the author dies.

Copyright Infringement

Copyright infringement occurs when a person other than the copyright owner exploits one or more of the copyright owner's exclusive rights without the owner's permission. This type of theft is also commonly termed copyright piracy.

The Copyright Act doesn't prevent copyright infringement from occurring, just as the laws against auto theft do not prevent cars from being stolen. However, the Copyright Act does give authors a legal remedy to use after an infringement has occurred—they may sue the infringer in federal court.

An author who wins an infringement suit can stop any further infringement, get infringing copies destroyed, obtain damages from the infringer—often the amount of any profits obtained from the infringement—and recover other monetary losses. This means in effect that an author can make a copyright pirate restore the author to the same economic position she would have been in had the infringement never occurred. And, in some cases, the copyright owner may even be able to obtain monetary penalties that may far exceed her actual losses.

Other Protections for Intellectual Property

The copyright law is not the only means available to protect products of human intellect that have some economic value. The state and federal trademark laws protect distinctive words, phrases, logos and other symbols that are used to identify products and services in the marketplace. The federal patent law protects new inventions. State trade secret laws may protect novel and generally unknown ideas, processes or technical designs that provide a commercial advantage in the marketplace.

1. Trademarks

The copyright laws do not protect names, titles or short phrases. This is where trademark protection comes in. Under both federal and state laws a manufacturer, merchant or group associated with a product or service can obtain protection for a word, phrase, logo or other symbol used to distinguish that product or service from others. If a competitor uses a protected trademark, the trademark holder can obtain a court injunction and monetary damages.

EXAMPLE: The word "Kleenex" is a registered trademark of the Kimberly-Clark Corporation. None of Kimberly-Clark's competitors can use this word on a box of facial tissues without Kimberly-Clark's consent. If they do, Kimberly-Clark could get a court to order them to stop and could sue for damages.

The trademark laws are often used in conjunction with the copyright law to protect advertising copy. The trademark laws protect the product or service name and any slogans used in the advertising and the copyright laws protect any additional literal expression that the ad contains.

2. Patents

By filing for and obtaining a patent from the U.S. Patent and Trademark Office, an inventor is granted a monopoly on the use and commercial exploitation of her invention for a limited time. A patent may protect the functional features of a machine, process, manufactured item, method of doing business, composition of matter, ornamental design or asexually reproduced plants. A patent also protects new uses for any such items. However, to obtain a patent, the invention must be novel and non-obvious.

EXAMPLE: Mickey invents an entirely new and non-obvious type of mousetrap. He applies for a patent on his invention. If and when it's issued, no one can make, use or sell Mickey's invention without his permission for the term of the patent (20 years from the date the patent application was filed). If they do, Mickey can sue them for patent infringement.

The basic difference between a patent and a copyright is that a patent protects ideas as expressed in an invention, whether a machine or process of some type. Copyright protects only the words an author uses to express an idea, not the idea itself.

EXAMPLE: Mary has invented the widget, a device only dreamed about for decades. She obtains a patent for her invention. She manufactures and sells the widget herself. She also writes and publishes a technical manual, The Widget Owner's Survival Guide. The patent law prevents anyone from manufacturing and selling widgets without Mary's permission. The copyright law prevents anyone from copying the manual without Mary's permission.

Obtaining a patent can be a difficult and timeconsuming process (it usually takes years). See Patent It Yourself, by David Pressman (Nolo), for a detailed discussion.

3. Trade Secrets

A trade secret is information or know-how that is not generally known in the community and that provides its owner with a competitive advantage in the marketplace. The information can be an idea, written words, formula, process or procedure, technical design, list, marketing plan or any other secret that gives the owner an economic advantage.

If a trade secret's owner takes reasonable steps to keep the confidential information or know-how secret, the courts of most states will protect the owner from disclosures of the secret by:

• the owner's employees
• other persons with a duty not to make such disclosures
• industrial spies, and
  competitors who wrongfully acquire the information.

That is, the trade secret's owner may be able to sue the infringer and obtain an injunction and/or damages. However, once information becomes widely known—for example, through publication—it loses its trade secret status and courts will not protect it.

EXAMPLE: Recall that Mary, in the second patent law example above, wrote a training manual for her widget invention. This manual was automatically protected by copyright. If the manual is also kept confidential (Mary only allows her employees to read it and makes them sign agreements to keep it confidential), it may also be entitled to trade secret protection. However, once Mary publishes and distributes the manual widely to the public, any trade secret protection would cease.

Since most authors want their work to be published and as widely read as possible, trade secret laws usually have little application to written works. However, trade secret protection may be important to authors of written works containing competitively advantageous information that has been kept confidential. Trade secret protection is provided only under state law, and varies from state to state. For more information on protecting trade secrets, see Nondisclosure Agreements: Protect Your Trade Secrets & More, by Richard Stim and Stephen Fishman (Nolo).

4. Contract Protection for Ideas

Consider this example: Manny, a TV producer, agrees to pay Sally $10,000 for telling him an idea she has for a new TV show. Sally tells Manny the idea, but he fails to pay. Does Sally have any recourse against Manny?

We know that copyright does not protect ideas, so Sally cannot sue Manny for copyright infringement. Her idea is not for a new invention, so she gets no help from the patent laws. And let's assume the idea is not a trade secret.

All is not lost for Sally, because some courts have held that if a person agrees to pay another person for disclosing an idea she has, the agreement constitutes an enforceable contract. This means that if the person fails to pay what he promised, the person who disclosed her idea may be able to sue and collect the promised payment. This might mean that Sally can sue Manny for breach of contract and collect the $10,000. Some courts would permit Sally the $10,000 only if her idea was novel and concrete and Manny actually used it. Others would not require this. See Nondisclosure Agreements: Protect Your Trade Secrets & More, by Richard Stim and Stephen Fishman (Nolo), Chapter 8, for a detailed discussion of idea protection.

However, there are very few Mannys or Sallys in the real world. Rarely, if ever, will a producer, publisher, editor or other person agree to pay an author for a mere idea. Thus, contract protection for ideas is usually more theoretical than real. The best way to protect your ideas is to disclose them only to people whose integrity can be trusted.

Some Common Copyright Misconceptions

Copyright is a fast-changing area of the law. The copyright laws were completely rewritten in 1978 and major changes were made again in 1989 and 1998. Many people who are unaware of the impact of these changes have ideas about copyright that are no longer true. For example:

• "A work must be registered with the U.S. Copyright Office to be protected by copyright."
• This hasn't been true since 1978. Copyright protection begins automatically the moment a work is set to paper or otherwise fixed in a tangible form.
• "Only works that have a copyright notice on them are protected by copyright."
  Use of copyright notices has been optional since March 1, 1989.
• "No one can use or photocopy a protected work without the owner's permission."
  This has never been true. You can photocopy or otherwise use protected works so long as the use comes within the bounds of fair use—that is, does not diminish the value of the protected work.
• "You can copyright your great ideas."
  This also has never been true. Copyright only protects the expression of an idea, not the idea itself.

Designing Cement Plant Handbook - Abbreviations

Abbreviation

Full Form

A/amp a.c. AC/a.c. AF Al2O3 AM Annex. Atmos. b.c. B.D. / b.d. B.F. B.G./b.g. B.I. BE B.F.S.C./b.f.s.c. B.H.N. B.I.S. B.T.U. / b.t.u. BZ C C.E.O. c.i. C.I.F./ c.i.f. C.S.T. C2S C3S C3A C4AF Ca C03 Ca CaO CCS CCTV CH4 Cl2 cm cm2 cm3 / c.c. CMA CO CO2 D.B.C. / d.b.c. d.g.set D.O.L. D/E ratio D.C. / d.c. DDC dia. E.O.T ENQS E.S.I.S. ESP / esp f.a.d. Fl. f.k.pump FO.B./f.o.b. FO.R. / f.o.r. Fe2O3 Fig. FLS GM. GCT / gct gm gms/cc h.d.p.e. H.O. H.P. h.s.d. H.T. / h.t. H2SO4 HHVlhhv HM HP/hp hr ht I&PC I.C.I.C.I. I.D.B.I I.F.C.I I.F.M.R. I.R.R. I.T.L ILC IR ISO Jr. K2O KCAL / kcal Kcal/kg KG/kg kglkg Kg/cm2 kg/m3 km KV KVA KW/kw KWH /kwh kwh/ton L.O.I./ l.o.i. L.S.F. l.s.h.s. L.T. / l.t. l/d ratio LHC LHV/lhv M/m M.C.C. M.D. M.G./mg M.I.S. M.T.P.A./m.t.p.a. m2 m3 max MD mgm mgm/nm3 mgm/m3 MgO min. mm mmwg MVA N2 Na2O NCBM nm3 NO No./no. NO2 NOx 0c / 0C 0f/0F O2 OPC / opc P&I P.C. P.C.B. P.D.S. p.f. P.L.C. P.O. P2O5 Para PPC/ppc RDSO RITES R.M.C. r.m.s. r.p.m. RBI RCC RHC RSP S s.c. S.M. S.R. S.T. SID SC/sc SCA/sca sec. SiO2 SLC SO2 Sp. gr. Sq.cm/gm Sq.cm Sr SR/sr SRC SRR STD T.E.P.R. T.E.P.S. T.P.A./t.p.a. T.P.D./t.p.d. T.P.H./t.p.h. T.P.S. T/m3 TDS Temp. TiO2 Transfr TV V.P.S. V v.r.m.N.R.Mill V.S.Kiln VAT VDV v.i.p. v.v.i.p. w.r.t. WPC wt yr

amperes air conditioner alternating current alumina ratio alumina alumina modulus Annexure atmospheric pro belt conveyor bulk density burnability factor broad gauge burnability index back end ( of kiln) Blast Furnace Slag Cement brinell hardness number Bureau of Indian Standards British thermal unit burning zone (of kiln) carbon Chief Executive Officer cast iron cost insurance and freight central sales tax Di calcium silicate Tri calcium silicate Tricalcium aluminate Tetra calcium aluminoferrite calcium carbonate calcium calcium oxide cold crushing strength closed circuit television methane chlorine centimeter square centimeter cubic centimeter Cement Manufacturers' Association carbon monoxide carbon dioxide deep bucket conveyor diesel generating set direct on line debt / equity ratio direct current direct digital control Diameter electric overhead traveling enquiry specifications Employees' State Insurance Scheme electrostatic precipitator free air delivered at 20°C financial institution fuller kinyon pump free on board free on rail iron oxide figure EL.Smidth general manager gas conditioning tower gramme grammes per cubic centimeter high density polyethylene head office Himchal Pradesh high speed diesel oil high tension sulphuric acid high heat value hydraulic modulus horse power hour height instrumentation and process control Industrial Credit and Investment Corporation Industrial Development Bank of India Industrial Financial Corporation of India Institute of Financial Manageent Resources internal rate of return Industrial Training Institute in line calciner insoluble residue International Standards Organisation Jumor potassium oxide Kilo calorie kilo calorie per kilogram Kilogramme kilogramme/kilogramme load in kilogrammes per sq. centimetre kilogrammes per cubic metre kilometer kilovolts kilovolt amperes kilowatt kilowatt hour kilowatt hours/ton loss on ignition lime saturation factor low sulphur high sp. gravity low tension length to diameter ratio low heat cement low heat value metre motor control center Managing Director metre gauge management information system million tons per annum square metre cubic metre - actual volume maximum maximum demand milligramme milligram per normal cubic metre milligram per cubic metre magnesium oxide minute/minimum milli metre pressure/draft in mms of water above/below atmos pressure mega volt amps = 1000 * kva nitrogen sodium oxide National Council of Cement and Building Materials normal cubic metre nitrous oxide number nitrogen dioxide nitrogen oxides degrees centigrade degrees Fahrenheit oxygen ordinary portland cement process and instrumentation personal computer Pollution Control Board power distribution system power factor programmable logic controller post office phospherous pentoxide paragraph Portland Pozzolana Cement Research Design & Standards organisation Rail India Technical & Economic Services ready mix concrete root mean square revolutions per minute Reserve Bank of India reinforced cement concrete rapid hardening cement reinforced suspension preheater sulphur screw conveyor silica modulus silica ratio sales tax star delta squirrel cage specific collection area Second silica I silicon dioxide separate line calciner sulphur dioxide Specific gravity square centimeter per gramme Square centimeter senior slip ring sulphate resistant cement stator rotor resistance straight trunk dialing techno economic feasibility report techno economic feasibility studies Tons per annum Tons per day Tons per hour thermal power station tons per cubic meter technical data sheet temperature titanium dioxide transformer television uninterrupted power service volts vertical roller mill vertical shaft kiln value added tax visible display unit very important person very very important person with respect to white cement weight year

Electrical Engineer Portable Handbook

1.0 INTRODUCTION

This chapter provides information of a general nature that is frequently needed by the electrical design professional. Information that follows in subsequent chapters is more specific and closely follows the design process.

1.1 CHECKLISTS

The following checklists should prove useful in the execution of projects.

Figure 1.1: Project to do checklist (electrical).

Figure 1.2: Drawing design checklist (electrical).

Figure 1.3: Site design checklist (electrical).

Figure 1.4: Existing condition service & distribution checklist.

Figure 1.5: Design coordination checklist (electrical).

Figure 1.6: Fire alarm system checklist.

1.2 ELECTRICAL SYMBOLS AND MOUNTING HEIGHTS

Electrical Symbols

Electrical symbols can vary widely, but the following closely adhere to industry standards. Industry standard symbols are often modified to meet client and/or project specific requirements.

Figure 1.7: Electrical symbols.

Mounting Heights

Mounting heights of electrical devices are influenced by and must be closely coordinated with the architectural design. However, there are industry standard practices followed by architects as well as code and legal requirements, such as Americans with Disabilities Act (ADA) guidelines. The following recommended mounting heights for electrical devices provide a good guideline in the absence of any specific information and are ADA compliant.