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FACULTY OF ENGINEERING AND ARCHITECTURE DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING

EECE 475 INDUSTRIAL ELECTRIFICATION

Prof. H. Chahine 1

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(EECE 475) INDUSTRIAL ELECTRIFICATION EVERY FALL TERM (ELECTIVE) Catalog Description: 3 credits Medium and low voltage installations, Lighting, Practical applications of electric machines, Motor control centers, Emergency power supplies, Auxiliary systems Prerequisites: EECE 210 Electric Circuits, EECE 370 Electric Machines and Power Fundamentals References:  Mechanical and Electrical equipment for Buildings (11th Ed.) Stein and Reynolds, J. Wiley and Sons, 2010  Electrical Installations Handbook (3rd Ed.) Seip, Siemens – J Wiley and Sons, 2000.  Others Course Objectives: This course enhances the theory and applications of the main equipment used in the medium and low voltage installations and their designs and their regular, standby, and emergency power supplies. Electric motors applications, starters, and control. It handles light sources, their applications, and lighting design. Objectives:  To introduce students to electrical installations, lighting, and electric drives.  To familiarize students with various basic equipment used in medium and low voltage installations, electric drives, and lighting.  To teach students the installations power supply problems and solutions.  To introduce students to the design main considerations and procedures as practicing engineers and the implementation of the correlated theories studied according to National Electric Code, European and British Standards.  To cultivate the spirit of teamwork, market research, and the analysis and synthesis to produce optimal design for the installations (students have to work in teams chosen by the instructor of the course to foster interaction skills and communication). 0 2

Draft Topics Covered:  Cables conductors materials, main insulation types, jacketing, and loading.  Busways, conduits, ducts, and raceways.  Switchgear: switches, circuit breakers, and fuses.  Panel boards, switchboards, sockets, etc…  Installations distribution systems, power factor correction, and grounding  Power supply interruptions causes and results. Standby, vital and emergency power supply sources, and implementation.  Electric wiring design: main consideration, load estimation, design procedure.  Building automation  Electric service to projects in overhead or underground-Medium to low voltage networks. Distribution sub-stations  Electric motors: Classification, choice to match mechanical loads requirements, starters, and protection. Programmable logic controllers.  Lighting: light sources characteristics and applications. Lighting goals and design procedures.  Design projects using calculations analysis and correlated software designs Learning Outcomes: Outcome 1: Students are knowledgeable in the construction, principle of operation, and applications of the equipment used in electrical installations systems. Outcome 2: Students are knowledgeable in the field of industrial and buildings complexes electrification. Outcome 3: Students will demonstrate an ability to choose the proper electric equipment for medium and low voltage installations and their relevant power supplies (regular, standby, emergency). Outcome4: Students will demonstrate an ability to design installations, electric drives, and lighting projects according to relevant international codes and standards. Outcome 5: Students will demonstrate and ability of relevant ways of electric service to supply the installations, and the coordination with the local electric utility during the early stages of design to reach optimal solutions. Outcome 6: Students will demonstrate an ability to interact, communicate, and function in professional multidisciplinary teams. . Assessment: Exams: Quiz I (20%), Quiz II (20%), Coursework- Project (20%), Final (40%) Students are introduced to My six commandments for Professionalism; Team Work Time Management Communications Analysis and synthesis for problems Adaptability: Ability to survive requires ability to adapt within values Prober self estimation

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1.Introduction: Industrial electrification deals with electrical equipment and installations for the utilization of electric power by the consumer. i.e. domestic, industrial, agricultural etc. This course handles the equipment, materials, protective devices etc. their characteristics, their installation methods and optimization, and the problems encountered in the utilization and exploitation of electric power and the solution for them. Equipment is manufactured and installations are carried out according to standards and specifications to ensure the: 1. Reliability of supply i.e. continuity, stable voltage level etc. 2. Safety of personnel. 3. Safety of installations. At optimum cost which satisfies the specifications (material, equipment and installation). Codes, standards, and regulations were developed by various countries and international bodies during the period of 1880today and these are revised regularly. The design projects in this course apply the course materials together with the introduction of students to : a) team work b) time management c) procurement of equipment d) energy efficiency designs …. At optimal cost

Main Bodies that issued above-mentioned codes etc.: 

I.E.C: International Electro-technical Commission

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U.S.A: NEC (National Electric Code)

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NEMA (National Electrical manufacturers association)

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IEEE (Institute of Electrical and Electronics Engineers)

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ANSI (American national standard institute)

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European Standards: CEN are practically applied in Europe.

Previously the following specifications were applied in the following countries: 

U.K: British Standards. BS ( I.E.E. Regulations)

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Germany: VDE ( Verband Deutcher Elktrotechniker )

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DIN (Deutche Industrie Normen)

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France: UTE (Union des Techniciens Electriciens)

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NF ( Normes Francaises) …….etc

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Lebanon: Humble attempts in the early sixties. New specs started to be issued recently. 4

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Chapter 2: Electric materials and Protective Devices 2.1 Cables and Wires 2.1.1 Conducting materials: Metals used for cables and wires are mainly copper (Cu) and Aluminum (Al). To evaluate conducting material, the following elements should be considered: 1. Price 2. Conductivity/ Resistivity 3. Mechanical Strength 4. Weight 5. Installation costs( note that as weight increases, labor cost for installation increases) Remark: Gold is the most conductive material, however; its cost is astronomical 2.1.1.1 Copper: Copper is the relatively very feasible conducting metal available for electric cables and wires. It could be hard drawn or annealed. 

Hard drawn for overhead lines because of higher tensile- mechanical strength

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Annealed wires are relatively pliable and soft hence they are suitable for cables and wires. It is tinned before used for some insulation material.

1. Price: It is expensive, over 5155 USD/TON, August 17, 2015 compared to 7300 USD/ ton on August 27,2013 on London Metal Exchange (LME) which is the base on which the major world dealers would carry their transactions. 2. Resistivity: Its resistivity is 17.24 Ω mm. 5

Draft 3. Strength: Tensile strength= 40 K force/m.m2. Thus it is strong enough under normal conditions to withstand the pressure safely .I.E So the strength is the real ability the cable can carry a maximum of 40 Kg/ mm. The mechanical strength is how much pressure the cable or wire can withstand. 4. Weight: Copper is heavier than steel. Specific gravity (weight of 1 KG/dm3 or 1TON/ m3) Sg= 8.9 5. Installation: 

For larger cross section (if it is feasible) use aluminum instead of copper as it is much heavier and thus requires much higher labor cost

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As the cross section increases, the price of installation increases

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Search for proper workmanship for installation

Remark: Below 10 mm2 , aluminum is very rarely used. 2.1.1.2 Aluminum: It is used for its inherently weight advantage over copper : in weight and may be in price for equivalent Cross-sections. 1. Price: Sensibly cheaper than copper. Its cost is 1540 USD /ton on August 17, 2015 versus 1837 USD/ TON, August 27, 2013. 2. Resistivity: It is a good conductor of electricity i.e. resistivity is 28.5 Ω m.m. It is 60 % more resistive than copper. Hence, the cross sectional area used must be 60 % larger. (16 mm2 Cu → 25 mm2 AL to have the same resistance and thus there is a need to use more insulation material) 3. Strength: Tensile strength= 20-30Kforce/m.m2. For overhead lines, they break down and thus, we need aluminum alloy or steel reinforcement. 4. Weight: Specific gravity= 2.7 5. Installation: 

It is much lighter than copper (about 1/3) and pliable (flexible) but very demanding in its terminations (the sealing ends) and joints workmanship. it has a very serious difficulty due to its cold-flow characteristics i.e. when it is under pressure and is subjected to air its joints loosen and ALO (Aluminum Oxide) is formed. This oxide, which appears within minutes on any exposed Al surface, is an adhesive, poorly conductive film that must be removed and prevented from reforming, if a successful joint/ termination is to be carried out. If not, the ALO produces a high resistance joint with excessive heat generation and possible incendiary effect (fire).

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When a high resistance is in series with a normal resistance in the same circuit, current would pass and the cable would heat up.

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What to do? Special tools and techniques were developed and skilled workmanship is needed to overcome these difficulties. Hence aluminum started to be used safely when it is 6

Draft economically feasible for 25 mm2 and above, but not for branch circuits. Upon exposure, ALO forms and there would be a need to form a proper joint. There is a need to clean the cable and with special compression tools and additives to form a proper joint. 

Certain American states forbid the usage in the residential branch circuits as it may cause fire.

2.1.1.3 Feasibility of Conductor: Copper is a strategic material and its price fluctuates at London Metal Exchange. (L.M.E) or Chicago Stock Exchange etc. Sometimes it is cheaper to use copper and at others aluminum etc. Cables are tendered with price revision formula to account for metal cost variations For small cross-section of cables up to 16 mm2 copper is preferred for three main reasons: 1) Feasibility and availability of skilled labor & kits. 2) The larger cross-section of aluminum equivalent to copper may lead to much larger cost of insulation i.e. larger diameter of insulation. 3) Larger conduits sizes. 2.1.1.4 Standard Cross-sections of Conductors: We have the Metric, MCM, and AWG standards. A circular mil is an artificial area and equal to the square of diameter given in mils. M represent its multiplication by 1000.MCM& AWG are nominal sections used in the USA. (See Chart Attached) Metric: Basically cross section=

d2 × π=r 2 × π 4

d: conductor diameter in mm

Standard Cross section (mm2): 1.0

1.5

2.5

4.0

6.0

10.0

16.0

25.0

50.0

70

95

120

150

185

240

300

400

500

630 …. 1000

American: Not exact (due to the absence of π ¿ 

MCM: thousand of circular mils o ½ inch Diameter= 500 mils 2 d 2 ∈mils o MCM= 500 = 1000 1000

o MCM= [d” x 1000)2 / 1000 (“ means inch)

i.e. 250MCM

o 1 circular mil= 0.507 of MM2 7

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AWG o Nominal sections used in American Standards

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2.1.2 Ampacity, derating, and Correction factor: 2.1.2.1.1 Ampacity: Is the cable maximum current carrying capacity; it is determined by the maximum sustained operating temperature that its insulation can withstand continuously without any change in its characteristics . The limit on the Ampacity is determined by maximum operating temperature the cable the can withstand. The temperature depends on 1) Heat produced by I2R losses in the cable,2) installation type( buried in earth, concealed, openair…3) The Ambient temperature: the lager the difference between the temperature of the surrounding and that of the cable, the higher the rate of heat flow. The operating temperature depends on: 1) Current flowing in the cable (I2R losses) 2) The resistance of cable 3) The environment i.e. open-air, enclosed….,and the ambient temperature etc. Ampacity of higher voltage cables with the same conductor(s) and insulation types is lower. (More insulation thickness is used which hinders heat dissipation flow and thus higher temperature) 2.1.2.1.2 Derating Factor (grouping): When more than 3 conductors are placed closely to each other undercover and thus being unable to be dissipated heat easily, their temperature rise is greater. i.e. their rate of temperature rise is far higher in enclosed raceways than in the free-air. As the number of conductors increases, Ampacity is multiplied by a factor less than 1. We can’t load them to the same current (lower facility of heat dissipation); hence as the number of conductors increases, the derating factor would be smaller and hence their Ampacity would decrease (with the same cross section and voltage); as the number of cables increases the value of the derating factor decreases reaching 35% for 41 conductors or more in a covered raceway, according to NEC.

2.1.2.2 Correction factor: The maximum Ampacity of a cable is rated for certain ambient temperature i.e for normal cables it is 300 C (In higher temperature areas the ampacity decreases and thus there is a need to use a correction factor less than one).The correction factor depends on the design ambient temperature of the environment in which the cables are placed in. Correction Factor depends on the designed ambient temperature such that:  If the ambient temperature is 1  If the ambient temperature is larger than 300 C the correction factor is 0.85 lagging system. (thrysistor switched capacitors are used for PF correction)

3.4.3. Frequency Variation: Frequency variation due to large load shedding (cut off). The speed of the generator increases, motor frequency increases and thus it is overloaded. Governor controls the amount of fluid to turbine. If f increases, governor of the turbine will reduce the flow of fluid, thus reducing speed of the generating-set and hence frequency adjusted. f decreases then the system is overloaded motor overheats as the speed falls, output do

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Emergency, Vital, and Standby Supplies How to avoid power cuts: By having a continuous supply. Loads to be supplied, when the main system is cut, are classified as follows: 1. Vital Loads: are loads that should have uninterrupted supplied to avoid the high cost of power interruption and or damages to supplied plants which may be disastrous (chemical plant, food treatment, metal furnaces…). 2. Emergency Supply is used for protection of lives: Certain loads by law should have an uninterrupted power supply. Example: exit signs, fire pumps, fans, water sprinklers etc. … → required by law, they are mandatory. 3. Critical loads i. Chemical and metal industries 41

Draft ii. Loss of data upon electricity cut off when working on a computer iii Hospitals: operations room ,CCU, CSU, incubators , intensive care etc…

Vital Loads Supply System :(see diagram)

To connect the two LV bus bars as wished; the switch between them can be opened or closed.

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Auxiliary power needed to run the generator

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Four possibilities of instant power supply

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Customer: Supplied by a ring MV supply.

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Two generators are run at MV because they are connected to the same bus bar of the MV voltage of the transformer.

It is inadmissible to load a diesel engine at a load of ¿

40% of its rated power continuously

Standby: Supply all loads used or a portion? Factors to consider are: Economical, safety, prestige…… Priority is given to:

1. Safety and prestige….. 2. Material losses and plant damage.

3.6 Supply Sources: 42

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Equipment used to feed the power necessary in case of a power interruption. Two major sources of relative size:  Generator sets. 

Battery equipment (battery + inverter to supply from a DC source)

3.6.1 Generating- sets Generator is driven by a prime mover (diesel engine, gasoline motor, gas, steam, water, wind turbine etc….)

Advantages are: 1. Unlimited KVA capacity ,provided that fuel and fuel tanks are available. 2. Peak shaving: utility for MV usually put a very high rate during peak hours in order to deter the usage of its supply). If we have another power source, we avoid paying more during the four hours of peak a day by using a generating -set. EXAMPLE: EDL KWH Rates: 21 cents= 320 L.L/ KWH (Peak hours) 115 L.L/ KWh, 6 AM to sunset normally (normal hours) 80 L.L/ KWh (4 hours after sunset - 6 AM) off peak 3. Very long life. (150,000 hour substantially) Disadvantages are: 1. Noises (gen sets are enclosed in metal casing, in buildings – Apply silencers especially in buildings at extra cost and lower efficiency , because it has to be more cooled  more fans more power for auxiliary sources, then less power output. 2. Vibration (damping layers are installed in the base i.e. usually rubber pads) 3. Nuisance of exhaust gases piping (producing fumes that are not user friendly, sooth that may be cancer provokers). 4. Fuel storage and disposal when not suitable to be used.( polluting the atmosphere) 5. Need for regular maintenance and testing. Silencing: Cost more, use fans to cool it to dissipate heat, efficiency would be lower (losing power through other auxiliary surfaces, gen set= shorter life span) 3.6.2 Battery: 43

Draft 1. Used for limited rating of emergency power because they need a very large space. Battery when operated produces fumes (part of which is acidic) and thus has to be removed. 2. Instant in its supply, basically for lighting, in the UPS computers, medical critical loads (CSU) and certain fractional KW equipment rating (less than 1kw) Comparison of Engine and Battery: 1. Area needed 2. duration of service 3. AC or DC 4. Space for large capacities 5. Ventilation is large for generating -set because it has to be cooled ; batteries need to be ventilated because of chemical reactions that dissipate heat) 6. Life span for battery is not normally long. 7. Large space- large size of battery 8. No vibration in battery; generating –sets need dampers

Load diagram: chop the peak load. => To avoid added extra supply cost at peak hours (p-772) Electrical Power Production Cost:  Pc= (βC + F + OM) + Utility Rates. Annual cost of electricity consumed. 

OM: Operation and maintenance about 1 % of the cost of the project.

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C: capital cost of plant (to prepare the infrastructure and to buy and install a KW), cost of KW installed for the utility: generation, transmission, and distribution).

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Β: capital charge factor, it has two items; (I and N). 44

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I: discount (interest) rate on the capital.

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N: life span of the plant.

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