Is the alternator connected star or delta

Is the alternator connected star or delta
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Answer :

Look up in Dennis T Hall. Also in your ship ask E/O. Normally star.
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Related questions

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 is star / delta ?*

Description : What is star / delta ?*

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

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.

What is the meaning of Star winding/ Delta winding?

Description : What is the meaning of Star winding/ Delta winding?

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.

What are the excitation methods used in an alternator?*

Description : What are the excitation methods used in an alternator?*

Last Answer : Rotary : Using rotating diode rectifiers, primary exciter and main exciter. Static : Excitation given by brushes and slip rings.

Even though the main engine runs at varying speeds, how does the alternator maintain constant frequency?

Description : Even though the main engine runs at varying speeds, how does the alternator maintain constant frequency?

Last Answer : By use of thyristor controlled frequency (rpm) converters.

What is a brush less alternator?

Description : What is a brush less alternator?

Last Answer : A brushless alternator is composed of two sections: main alternator and the smaller exciter. The exciter has stationary field coils and a rotating armature (power coils). The main alternator ... has a rotating field as described above and a stationary armature (power generation windings).

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.

Why is it necessary that incoming alternator frequency is more than bus bar?

Description : Why is it necessary that incoming alternator frequency is more than bus bar?

Last Answer : Prior to paralleling alternators together, the frequency of the incoming alternator is made slightly higher. This is to ensure that the incoming generator will take some of the bus load. If the incoming ... onto the bus. If this happens it is possible to cause other generators to trip off line.

Why are motor ratings given in KW and that of alternator and transformer given in KVA?

Description : Why are motor ratings given in KW and that of alternator and transformer given in KVA?

Last Answer : kW is the output mechanical power of a motor and is expressed in kW. kVA is the net (apparent) power input to the transformer. This input power is the output + losses. kW = kVA x system power factor

Size of V belts used for 25KW Alternator a. C121 c. C122 b. C123 d. C124

Description : Size of V belts used for 25KW Alternator a. C121 c. C122 b. C123 d. C124

Last Answer : c. C122

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

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°.

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 

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

Three resistances of 3 Ω each are connected in delta. The value of the resistances in the equivalent star is ...

Description : Three resistances of 3 Ω each are connected in delta. The value of the resistances in the equivalent star is : (A) 27 (B) 9 (C) 1.5 (D) 1 Ω

Last Answer : 9

Moving coil in dynamometer wattmeter connected a) In series with fixed coil b) Across supply c) In series with load d) Across load

Description : Moving coil in dynamometer wattmeter connected a) In series with fixed coil b) Across supply c) In series with load d) Across load

Last Answer : Ans: Across supply

A galvanometer of 65 Ω resistance gives full scale deflection with 4 mA current. In order to convert it into ammeter, the range of 10 A is connected with it, the shunt resistance should be a) 0.1 Ω b) 0.2 Ω c) 0.06 Ω d) 0.03 Ω

Description : A galvanometer of 65 Ω resistance gives full scale deflection with 4 mA current. In order to convert it into ammeter, the range of 10 A is connected with it, the shunt resistance should be a) 0.1 Ω b) 0.2 Ω c) 0.06 Ω d) 0.03 Ω

Last Answer : d) 0.03 Ω

Three resistors of resistance R are connected in various ways, which of the following cannot be obtained? a. 3R ohm b. 2R/4 ohm c. R/3 ohm d. 2R/3 ohm

Description : Three resistors of resistance R are connected in various ways, which of the following cannot be obtained? a. 3R ohm b. 2R/4 ohm c. R/3 ohm d. 2R/3 ohm

Last Answer : b. 2R/4 ohm

All electrical appliances are connected in parallel to each other between the main line and neutral wire to get a. same current b. same current and potential difference c. different current but same potential difference d. different current and potential differences

Description : All electrical appliances are connected in parallel to each other between the main line and neutral wire to get a. same current b. same current and potential difference c. different current but same potential difference d. different current and potential differences

Last Answer : c. different current but same potential difference

A neon flashlight cell with an emf of 1.5V gives a current of 15A when connected directly to an ammeter of resistance 0.04?. Internal resistance of the cell is a. 0.0004? b. 0.06? c. 0.10? d. 0.13?

Description : A neon flashlight cell with an emf of 1.5V gives a current of 15A when connected directly to an ammeter of resistance 0.04?. Internal resistance of the cell is a. 0.0004? b. 0.06? c. 0.10? d. 0.13?

Last Answer : b. 0.06?

Three bulbs are rating 40W 60W and 100W designed to work on 220V mains. Which bulb will burn most brightly if they are connected in series across 220 V mains? a. 40 W bulb b. 60 W blub c. 100 W blub d. all will burn equally brightly

Description : Three bulbs are rating 40W 60W and 100W designed to work on 220V mains. Which bulb will burn most brightly if they are connected in series across 220 V mains? a. 40 W bulb b. 60 W blub c. 100 W blub d. all will burn equally brightly

Last Answer : a. 40 W bulb

When 2,4 and 6 ohms resistor are connected in parallel their resultant equivalent resistance will be A. 12ohm b. 11/12ohm C. 12/11ohm d. None

Description : When 2,4 and 6 ohms resistor are connected in parallel their resultant equivalent resistance will be A. 12ohm b. 11/12ohm C. 12/11ohm d. None

Last Answer : C. 12/11ohm

Three equal resistors connected in series with a source of e m f together dissipate 10 W of power each. What will be the power dissipated if the same resistors are connected in parallel across the same source of e m f? a. 40 W b. 90W c. 100W d. 120W

Description : Three equal resistors connected in series with a source of e m f together dissipate 10 W of power each. What will be the power dissipated if the same resistors are connected in parallel across the same source of e m f? a. 40 W b. 90W c. 100W d. 120W

Last Answer : b. 90W

In the illustration, the signal from the device connected to terminals 18 and 19 is __________. EL-0046 A. prime mover speed feedback B. loss of control alarm when comparing with the input signal from the resistor at the top of the speed sensing circuit card C. hall effect current to detect slip between the prime mover and the alternator D. to shut down the prime mover if overspeeding

Description : In the illustration, the signal from the device connected to terminals 18 and 19 is __________. EL-0046 A. prime mover speed feedback B. loss of control alarm when comparing with the input signal ... slip between the prime mover and the alternator D. to shut down the prime mover if overspeeding

Last Answer : Answer: A

How does increase in steam input of the Alternator connected to infinite bus-bars affect this operation?

Description : How does increase in steam input of the Alternator connected to infinite bus-bars affect this operation?

Last Answer : KW output power of alternator increase with increase in steam input keeping excitation constant.

How does increase in excitation of the Alternator connected to infinite bus-bars affect this operation?

Description : How does increase in excitation of the Alternator connected to infinite bus-bars affect this operation?

Last Answer : Increase in excitation level of the synchronous generator will effectively increase the reactive power supplied by the generator keeping steam input constant.

An Alternator is found to have its terminal voltage on load condition more than that on no load. What is the nature of the load connected?

Description : An Alternator is found to have its terminal voltage on load condition more than that on no load. What is the nature of the load connected?

Last Answer : The nature of the load is of leading power factor , load consisting of resistance and capacitive reactance.

at the terminal of a three-phase 6.6Kv alternator a load R=200 ohm is connected between two-phase and the third phase is opened. Z1=z2=5 ohm Zo=2 find out the fault current .

Description : at the terminal of a three-phase 6.6Kv alternator a load R=200 ohm is connected between two-phase and the third phase is opened. Z1=z2=5 ohm Zo=2 find out the fault current .

Last Answer : 32A

When an alternator connected to the bus-bar is shut down the bus-bar voltage will (a) fall (b) rise (c) remain unchanged (d) none of the above

Description : When an alternator connected to the bus-bar is shut down the bus-bar voltage will (a) fall (b) rise (c) remain unchanged (d) none of the above

Last Answer : (c) remain unchanged

The driving power from the prime-mover driving the alternator is lost but the alternator remains connected

Description :  The driving power from the prime-mover driving the alternator is lost but the alternator remains connected to the supply network; the field supply also remains on. The alternator will: A) ... as a synchronous motor but will rotate in a reverse direction to that corresponding to generator action 

Last Answer : The driving power from the prime-mover driving the alternator is lost but the alternator remains connected to the supply network; the field supply also remains on. The alternator will: behave as a synchronous motor and will rotate in the same direction

A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit

Description : A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive-sequence, negative-sequence and zero-sequence impedances of the alternator are j0.1, j0.1 and j0.04 respectively. The neutral of ... the fault is  (A) 513.8 V (B) 889.9 V (C) 1112.0 V (D) 642.2 V

Last Answer : A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive-sequence, negative-sequence and zero-sequence impedances of the alternator are j0.1, ... line. The voltage of the alternator neutral with respect to ground during the fault is 642.2 V

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.

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.

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