What is the meaning of Star winding/ Delta winding?

What is the meaning of Star winding/ Delta winding?
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1 Answer

Answer :

Refer Dennis T Hall
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Related questions

What is star / delta ?*

Description : What is star / delta ?*

Last Answer : In star VL = √3 VΦ In delta VL = VΦ

Is the alternator connected star or delta

Description : Is the alternator connected star or delta

Last Answer : Look up in Dennis T Hall. Also in your ship ask E/O. Normally star.

If a motor is wound star and you want to change to delta what should you do?

Description : If a motor is wound star and you want to change to delta what should you do?

Last Answer : Open the terminal connection box. Remove the shorting link connecting the common connection (star) point of A2, B2 and C2. With the 3 phase windings marked A1A2, B1B2, C1C2, connect A2 to B1, B2 to C1 and C2 to A1.

Is the ship's alternator Star wound or Delta wound?

Description : Is the ship's alternator Star wound or Delta wound?

Last Answer : Refer Dennis T Hall

What are the advantages of the use of frequency converter instead of star-delta or soft starter?

Description : Can you guys explain the advantages of frequency converter against the star delta or soft starter?

Last Answer : ¬Soft starters  A soft starter is, as you would expect, a device which ensures a soft starting of a motor. A softstarter has different characteristics to the other starting ... at rated current from zero to full speed. Frequency converters are becoming cheaper all the time.

In testing a three-phase delta winding for an open circuit using a megohmmeter, you must ______________. A. test each phase with all connections intact B. measure the voltage across the open connections while testing C. test the windings as parallel groups to avoid short circuiting D. open the delta-connections to avoid shunting the phase being tested

Description : In testing a three-phase delta winding for an open circuit using a megohmmeter, you must ______________. A. test each phase with all connections intact B. measure the voltage across the open ... groups to avoid short circuiting D. open the delta-connections to avoid shunting the phase being tested

Last Answer : Answer: D

32 With S2 closed and S1 open, the current waveform in the delta winding will be [GATE 2009] A. a sinusoidal at fundamental frequency B. flat-topped with third harmonic C. only third-harmonic D. none of these

Description : 32 With S2 closed and S1 open, the current waveform in the delta winding will be [GATE 2009] A. a sinusoidal at fundamental frequency B. flat-topped with third harmonic C. only third-harmonic D. none of these

Last Answer : C. Only third harmonic

Electrical fault between two windings of same phase of a generator having double star winding can be

Description : Electrical fault between two windings of same phase of a generator having double star winding can be detected by the following protection in a generator:

Last Answer : Electrical fault between two windings of same phase of a generator having double star winding can be detected by the following protection in a generator: inter turn fault protection

What is the meaning of a normally open contact?

Description : What is the meaning of a normally open contact?

Last Answer : The contact is open in the normal (de-energised condition).

What is the meaning of residual magnetism?

Description : What is the meaning of residual magnetism?

Last Answer : Residual magnetism is a property in which certain amount of excitation remains back in the conductor even after the removal of the magnets.

What is the meaning of excitation in an alternator?

Description : What is the meaning of excitation in an alternator?

Last Answer : An electric generator or electric motor consists of a rotor spinning in a magnetic field. The magnetic field may be produced by permanent magnets or by field coils. In the case of a machine ... rotor. The process of generating a magnetic field by means of an electric current is called excitation.

What is meaning of short circuit?

Description : What is meaning of short circuit?

Last Answer : A short circuit occurs when conductors are connected (shorted) together by a fault. This is normally phase to phase fault due to failure of insulation by something cutting the wires, fires, etc.

What is the meaning of overload?

Description : What is the meaning of overload?

Last Answer : An overload is a current over and above the normal load current (over the load). In other words greater than the original design current. This can be a momentary overload such as the starting ... such as plugging in too many appliances at once or a motor that has faulty bearings or gets jammed

What is the meaning of ACB, MCCB, NFB?

Description : What is the meaning of ACB, MCCB, NFB?

Last Answer : Air circuit breaker for 400V higher current ratings. Moulded case circuit breaker for 400V medium current ratings. No Fuse Breaker – 75 A capacity

What is the meaning of earthing in a ship?

Description : What is the meaning of earthing in a ship?

Last Answer : Ask E/O

What is the meaning of saying I and V are in phase?

Description : What is the meaning of saying I and V are in phase?

Last Answer : The angle between the I and V waveforms is zero which means the load is purely resistive.

What is the meaning of power factor?

Description : What is the meaning of power factor?

Last Answer : Power factor is the cosine of the angle between voltage and current waveform.

What is the meaning of preferential trip? Why is it provided

Description : What is the meaning of preferential trip? Why is it provided

Last Answer : Preferential trip is a kind of electrical arrangement on ship which is designed to disconnect the non-essential circuit i.e. non-essential load from the main bus bar in case of partial failure or overload ... gear) and trips the non essential loads (like AC and galley) and is a safety feature.

Write the formula from Star to Delta ?

Description : Write the formula from Star to Delta ?

Last Answer : Answer : Dividing the product of the resistors connected to the star by dividing the resistors of the opposite arm by taking two together, the quotient is equal to the value of each resistor connected.

What equipment are star delta starters used in?

Description : What equipment are star delta starters used in?

Last Answer : Star Delta starter is used to start the AC motors with rating generally higher than 11 kw, depending upon the type of load.

If P is the power of a star connected system then what will be power of an equivalent delta connected system? A..P B. 3P C. P/3 D. None of the above

Description : If P is the power of a star connected system then what will be power of an equivalent delta connected system? A..P B. 3P C. P/3 D. None of the above

Last Answer : Ans: A

Disadvantages of Star-Delta Starting of Induction motor?

Description : Disadvantages of Star-Delta Starting of Induction motor?

Last Answer : In Star-Delta starting induction motor stator is connected in star connection for starting after picking up speed it is connected to delta connection. When induction motor is connected in star connection ... . This also results in reduced starting torque (1/3 times compared to delta connection).

What advantage has the star connection over the delta connection ?

Description : What advantage has the star connection over the delta connection ?

Last Answer : A. Each star connection transformer is wound for only 57.7% of line voltage . In hv transmission, this admits of much smaller transformer being built for high voltage than possible with delta connection, because of less insulation.

Why Delta Star Transformers are used for Lighting Loads?

Description : Why Delta Star Transformers are used for Lighting Loads?

Last Answer : A. For lighting loads, neutral conductor is must and hence the secondary must be star winding.This lighting load is always unbalanced in all three phases. To minimize the current unbalance in the primary we use delta winding in the primary. So delta / star transformer is used for lighting loads.

What is the difference between delta-delta, delta-star transformer?

Description : What is the difference between delta-delta, delta-star transformer?

Last Answer : A. Delta-delta transformer is used at generating station or a receiving station for Change of Voltage (i,e) generally it is used where the Voltage is high & Current is low whereas Delta-star ... star neutral is taken as a return path and this configuration is used for Step down voltage phenomena.

Why Delta Star transformer Are Used For Lighting Loads?

Description : Why Delta Star transformer Are Used For Lighting Loads?

Last Answer : For lighting loads, neutral conductor is must and hence the secondary must be star winding. and this lighting load is always unbalanced in all three phases. To minimize the current unbalance in the primary we use delta winding in the primary. So delta / star trformer is used for lighting loads.

Why input transformer of PUPS module 1 is delta-delta and module 2 is delta-star?

Description : Why input transformer of PUPS module 1 is delta-delta and module 2 is delta-star?

Last Answer : With the help of this arrangement, combined DC output from both chargers is equivalent to that from a 12-pulse rectifier. Advantage of 12-pulse rectifier is that the mains current is fairly close ... phase angle difference 30-degree between module 1 output and module 2 output give 12-pulse output. 

Why delta – delta CT’s are used for star – star transformer differential protection?

Description : Why delta – delta CT’s are used for star – star transformer differential protection?

Last Answer : Say primary neutral is not solidly earthed. Then for any earthfault on secondary terminal, the primary current distribution is so for external fault, the differential is likely to operate if sequence current ... into relay. The 2:1:1 distribution is possibly only for core type or delta tertiary.

State the voltage and current relation in star and delta connection.

Description : State the voltage and current relation in star and delta connection. 

Last Answer : In star connection line current is equal to the phase current and line voltage is √3 times that of phase voltage. In delta connection line voltage is equal to the phase voltage and line current is √3 times that of phase current. 

What are the value of voltage and current in star connection and in delta connection?

Description : What are the value of voltage and current in star connection and in delta connection?

Last Answer : Star connection a. IL = IPh. b. VL = √3 VPh. ∴ VPh = VL/√3. Note: in star connection we are getting neutral point and we can able to measure the phase as well as line voltage. Delta connection a. VL = VPh. b. IL = √3 IPh. ∴ IPh = IL/√3.

What are the advantages of star-delta starter with induction motor?

Description : What are the advantages of star-delta starter with induction motor?

Last Answer : The main advantage of using the star delta starter is reduction of current during the starting of the motor. Starting current is reduced to 3-4 times of current of Direct online starting Hence the starting current is reduced , the voltage drops during the starting of motor in systems are reduced

Why Delta Star Transformers are used for Lighting Loads?

Description : Why Delta Star Transformers are used for Lighting Loads?

Last Answer : For lighting loads, neutral conductor is must and hence the secondary must be star winding and this lighting load is always unbalanced in all three phases.  To minimize the current unbalance in the primary we use delta winding in the primary So delta / star transformer is used for lighting loads.

Why star delta starter is preferred with induction motor?

Description : Why star delta starter is preferred with induction motor?

Last Answer : Star delta starter is preferred with induction motor due to following reasons: Starting current is reduced 3-4 times of the direct current due to which voltage drops and hence it causes less ... caused. In addition, starting torque is increased and it prevents the damage of motor winding.

In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltage in the two cases. (A) delta side lags by -30°. (B) star side lags by -30°. (C) delta side leads by 30°. (D) star side leads by -30°.

Description : In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltage in the two cases. (A) delta side lags by -30°. (B) star side lags by -30°. (C) delta side leads by 30°. (D) star side leads by -30°.

Last Answer : Ans: C This is vector group and has +30° displacement. Therefore, delta side leads by +30°.

Draw the star and delta connection. State any one conversion formula.

Description : Draw the star and delta connection. State any one conversion formula.

Last Answer : star and delta connection

Convert the delta network into equivalent star network.

Description : Convert the delta network into equivalent star network.

Last Answer : Delta to start network R1 = 4x6/ 4+6+2 = 24/12 =2/1= 2Ω R2 = 2x6/ 4+6+2 = 12/12= 1 = 1Ω R3 = 4x 2/ 4+6+2 = 8/12= 2/3= 0.66Ω

Derive an expression for delta to star transformation.

Description : Derive an expression for delta to star transformation. 

Last Answer : For delta network the resistance between the terminals 1 and 2 consists of R12 in parallel with  (R23+R31) Hence ,the resistance between the terminals 1 and 2 is In case of star network the ... equation( ii) from( i),we get Adding equations (iii) and( iv),we have 

Calculate the equivalent resistance between A & B using star-delta conversion

Description : Calculate the equivalent resistance between A & B using star-delta conversion

Last Answer : Solution :  Converting Inner star in to delta-  Resistances 4 and 6 are in parallel in all branch so

Develop the control circuit for star-delta starter used for starting a 3 ∅ induction motor.

Description : Develop the control circuit for star-delta starter used for starting a 3 ∅ induction motor.

Last Answer : Control Circuit for Star-Delta Starter: 1) Automatic Star-Delta Starter: OR 2) Semi- automatic Star-Delta Starter:

Delta to Star Conversion Example

Description : Delta to Star Conversion Example

Last Answer : Delta to Star Conversion Example

Wye (Star) to Delta Conversion

Description : Wye (Star) to Delta Conversion

Last Answer : Wye (Star) to Delta Conversion

Star to delta conversion examples

Description : Star to delta conversion examples

Last Answer : Star to delta conversion example 1

Draw and explain star delta starter for 3 phase induction motor

Description : Draw and explain star delta starter for 3 phase induction motor

Last Answer : Star Delta Starter for 3 Phase Induction Motor:  Diagram Explanation: The stator winding of the motor which is designed for delta operation is connected in star during starting ... which connects stator windings in delta connection. Now each stator phase gets full line voltage VL.

for Delta-Star connection of 3-phase transformer: i) Draw the connection diagram ii) List any two advantages of this connection iii) State its area of application.

Description : for Delta-Star connection of 3-phase transformer: i) Draw the connection diagram ii) List any two advantages of this connection iii) State its area of application. 

Last Answer : Disadvantages: i) In this type of connection, the secondary voltage is not in phase with the primary. Hence it is not possible to operate this connection in parallel with star-star or delta-delta ... iv) As line current is equal to phase current the conductor size of winding should be large. 

Describe the power and control circuit for automatic Star-Delta starter for 3-phase induction motor.

Description : Describe the power and control circuit for automatic Star-Delta starter for 3-phase induction motor.

Last Answer : Power circuit: Control circuit: 

Compare star and Delta Connection.

Description : Compare star and Delta Connection.

Last Answer : Compare Star and Delta connected system:  Star connected system Delta connected system   In STAR connection, the starting or finishing ends (Similar ends) of three coils are connected together to form the ... VPH Line Current is √3 times of Phase Current. i.e. IL = √3 IPH

A three-phase transformer, connected in star-delta, is composed of three single-phase transformers, each

Description : A three-phase transformer, connected in star-delta, is composed of three single-phase transformers, each rated 127/ 13.2 kV. The line-to-line voltage ratio for the three-phase transformer is: A) 220 / 13.2 kV B) 127 / 13.2 kV C) 127 / 220 kV D) 220 / 220 kV

Last Answer : A three-phase transformer, connected in star-delta, is composed of three single-phase transformers, each rated 127/ 13.2 kV. The line-to-line voltage ratio for the three-phase transformer is: 220 / 13.2 kV 

Consider the following statements: Star delta starter is used in 3-phase induction motor

Description : Consider the following statements: Star delta starter is used in 3-phase induction motor because it  1. Prevents heating of the motor winding  2. Ensures permissible minimum starting current  3. Is regulated by electricity ... and 4 are correct (c) 1, 3 and 4 are correct (d) 1 and 2 are correct 

Last Answer : Consider the following statements: Star delta starter is used in 3-phase induction motor because it  1. Prevents heating of the motor winding  2. Ensures permissible minimum starting current  3. Is regulated by ... and 4 are correct (c) 1, 3 and 4 are correct (d) 1 and 2 are correct 

If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded

Description : If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then  (A) zero sequence currents are present on both sides of the transformer  (B) ... side  (D) zero sequence currents are present on the primary side but not on the secondary side

Last Answer : If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then zero sequence currents are absent on both sides of the transformer 

A 4000 kVA, 11 kV/132 kV delta-star connected 3-phase transformer has reactance, x1 = 0.12 p.u.

Description : A 4000 kVA, 11 kV/132 kV delta-star connected 3-phase transformer has reactance, x1 = 0.12 p.u. The actual value of x1 referred to the low voltage side is (A) 0.85 Ω (B) 3.63 Ω (C) 36.3 Ω (D) 252 Ω

Last Answer : A 4000 kVA, 11 kV/132 kV delta-star connected 3-phase transformer has reactance, x1 = 0.12 p.u. The actual value of x1 referred to the low voltage side is 3.63 Ω