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exceptional conditions. Compatibility levels for individual harmonic voltages in the low-volt- age network are shown in Table 6.7. They are given in percentage of the fundamental voltage. 6.8.4 IEC 61000-3-2 and IEC 61000-3-4 Both IEC 61000-3-2 and 61000-3-4 define limits for harmonic current emission from equipment dr... |
material of side 1 cm has a resistance of 0.001 Ω between its opposite faces. If the same material has a length of 9 cm and a uniform cross-sectional area 1 cm2, what will be the resistance of this length ? [0.009 Ω] 5. An aluminium wire 10 metres long and 2 mm in diameter is connected in parallel with a copper wire 6 ... |
14.2: A cable circuit with an impedance angle of 10° is to be protected by directional over current relays. Specify the connection you use for the directional element and justify by actually working out the connections and the maximum torque angle setting needed for the relay. Specify also the phase shifting network to... |
the phase voltage of the supply. However, current in each phase (or line) will be different due to unequal impedances. (ii) The amount of current flowing in the neutral wire will depend upon the magnitudes of line currents and their phasor relations. In most circuits encountered in practice, the neutral current is equa... |
comply with these Regulations and submit the compliance report every 6 months in standard formats, including transparent data disclosure regarding electrical system, to the Commission. Commission may direct designated agencies to be notified separately, to carry out PQ audit on the basis of compliance reports filed by ... |
the demodulator, a dc offset and higher-fre- quency terms (sidebands) are produced. The second section removes these unwanted terms using filters, thus leaving only the modulating (flicker) signal remaining. The second section also consists of filters that weight the modulating signal according to the particular meter ... |
in a bimetal element is caused principally by load current (I2R) heating. The thermal element also factors in the heat- ing or cooling effects caused by nearby heating or cooling sources (furnaces or air conditioners), as well as changes in the ambient temperature. The size of the bimetal thermal element and its config... |
for the core of an electromagnet ? (i) soft iron (ii) air (iii) steel (iv) tungsten steel 15. The source of a magnetic field is (i) an isolated magnetic pole (ii) static electric charge (iii) magnetic substances (iv) current loop 16. A magnetic needle is kept in a uniform magnetic field. It experiences (i) a force and ... |
log volts Both these potentials are w.r.t. the same neutral plane. Since the unlike charges attract each other, the potential difference between the conductors is VAB = 2VA = 2 2 0 Q d r e π ε log volts ∴ Capacitance, CAB = Q/VAB = Q Q d r e 2 2 0 π ε log F/m ∴ CAB = π ε F / m 0 loge d r ...(i) Capacitance to neutral. ... |
that the field due to it assists that due to the shunt winding. (ii) Differential compound, in which the series winding is so connected that the field due to it opposes that due to the shunt winding. Figure 22.24(a)showsalong-shuntcompoundmotor and Fig. 22.24(b) a short-shunt compound motor. Figure 22.24 Characteristics ... |
if the cables are NATIONAL ELECTRICAL CODE 372 SP 30 : 2011 securely fastened to ensure that physical separation is maintained. 7.4.4.8 A flexible cable may contain more than one intrinsically safe circuit if the cable installation is such as to minimize the risk of damage which could cause interconnection between diff... |
to corrosive vapours. 3) the atmosphere is likely to contain flammable gases or vapours, 4) the wet processes are carried out, or 5) in concealed spaces. Ordinary steel conduits shall not be permitted in areas where flammable vapour may be present, unless it is of type conforming with wiring system (t) and shall not be... |
cable as shown in Fig. 11.18 (i). These electrostatic fields give rise to core-core capacitances Cc and conduc- tor-earth capacitances Ce as shown in Fig. 11.18 (ii). The three Cc are delta connected whereas the three Ce are star connected, the sheath forming the star point [See Fig. 11.18 (iii)]. They lay of a belted ... |
— The earthable point may be the neutral point depending on the type of power system. 3.20 Insulation Monitoring and Warning Device — A device which causes a signal to be given in the event of reduced insulation resistance to earth. 3.21 Movable Distribution Cable — An insulated cable that may be moved from time to tim... |
Since K ≠ 0 only positive sign is taken into account. Therefore C = πε0 2 2 1 h r h r + − F/metre (3.17) The expression for capacitance obtained above is very accurate. However, it could be assumed that the charge is uniformaly distributed which is not very far from the actual condition for power system problems whe... |
is given by the product of the voltage and current at that instant, i.e. the instantaneous power, p D vi, as shown by the broken lines. (a) For a purely resistive a.c. circuit, the average power dissipated, P, is given by: P = VI = I 2R = V 2=R watts (V and I being rms values) See Fig. 15.22(a) (b) For a purely inducti... |
equipment in less hazardous or non-hazardous areas and thus reduce the amount of special equipment required. Hazardous areas can be limited in extent by construction measures, that is, walls or dams. Ventilation or application of protective gas also reduces the probability of the presence of explosive gas atmosphere so... |
due to false signals can result in unnecessary property dam- age and high costs for labor to clean up and repair the site and to replace the furnish- ings. Advances in solid-state electronics and communications have had a profound effect on fire alarm system technology. For example, there are now “smart” automatic fire... |
under section 152 of the Act shall be done only by the Government of National Capital Territory of Delhi or by an officer duly authorized by the Government of National Capital Territory of Delhi (compounding officer) for this purpose. 66. Restoration of supply disconnected on account of theft of electricity:- (1) The L... |
concerned with power quality of the primary and secondary distribution system, the discussion of DG will be confined to generator sizes less than 10 MW. Generators larger than this are typically interconnected at trans- mission voltages where the system is designed to accommodate many generators. The normal distributio... |
turns then, emf induced in coil = 2NBlv sin T If the angle between the plane of the coil and direction of magnetic field is D, then component of velocity perpendicular to the field vU = v cos D (see Fig. 1.66). ? The emf induced in the coil, e = 2 N Blv cos D The direction of induced emf in conductor A and B can be det... |
o i 2 2 1 2 1 2 0 01333 0 06 . . = 0.222 (Ans) Conclusion: During starting major part of the power is developed by the outer-cage but during running condition major power is developed by the inner-cage. Example 9.39 The standstill impedances per phase of the inner and outer cage of a double cage induction motor is give... |
at each joint, find the total reluctance of the circuit. Solution. The conditions of the problem are represented in Fig. 8.11. The area of X-section of the core, a = 20 × 20 = 400 mm2 = 4 × 10–4 m2. Section A Length of magnetic path, lA = 80 + 10 + 10 = 100 mm = 0·1 m \ Reluctance of section A = 4 7 0 0 1 µ µ (4 10 ) 4... |
+ load on −ve side + losses = 150 + 100 + 2 × 3 = 256 kW 350 Principles of Power System (ii) Current supplied by the main generator, IG = 256 × 103/500 = 512 A Load current on +ve side, I1 = 150 × 103/250 = 600 A Load current on −ve side, I2 = 100 × 103/250 = 400 A Current in neutral wire = I1 − I2 = 600 − 400 = 200 A ... |
need not consider the phase shift of 90°. If both magnitude and phase relations are required then we must consider the 90° phase shift. To solve the short circuit problems in which the connection of the ∆-Y transformer is not given, any one of the two connections can be assumed. The only difference in the final results... |
2 1 1 5 Ê ËÁ ˆ ¯˜ . or Ia2 = N N Ia 2 1 1 5 1 Ê ËÁ ˆ ¯˜ ¥ . Now, N2 = 0·8 N1 Ia2 = (0·8)1·5 × 50 = 35·777 A Circuit resistance in first case, R1 = V Ia1 500 50 10 = = W Circuit resistance in second case, R2 = V Ia2 500 35 777 13 975 = = . . W Additional resistance required to reduce the speed; R = R2 – R1 = 13·975 – 10... |
: fr = 1 2 f f —Expressions for Bandwidth—Important Relations in R-L-C Series Circuit—Applications of Series Resonant Circuits—Decibels—Objective Questions. 13. Phasor Algebra 634—665 Notation of Phasors on Rectangular Co-ordinate Axes—Significance of Operator j—Mathematical Representation of Phasors—Conversion from On... |
V. At full load of unity power factor, calculate the power output, power transformed and power conducted. If the efficiency of the two-winding transformer at 0.8 power factor is 95 per cent, find the efficiency of the autotransformer. (Ans. 275 kW; 25 kW; 250 kW; 99.52%) 11. A 200 kVA, 2300/460 V, 50 Hz, two-winding tr... |
Dead Mains to Live Mains When dead mains are connected to live mains, all connections to the live parts shall be made last, and in all cases the phase sequence should be checked to ensure that only like phases are connected together. Before inserting fuses or links in a feeder or distribution pillar controlling the cab... |
33 kV, 3 secs, 3-phase oil C.B. Determine the rated symmetrical breaking current, rated making current, short time rating and rated service voltage. 15.10. Differentiate between type tests and routine tests. What different tests are carried out to prove the ability of a C.B.? 15.11. Describe with the help of a neat dia... |
it possible to switch high levels of power faster than could be done earlier, compensating, in part, for the lack of needed transmission line extensions. Thyristors, like transistors, can turn the flow of electrons ON and OFF, but they can handle larger power loads more effectively than transistors because of their hig... |
× = 79 kW *Lagging kVAR taken by the synchronous motor = 79 tan (cos−1 0·8) = 79 × 0·75 = 59·25 kVAR Input to induction motors = 200 735 5 0 82 1000 × ⋅ ⋅ × = 179.4 kW Lagging kVAR taken by induction motors = 179·4 tan (cos−1 0·707) = 179·4 × 1 = 179·4 kVAR Since lighting load works at unity p.f., its lagging kVAR is z... |
Bird guarding Cage gurading:- It provide on L.T lines when the conductors are in vertical configuration. Cradle gurading:- it is provided when the conductors are in horizontal formation. Bird guarding:- To prevent the fault condition caused due to the bird come in contact with the high tension line bird are fixed ovér ... |
density. Therefore, the conduc- tor diameter of such cables is determined from the consideration of safe current density. For high voltage cables, designs based on this theory give a very high value of d, much too large from the point of view of current carrying capacity and it is, therefore, advantageous to increase t... |
har- monic riding on top of the fundamental frequency. This current wave- form typically indicates that the system is in resonance and a capacitor bank is involved. In such a resonance condition, the rms current is typ- ically higher than the capacitor rms current rating. IEEE Standard for Shunt Power Capacitors (IEEE ... |
is not permitted on distribution systems without a great deal of study and special considerations that may result in costly modifica- tions to the system. In fact, it may not be possible to accommodate the connection on some distribution systems because of the inconvenience to other customers. Distributed Generation an... |
resistance’s of 4 , 9 and 11 . Determine the current flowing through, and the p.d. across the 9 resistor. Find also the power dissipated in the 11 resistor. The circuit diagram is shown in Fig. 5.4 Total resistance R D 4 C 9 C 11 D 24 Current I D V R D 12 24 D 0.5 A, Figure 5.4 which is the current in the 9 ... |
four feeders to its consumers. Feeder no. 1 supplies six consumers whose individual daily maximum demands are 70 kW, 90 kW, 20 kW, 50 kW, 10 kW and 20 kW while the maximum demand on the feeder is 200 kW. Feeder no. 2 supplies four consumers whose daily maximum demands are 60 kW, 40 kW, 70 kW and 30 kW, while the maximu... |
i.e. if at one end it is the clockwise direction, at the other end it should be in anticlockwise direction. 4. The minimum bending radius for cable should not be less than the value as recommended in IS 1255 and whenever possible 25% higher values should be adopted. 5. When the cable are necessarily laid and joined in ... |
neutral is isolated from the ground. Therefore, this system is also called isolated neutral system or free neutral system. Fig. 26.7 shows ungrounded neutral system. The line conductors have capacitances between one another and to ground. The former are delta-connected while the latter are star-connected. The delta-con... |
× × θ = × = 0·64 × 10–3 Wb Note that f is the flux passing through the search coil. \ Flux density, B = 3 6 0.64 10 500 10 A − − × φ = × = 1·28 Wb/m2 (ii) Within the ring, H = 120 6 1 P P N I l × = = 720 AT/m Now, B = µ0 µr H www.EngineeringBooksPdf.com Magnetic Circuits 417 \ µr = 7 0 1 28 µ 4 10 720 B H − ⋅ = π × × =... |
the procedure to be submitted by NLDC and approved by the Commission. (11) Any commercial settlement for reactive power shall be governed as per the regulatory framework specified in Annexure–4 until the same is separately notified as part of the CERC Ancillary Services Regulations. (12) If voltages are outside the lim... |
When the contacts of breaker are opened, the valve mechanism permits a high pressure SF6 gas from the reservoir to flow towards the arc interruption chamber. The fixed contact is a hollow cylindrical current carrying contact fitted with an arc horn. The moving contact is also a hollow cylinder with rectangular holes in... |
15) by equivalent delta, we have, C1 = 10 10 20 10 10 15 7 × = + + (between A and C) C2 = 10 15 30 10 10 15 7 × = + + (between B and C) C3 = 10 15 30 10 10 15 7 × = + + (between A and B) The circuit then reduces to the circuit shown in Fig. 6.33. Referring to Fig. 6.33, CAC = 20 195 25 7 7 + = = 27·86 ; CBC = 30 170 20... |
50 80 0 79 . Load in kVA at which the efficiency is maximum = x × rated kVA = 0.79 × 10 = 7.9 kVA (Ans.) (d) When p.f., cos I = 0.8 leading; sin I= sin cos–1 0.8 = 0.6 I2(fl) = 10 1000 250 40 ¥ = A V2 = E2 – I2Res cos I + I2 Xes sin I = 250 – 40 × 0.05 × 0.8 + 40 × 0.1936 × 0.6 = 250 – 1.6 + 4.6464 = 253 V % Reg = E V... |
the composite dielectric of a capacitance graded cable. The poten- tial difference V between conductor and earthed sheath is given by ; V = g dx g dx d d d D 1 2 2 2 2 2 1 1 / / / / z z + = Q x dx Q x dx d d d D 2 2 0 1 2 2 0 2 2 2 1 1 π ε ε π ε ε / / / / z z + = Q d d D d e e 2 1 1 0 1 1 2 1 πε ε ε log log + L NM O QP... |
resistance be mea- sured by the voltmeter-ammeter method as shown in Fig. 10.31 Assuming ‘perfect’ instruments, the resistance should be given by the voltmeter read- ing divided by the ammeter reading (i.e. R D V/I). However, in Fig. 10.31(a), V/I D R C ra and in Fig. 10.31(b) the current through the amme- ter is that ... |
in Fig. 21.2(a), current I0 produces the flux and is drawn in phase with the flux. The primary induced e.m.f. E1 is in phase opposition to V1 (by Lenz’s law) and is shown 180° out of phase with V1 and equal in magnitude. The secondary induced e.m.f. is shown for a 2:1 turns ratio transformer. A no-load phasor diagram for... |
the technical standards issued from time to time by the Institute of Electrical and Electronics Engineers (IEEE), United States of America; (37) “Late Payment Surcharge (LPSC)” means the monetary charge levied as per provisions of the Tariff Orders, on a consumer, for the period of delay in payment of its bills beyond ... |
D 2.2 ð 8 D 17.6 V Total internal resistance D sum of cell’s internal resistance D 0.2 ð 8 D 1.6 Z (b) When connected in parallel, total e.m.f D e.m.f. of one cell D 2.2 V Total internal resistance of 8 cells D 1 8 ð internal resistance of one cell D 1 8 ð 0.2 D 0.025 Z Problem 2. A cell has an internal resistance of 0... |
that high voltage d.c. transmission is supe- rior to high voltage a.c. transmission. Although at present, transmission of electric power is carried by a.c., there is an increasing interest in d.c. transmission. The introduction of mercury arc rectifiers and thyratrons have made it possible to convert a.c. into d.c. and... |
Routine scheduled maintenance and overhaul maintenance are specified by the manufactures. The maintenance to be carried out and their periodicity is indicated in the “Maintenance Schedule”. Manufacturer’s instructions are to be followed for special tests, if any, for that particular make of GIS substation. III. SF6 Gas... |
unit length of the line. The line has been represented in Fig. 12.9 (b) by a large number of L and C π-sections. The closing of the switch is similar to opening the valve at the end of a channel, thereby admitting water to the channel from some reservoir behind. When the valve is opened the channel does not get filled ... |
– IXq sin I or IXq cos I cot G= V + IXq sin I or tan G= IX V IX q q cos sin f f + …(vii) * For motoring action, tan T = V IX V IR q sin cos f f - - Synchronous Generators or Alternators 603 If R is neglected, E0 = V cos G+ IdXd …(viii) If R is considered, E0 = V cos G+ IR cos T + IdXd = V cos G + IqR + IdXd …(ix) *... |
the two machines I and II, respectively, Z S1 and Z S2 be the impedance/phase of two machines I and II, respectively, whereas I1 and I2 be the current supplied by the two machines, respectively. Z = load impedance/phase Now, V = E I Z E I Z S S 1 1 1 2 2 2 - = - I1 = E V Z I E V Z S S 1 1 2 2 2 - = - and I = I I E V Z ... |
fifty-one and two hundred, then the distribution utility shall arrange for,- (i) an occupational health centre having the facilities for health examination, diagnosis, treatment and maintenance of health records; Page | 93 (ii) a part-time medical officer as overall in-charge of the said centre who shall visit the prem... |
effects by shielding arranged so as not to affect the dissipation of heat from the wiring. 4.13.2.3 Where a wiring system is routed near a service liable to cause condensation (such as water, steam or gas services ) precautions shall be taken to protect the wiring system from deleterious effects. 4.13.2.4 Where a wirin... |
sequence, before an action, which would affect the scheduled supplies from ISGS to the long term customers is initiated. 13. For all outages of generation and transmission system, which may have an effect on the regional grid, all constituents shall cooperate with each other and coordinate their actions through Operati... |
D D D D ln ln ln ′ ′ ′ + + (3.44) c c a a b b Dcc Dcc Daa Daa '*/ +% + www.EngineeringBooksPdf.com ), # $ Potential of a in position 2. Va″ = 1 2 0 πε ρ ρ ρ a bb b bc bc c ba ba D r D D D D ln ln ln ′ ′ ′ + + (3.45) Similarly potential of a in posit... |
20 [1 + 0.5 × 0.006 (75 + 50)] × 23 = 9.81 × 10–3 × 20 × 1.325 × 23 = 6.2 MW Therefore, thermal generation during three intervals is PT 1 = 8 – 5.86 = 2.14 MW PT 2 = 12 – 8.23 = 3.77 MW PT 3 = 7 – 6.2 = 0.8 MW Now dF dP T T = PT + 20 = λ1 m The value of λ1 for the three intervals λ1 1 = 20 + 2.14 = 22.14, λ1 2 = 20 + 3... |
From the impedance triangle, angle D tan1 XL R D tan1 100 200 Hence the phase angle f = 26.57° lagging. Problem 10. A coil consists of a resistance of 100 and an inductance of 200 mH. If an alternating voltage, v, given by v D 200 sin 500 t volts is applied across the coil, calculate (a) the circuit impedance,... |
oil in the oil seal should be maintained. 6. After completing all the checks, ensure that all materials or tools, used for maintenance work, have been removed. All clothes and other debris must be disposed of. The transformer compound should be left in a clean and tidy condition. 7. Silica Gel Breather: In open breathi... |
This value represents the copper losses of the motor assuming the iron losses to the negligible. 5. Heat run test: This test in done to determine the temperature rise for the motor. Following three methods are generally used for conducting this test: Thermometer method Temperature detector method by embedded instru... |
receptacles and miniature circuit breakers. GFCI circuit breakers have the same outline dimensions and are installed in the load- centers in the same way as standard units. The only visible difference is that they have two built-in leads. Available in ratings from 15 to 60 A, the 15- and 20-A units are the most popular... |
are identified as LED1, LED2, etc. I Fuses: The electronic symbol for a fuse is a sine-wave shape, as shown in Fig. 1- 5e. Fuses are identified on electronic schematics as F1, F2, etc. I Ground: Electronic schematics use the same ground symbol as electrical schemat- ics, as shown in Fig. 1-5f. I Integrated circuits (IC... |
which decides the operational aspects of the Regional Grid. 59 Operating range The operating range of frequency and voltage as specified under the operating code (Chapter-5) 60 Pool Account Regional account for (i) payments regarding unscheduled-interchanges (UI Account) or (ii) reactive energy exchanges (Reactive Ener... |
sin δ0 or sin δ0 = 1 167 . = 0.6 δ0 = 36° or 0.642 radian sin δm = 10 12 . . = 0.833 or δm = 56.4° or 123.6° = 2.157 rad. δc = cos–1 0 6 2 15 0 642 0 71856 0 5534 0 23 0 809 0 48856 . ( . . ) . . . . . − − × − × = cos–1 0 9048 0 39765 0 186 0 48856 . . . . − − = cos–1 0.657 δc = 48.9°. A system h... |
must not be stopped, or because the loss of production is very expensive. 4-52 Immediate tripping is especially beneficial. The fault is quickly cleared with a minimum of damage to equipment and system. The ground cannot progress to a more severe line-to-line or multiple fault. Figure 4.15: Low-Voltage Ground-Detection... |
Dataset containing synthetically generated (by GPT-3.5 and GPT-4) short stories that only use a small vocabulary.
Described in the following paper: https://arxiv.org/abs/2305.07759.
The models referred to in the paper were trained on TinyStories-train.txt (the file tinystories-valid.txt can be used for validation loss). These models can be found on Huggingface, at roneneldan/TinyStories-1M/3M/8M/28M/33M/1Layer-21M.
Additional resources: tinystories_all_data.tar.gz - contains a superset of the stories together with metadata and the prompt that was used to create each story.
TinyStoriesV2-GPT4-train.txt - Is a new version of the dataset that is based on generations by GPT-4 only (the original dataset also has generations by GPT-3.5 which are of lesser quality). It contains all the examples in TinyStories.txt which were GPT-4 generated as a subset (but is significantly larger).
Evaluation_prompts.yaml: List of prompts used to evaluate our models (see paper)
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