7. The ampacity of a transformer circuit conductors shall not be less than the transformer's FLA taken from the transformer nameplate multiplied by what factor and what is the trade name given to this factor?

7. The ampacity of a transformer circuit conductors shall not be less than the transformer's FLA taken from the transformer nameplate multiplied by what factor and what is the trade name given to this factor?

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.57P: A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when...

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Similar questions

The nameplate on a transformer will indicate whether or not it is a Class 2 transformer. (True) (False) (Circle the correct answer.)
A single-phase l0-kVA,2300/230-volt,60-Hz two-winding distribution transformer is connected as an autotransformer to step up the voltage from 2300 to 2530 volts (a) Draw a schematic diagram of this arrangement, showing all voltages and currents when delivering full load at rated voltage. (b) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the rated values as a two-winding transformer. How much of this kVA rating is transformed by magnetic induction? (C) The following data are obtained from tests carried out on the transformer when it is connected as a two-winding transformer: Open-circuit test with the low-voltage terminals excited: Applied voltage =230V, input current =0.45A, input power =70W. Short-circuit test with the high-voltage terminals excited: Applied voltage =120, input current =4.5A, input power =240W. Based on the data, compute the efficiency of the autotransformer corresponding to full load, rated voltage, and 0.8 power factor lagging. Comment on why the efficiency is higher as an autotransformer than as a two-winding transformer.
An open-delta three-phase transformer system has one transformer center-tapped to provide a neutral for single-phase voltages. If the voltage from line to center tap is 277 V, what is the high-leg voltage?
A single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters: Resistance of the 2400-V winding: R1=0.75 Resistance of the 240-V winding: R2=0.0075 Leakage reactance of the 2400-V winding: X1=1.0 Leakage reactance of the 240-V winding: X2=0.01 Exciting admittance on the 240-V side =0.003j0.02S (a) Draw the equivalent circuit referred to the high-voltage side of the transformer. (b) Draw the equivalent circuit referred to the low-voltage side of the transformer. Show the numerical values of impedances on the equivalent circuits.
An infinite bus, which is a constant voltage source, is connected to the primary of the three-winding transformer of Problem 3.53. A 7.5-MVA,13.2-kV synchronous motor with a sub transient reactance of 0.2 per unit is connected to the transformer secondary. A5-MW,2.3-kV three-phase resistive load is connected to the tertiary Choosing a base of 66 kV and 15 MVA in the primary, draw the impedance diagram of the system showing per-unit impedances. Neglect transformer exciting current, phase shifts, and all resistances except the resistive load.
Using the method shown in this unit, what is the approximate short-circuit current available at the terminals of a 50-kVA single-phase transformer rated 120/240 volts? The transformer impedance is 1%. a. Line-to-line b. Line-to-neutral
For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the rated voltage on the other winding? (a) Yes (b) No
A single-phase two-winding transformer rated 90MVA,80/120kV is to be connected as an autotransformer rated 80/200kV. Assume that the transformer is ideal. (a) Draw a schematic diagram of the ideal transformer connected as an autotransformer. showing the voltages, currents, and dot notation for polarity. (b) Determine the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the rated values as a two-winding transformer. How much of the kA rating is transferred by magnetic induction?
A 4.6-kVA, 308 / 155 -volt distribution transformer has the following equivalent resistance and leakage-reactance values referred to the primary: rep = 1.5 ohm; xep = 7.5 ohms. The core losses of this transformer amount to 500 watts. If this transformer is operating at full-load unity power factor, what is its percent efficiency?
A 4.2-kVA, 237 / 164 -volt distribution transformer has the following equivalent resistance and leakage-reactance values referred to the primary: rep = 1.5 ohm; xep = 8.5 ohms. If this transformer is operating at full-load unity power factor, what will be the percent voltage regulation of this transformer?
Solve the following problems with complete solutions and units usingtwo(2) decimal digits. 1. A 25-kVA, 1-phase transformer, 2,200 volts to 220 volts, has a primaryresistance of 1.0 Ω and a secondary resistance of 0.01 Ω. Find theequivalent secondary resistance and the full-load efficiency at 0.8power factor if the iron loss of the transformer is 80% of the full-loadcopper loss.
I ONLY NEED B PART III ANSWERED. NO OTHER PART OF THE QUESTION. You have been hired as an engineering consultant to diagnose an overheating and low output voltage problem with a three-phase transformer. The service technicians informed you that the transformer has a solid nickel core, insulated aluminum windings and a single phase of the transformer is rated at 50 kVA, 6900/400 V, 60 Hz. The transformer cannot be disconnected for open and short circuit testing and only the input lines and output outlets are accessible for current and voltage measurements. (a) The following measurements were taken after and during working hours when all the electrical devices were off and on,respectively. No load condition: Input Phase Current = 3∠−60°A, Output Voltage = 400∠0°V Load condition: Input Phase Current = 8.45∠−37.35°A, Output Voltage = 370∠−0.64°V Assuming the input voltage is maintained at its rated value, calculate the modelled internal parameters Ro, Xm, Reqand Xeq of the transformer…