wiring for electrical house heating

... of Foreign Language Ha Noi University of Technology Results The course requirements in textbook of English for Electrical Engineering: Before the lesson - Students are required to prepare for ... Bich Ngoc D06K52 Faculty of Foreign Language Ha Noi University of Technology The Situation of Learning English for Electrical Engineering of D06k52 Students in Faculty of Foreign Language, Ha Noi ... English It is really useful for learn ESP subjects effectively and help learns to save more their time And according to the course requirements in textbook of English for Electrical Engineering,...

Ngày tải lên: 13/12/2013, 12:15

... looking for, search for some specific information in a certain time allowance For example, if you want to search dates, you should use the key word “When” If you want to know the time, please look for ... a title for a paragraph or a text etc for students to *Scanning: Scanning is another useful skill to locate a specific item of information that we need Readers pass over irrelevant information ... the study for informal discussion The data collection method To reach the primary purpose of the study, a survey questionnaire has been chosen as the main instrument for data collection for this...

Ngày tải lên: 29/01/2014, 10:33

... case 3.1.8 Instrument Transformers The material that follows is a brief summary of information on instrument transformers as measurement elements For more extensive information, consult American ... connected to rotate forward for an inductive load, they will rotate backward for capacitive loads For 3-phase 3-wire circuits and 3-phase 4-wire circuits, phase-shifting transformers are used normally ... National Standard C57.13, Requirement for Instrument Transformers; American National Standards Institute; American National Standard C12, Code for Electricity Metering; Electrical Meterman’s Handbook,...

Ngày tải lên: 21/03/2014, 12:12

... unity for vacuum to slightly greater than unity for gases at atmospheric pressure, to for common insulating solids and liquids, 35 for ethyl alcohol and 91 for pure water, and 1000 to 10,000 for ... Fire-refined copper is a lower-purity grade intended for alloying or for fabrication into products for mechanical purposes; it is not intended for electrical purposes Casting copper is the grade of ... industry, but for this purpose it is obtained in the form of ferrosilicon, which is a coarse granulated or broken product It is very useful as an alloying element in steel for electrical sheets...

Ngày tải lên: 21/03/2014, 12:12

... of the nth term Application of Performance Equations The equations of performance for the various portions of the NSSS may be used for mathematical analyses or for development of simulations Simulation ... produced for further fission action For a 1300-MW (electrical) light-water nuclear plant, a representative core assembly might involve 241 fuel assemblies each weighing approximately 660 kg, for a ... and therefore make more efficient use of coal Postcombustion control processes are widely used for the capture of sulfur and particulate Limebased scrubbers for SO2 removal and equipment for particulate...

Ngày tải lên: 21/03/2014, 12:12

... accounting for all losses required to generate the propeller-shaft output work, this fuel rate includes the requirements for the ship’s “hotel” electric load, freshwater evaporators, and steam for heating ... often cause a thrust reversal Therefore, it is usually necessary to provide an “active” thrust bearing for normal loading and an “inactive” thrust bearing for reverse loading The control-valve ... and operating forces are high Speed/Load Control Systems After a choice has been made from the types of valves available for steam admission to the turbine, a means must be provided for positioning...

Ngày tải lên: 21/03/2014, 12:12

... The constant K is 234.5°C for copper, 242°C for silver-alloyed copper used for hollow conductors, and 225°C for electrical conductivity aluminum Discharge coolant method For directly cooled armature ... Rotating Electrical Machines—Methods for determining losses and efficiency from tests (excluding machines for traction vehicles) IEC 60034-3, Rotating Electrical Machines—Specific requirements for ... number of slots per pole per phase g ϭ electrical angle between slots qs ϭ electrical angle of skew Here, the relevant angles are stated in electrical terms The electrical angle is p times the physical...

Ngày tải lên: 21/03/2014, 12:12

... coil equal to V for a change of 108 linkages/s (Mx/s) for each turn of the coil, or E ϭ (⌬fT ϫ 10 –8)/t V If the flux lines are deformed by the motion of the coil conductor before they are broken, ... armature-core length, in K1 ϭ 18.5 for noncommutating-pole machines ϭ for machines with commutating-pole length ϭ Lr K2 ϭ 1.0 for machines using nonmagnetic bands ϭ 1.7 for machines using magnetic bands ... specified ambient-air temperatures for various machine enclosures and duty cycles Typical values are 40°C for Class A systems, 60°C for Class B, and 80°C rise for Class F systems on armature coils...

Ngày tải lên: 21/03/2014, 12:12

... spillway, etc Bulkhead gate A gate used either for temporary closure of a channel or conduit before dewatering it for inspection or maintenance or for closure against flowing water Bulkhead gates ... main step-up transformer Smaller plants may only have provision for switching via a switchyard breaker on the high voltage side of the step-up transformer, the generator and transformer being connected ... Transformers associated with hydroelectric generation may differ somewhat from those used in transmission and distribution applications For example, it is not uncommon for a single step-up transformer...

Ngày tải lên: 21/03/2014, 12:12

... of K for Eq (10-58) High-voltage winding BIL, kV Self-cooled and water-cooled ratings Forced-air and forcedoil-forced-air-cooled 25% to 35% above self-cooled rating Forced-air and forced-oilforced-air-cooled ... the transformer bank FIGURE 10-31 Exciting transformer with taps in the secondary and a series transformer forming complete isolation for tap-changing equipment Tap-Changer Designs for Moderate ... correction of 0.4% of rated kVA for self-cooled transformers or 0.5% of rated kVA for forced-air-cooled or forced-oil-cooled transformers for each 330 ft of additional altitude above 3300 ft...

Ngày tải lên: 21/03/2014, 12:12

... important solar application is for residential water heating Today, systems for hot water production in single-family houses are dominant; although, in the future, solar heating systems will be used ... examined Market forecasts are provided for capacity, new projects, and annual revenue for the 2002 to 2008 time frame The forecasts cover national, regional, and world markets for both single-site ... recommended for their high efficiency of lumens per watt Batteries are required for PV lighting systems Deep cycle batteries specifically designed for PV applications should be used for energy storage for...

Ngày tải lên: 21/03/2014, 12:12

... use of each type of fuel Coal, for example, would include track networks for train transportation, river networks for barge transportation, and highway networks for truck transportation There ... solely for secondary heat conversion or for additional fuel combustion Such distributed generation, often called renewable sources, decreases the need for the electric transmission system for basic ... high value of natural gas for chemical and space -heating uses, its future use as an energy source for electric generation is limited Natural gas is a significant fuel for distributed generation,...

Ngày tải lên: 21/03/2014, 12:12

... owner faces Table 13-7 contains the data for the illustrations of financing effects in the remaining tables The payments for principal and interest are shown for a debt of $1000 to be repaid over ... installation, and the lessee party pays for its use Since the lessee must pay enough profit to the lessor for the lessor to be willing to install the property for the lessee’s use, this arrangement ... of equipment that may not work well for its application By leasing, the lessee gets a chance to work with the equipment and see if it performs as expected—before spending large amounts of investment...

Ngày tải lên: 21/03/2014, 12:12

... Touch perception for 50% of women Grip perception for 1% of women Touch perception for 50% of men Grip perception for 1% of men Grip perception for 50% of women Grip perception for 50% of men Startle ... 22.9(n Ϫ 1) B 14-13 for n Ն for n Ͻ for n Ն where B is the bundle diameter, cm The L50 level for each phase is obtained from AN50 ϭ AN5 Ϫ ⌬A where gc ⌬A ϭ 14.2 g Ϫ 8.2 (14-28) for n Ͻ gc d ϭ 14.2 ... 2ഛdഛ6 For each phase, the L5 noise level is given by AN5 ϭ Ϫ665 g ϩ 20 log n ϩ 44 log d Ϫ 10 log D Ϫ 0.02 D ϩ AN0 ϩ K1 ϩ K2 (14-27) with AN0 ϭ ϭ K1 ϭ ϭ 75.2 67.9 7.5 2.6 for n Ͻ for n Ն for n ϭ for...

Ngày tải lên: 21/03/2014, 12:12

... in a common tank for each 12-pulse converter bridge For larger converters, three, single-phase transformers with double secondary windings may be used for each 12-pulse bridge For the largest ... developed for communications outages In a bipolar system, a master control is used for coordinated schedule changes and calculation of the current orders for each pole The master control is used for ... system through ac phase reactors and power transformers Harmonic filters are located between the phase reactors and power transformers Therefore, the transformers are exposed to no dc voltage stresses...

Ngày tải lên: 21/03/2014, 12:12

... power system they serve For example, a unique load forecast model is developed for each case Load Forecast This program forecasts hourly loads to days in advance Load-forecasting methods are ... check for bad data and to establish a consistent network solution as a basis for security analysis and power flow studies The bus-load forecast provides a forecast for each individual bus, for ... in maintaining frequency, which is uniform among areas, but are individually responsible for maintaining each area’s scheduled net interchange The formula for this is ACE ϭ B( factual Ϫ fscheduled)...

Ngày tải lên: 21/03/2014, 12:12

... Fig 17-17 for a Y-delta transformer and (2) in Fig 17-18 for a three-winding Y-delta-Y transformer Two rules, frequently used in laying out the wiring for differential protection of transformers ... 1.51 1.57 100% Forced-air-cooled (OA/FA/FA) over 133% of self-cooled rating or forcedoil-cooled (FOA or OA/FOA/FOA) with % load before peak of Note: For forced-air-cooled transformers, the peak ... FIGURE 17-18 Transformer differential protection for a Y-⌬ Y transformer The current transformers in the leads to the Y-connected winding should be connected in delta; current transformers in the...

Ngày tải lên: 21/03/2014, 12:12

... used for r in Eq (18-2) r ϭ 0.528 !A for strands, r ϭ 0.5585 !A for 19 strands, r ϭ 0.5675 !A for 37 strands, where r ϭ equivalent radius, in, and A ϭ area of metal, in2 Frequency is 60 Hz for ... transformer and intended for bolting to adapter plates for direct pole mounting or on crossarms by means of steel hangers attached securely to the transformer Banks of three single-phase transformers ... 18-33, 2-phase transformer connection for 3- to 2-phase transformation wires and neutral being used on the primary side of the transformers Current in each of two singlephase transformers connected...

Ngày tải lên: 21/03/2014, 12:12

... developed for limited or particular uses, rather than for complete wiring systems for a building The NEC should be consulted for specific requirements in each case Service-entrance (SE) cable is a form ... not exceed 15 A for 14 AWG, 20 A for 12 AWG, and 30 A for 10 AWG copper; or 15 A for 12 AWG and 25 A for 10 AWG aluminum and copper-clad aluminum after any correction factors for ambient temperature ... not exceed 15 A for 14 AWG, 20 A for 12 AWG, and 30 A for 10 AWG copper; or 15 A for 12 AWG and 25 A for 10 AWG aluminum and copper-clad aluminum after any correction factors for ambient temperature...

Ngày tải lên: 21/03/2014, 12:12

... are 1.4 for motors rated 1/20 to 1/8 hp; 1.35 for 1/6 to 1/3 hp; 1.25 for 1/2 hp to the frame size for hp at 3600 r/min For all larger motors through 200 hp, the service factor is 1.15 For 250 ... switching is done with a contactor for the slip-ring type, and with thyristors on the rotating rectifier assembly for the brushless type Except for the disconnection for starting, the synchronous-motor ... 20-19 Cycloconverter Drive A unique application for large low-speed synchronous motors is for gearless ball-mill drives for the cement industry For a recently installed drive, the motor is rated...

Ngày tải lên: 21/03/2014, 12:12