What is the purpose of static starter? How current setting adopted?

What is the purpose of static starter? How current setting adopted?
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Answer :

The static starter limits the starting current of the motor to 2.5 times the motor rated current instead of 6 times the rated current. If the motor is directly on UPS, the UPS fuse will blow, since the UPS cannot supply so much starting current. Hence the static starter is set to limit the starting current. This is achieved by firing angle control of back to back thyristor. 
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Related questions

Before servicing the device indicated as 'A' in panels #1 and #3 of the illustration, the device labeled 'CT' must __________. EL-0003 A. have the disconnected leads taped to prevent short circuiting. B. only be connected to multimeter on the ammeter setting C. be short circuited D. have one lead grounded to discharge static electricity for the prevention of damage to electronic components

Description : Before servicing the device indicated as 'A' in panels #1 and #3 of the illustration, the device labeled 'CT' must __________. EL-0003 A. have the disconnected leads taped to prevent ... D. have one lead grounded to discharge static electricity for the prevention of damage to electronic components

Last Answer : Answer: C

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Description : The purpose of the bias winding in figure 'B' shown in the illustration is for ____________. EL-0091 A. changing the direction of current in the control winding B. setting the operating point of the ... use of either AC or DC in the load circuit D. changing the direction of current through the load

Last Answer : Answer: B

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Description : Motor starter or controller contacts may become welded together if the contacts _____________. A. open too quickly and arc B. close under excessive pressure C. open or close too quickly D. close under excessive starting current

Last Answer : Answer: D

If the contacts of a motor starter or controller fail to drop out when the 'stop' button is depressed the ____________. A. contacts are carrying excessive current B. contacts have become welded together C. shading coil is broken D. shading coil is loose

Description : If the contacts of a motor starter or controller fail to drop out when the 'stop' button is depressed the ____________. A. contacts are carrying excessive current B. contacts have become welded together C. shading coil is broken D. shading coil is loose

Last Answer : Answer: B

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Description : The rotor slots of a repulsion-type motor are generally skewed (placed nonparallel to the rotor axis) to _________. A. produce a constant starting torque B. permit a greater air gap with the starter C. permit a smaller air gap with the starter D. reduce eddy current losses

Last Answer : Answer: A

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Description : An across-the-line starter is typically used for which of the following applications? A. Reduced-current starting of large motors B. Low torque starting of small motors C. Low resistance starting of DC motors D. Full-voltage starting of motors

Last Answer : Answer: D

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Last Answer : Answer: A

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Last Answer : (c) 2 and 3 only

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Description : The electrical schematic shown in the illustration represents a/an ____________. EL-0017 A. across-the-line starter B. primary-resistor starter C. autotransformer starter D. part-winding starter

Last Answer : Answer: A

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Description : When a fluorescent lamp fails to light, the trouble can be in the _____________. A. lamp B. starter C. ballast D. all of the above

Last Answer : Answer: D

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Description : To check the three line fuses of a three-phase system consisting of a three-phase motor, you must _____________. A. place the starter in the 'stop' position B. make sure the motor is operating at full ... leads across the 'hot' ends of the fuses D. place the leads across the bottom ends of the fuses

Last Answer : Answer: A

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Description : When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately, or the resultant flashing may _____________. A. blow the lamp's circuit breaker B. explode, ... fly in all directions C. short circuit the ballast transformer D. damage the starter and the ballast

Last Answer : Answer: D

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Last Answer : Answer: B

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Last Answer : Answer: B

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Last Answer : Answer: B

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Last Answer : Answer: D

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Last Answer : Answer: D

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Description : In a faceplate-type motor starter, the starting arm is held in the 'OFF' position by a/an _____________. A. cotter pin B. magnet C. electrical circuit D. strong spring

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Description : Difference Between A Four Point Starter And Three Point Starter?

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What is the necessity of starter?

Description : What is the necessity of starter?

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What are the types of DC motor starter?

Description : What are the types of DC motor starter?

Last Answer : a. DC two point starter for series motor. b. DC three point starter for shunt motor. c. DC four point starter for compound motor.

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Description : What is the necessity of DC motor starter?

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Difference between a four point starter and three point starters?

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

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When was the ‘International Convention on the Elimination of All Forms of Racial Dis-crimination’ adopted and to what purpose? -SST 10th

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Last Answer : The General Assembly adopted the International Convention on the Elimination of All Forms of Racial Discrimination' in December, 1965. The convention came into force in 1969 and as its name suggests ... to Racial Discrimination in all its forms. It was mandatory for the States who ratified it.

Farmers also adopted sprinkaler system for purpose. A) Commercial. C) Domestic

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Description : Why wound rotor construction is adopted?

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Why ungrounded 250V DC system adopted in our system?

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Description : What are the logic’s adopted in barring gear motor?

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How neutral grounding adopted?

Description : How neutral grounding adopted? 

Last Answer : For above 3.3 kV and below 22 kV resistance grounding is preferred. In this voltage level capacitive ground current is not large, so reactance grounding is not used. For below 3.3 kV ... in transmission lines, generators etc. to neutralize capacitive current by adding reactive current.  

What type of motor starting adopted in MCC?

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Which of the following statements is correct for any closed loop system ? (a) All the co-efficients can have zero value (6) All the co-efficients are always non-zero (c) Only one of the static error co-efficients has a finite non-zero value (d) None of the above

Description : Which of the following statements is correct for any closed loop system ? (a) All the co-efficients can have zero value (6) All the co-efficients are always non-zero (c) Only one of the static error co-efficients has a finite non-zero value (d) None of the above

Last Answer : Ans: C

A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected, this is caused by _____________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. capacitors inside the meter storing charges

Description : A switchboard ammeter indicates a reading slightly above 'zero' when the leads are disconnected, this is caused by _____________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. capacitors inside the meter storing charges

Last Answer : Answer: A

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Description : In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded ... magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Last Answer : Answer: B

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Description : In which of the situations listed will a megohmmeter give the most accurate readings? A. While the machine is in operation. B. While the machine is discharging static electricity. C. Immediately prior to ... machine. D. When the machine has been shut down and grounded for a period of 15 minutes.

Last Answer : Answer: D

An ammeter reads slightly above 'zero' when its leads are disconnected, this is a result of ___________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. resistors inside the meter storing charges

Description : An ammeter reads slightly above 'zero' when its leads are disconnected, this is a result of ___________. A. mechanical misalignment of the meter pointer B. a poor ground for the meter case C. static electricity in the air D. resistors inside the meter storing charges

Last Answer : Answer: A