What is E/F current limit for SUT and UT?

What is E/F current limit for SUT and UT?
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1 Answer

Answer :

400a limited by 10 ohms resistor.  
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Related questions

Purpose of standby E/F protection in SUT/UT?

Description : Purpose of standby E/F protection in SUT/UT? 

Last Answer : Back up for LV winding, LV neutral CT- CDG 12 – resistance earthing – relay set high time delay to discriminate with LV feeder and trip transformer if sustained E/F, also protects neutral earthing resistor.

Why UT, SUT secondary is rated for 6.9kV where as bus voltage is 6.6kV?

Description : Why UT, SUT secondary is rated for 6.9kV where as bus voltage is 6.6kV? 

Last Answer : The no load secondary 6.9kV voltage level adequately takes into account voltage drop during loaded condition to cater station buses at 6.6kV level. 

Why REF is provided in the LV side of SUT and UT?

Description : Why REF is provided in the LV side of SUT and UT? 

Last Answer : The LV sides of the two transformers are earthed through the resistance. This will limit the flow of current in case of LV earth fault. Hence the differential protection may not act for a LV earth fault. Hence ref protection is provided. 

Why the neutral is earthed through earthing resistance in case of UT and SUT?

Description : Why the neutral is earthed through earthing resistance in case of UT and SUT? 

Last Answer : This is done to limit the earth fault current.  

What is the vector group of GT, UT, SUT?

Description : What is the vector group of GT, UT, SUT?

Last Answer : Yd11 Dy1 Yy0 

During unit operation, can we parallel UT & SUT continuously?

Description : During unit operation, can we parallel UT & SUT continuously?

Last Answer : No, due to switchgear limitation.  

What are the protections for SUT?

Description : What are the protections for SUT? 

Last Answer : a) Over current protection for phase and earth fault b) Differential protection c) HV and LV restricted earthfault protection  d) HV side directional back up over current protection for phase ... protection f) Over fluxing protection g) Buchholz and high oil, winding temperature protection. 

Why vector group of SUT is chosen as Yn-Yo-Yo?

Description : Why vector group of SUT is chosen as Yn-Yo-Yo?

Last Answer : To facilitate momentary paralleling of SUT with UT on 6.6kV buses.  

Why twin secondary SUT?

Description : Why twin secondary SUT? 

Last Answer : As per is, the rating single secondary power transformer is limited to 25MVA (6.6 kV) or 40 MVA (11 kV), in order to limit the 3 phase symmetrical fault level with in 26-40 kA (contribution from grid and local machines) 

During unit operation, can we parallel 2 SUT?

Description : During unit operation, can we parallel 2 SUT? 

Last Answer : No, due to switchgear limitation. 

What is the coverage of differential protection for SUT?

Description : What is the coverage of differential protection for SUT?

Last Answer : Covers from 230 kV bushing to 6.6 kV breaker end.  

Why REF is now is used for HV side also in GT/SUT?

Description : Why REF is now is used for HV side also in GT/SUT?

Last Answer : The E/F setting of differential is poor.  

Which of the following equations is correct for Soderberg Criteria? a. (σ m / S ut ) + (σ a / S e ) = (1 / N f ) b. (σ m / S ut ) - (σ a / S e ) = (1 / N f ) c. (σ m / S yt ) + (σ a / S e ) = (1 / N f ) d. (σ m / S ut ) - (σ a / S e ) = (1 / N f )

Description : Which of the following equations is correct for Soderberg Criteria? a. (σ m / S ut ) + (σ a / S e ) = (1 / N f ) b. (σ m / S ut ) - (σ a / S e ) = (1 / N f ) c. (σ m / S yt ) + (σ a / S e ) = (1 / N f ) d. (σ m / S ut ) - (σ a / S e ) = (1 / N f )

Last Answer : c. (σ m / S yt ) + (σ a / S e ) = (1 / N f )

What are the protections for UT?

Description : What are the protections for UT?  

Last Answer : a) Differential protection b) LV restricted earthfault protection c) LV back up earthfault and over current protection d) Buchholz and high oil, winding temperature protection. 

Why main generator/UT is not provided with separate overfluxing protection?

Description : Why main generator/UT is not provided with separate overfluxing protection?

Last Answer : Since GT is provided with overfluxing protection, it is adequate to protect main generator / UT also. Main generator can withstand higher degree of overfluxing. If a generator CB is used, separate overfluxing protection is essential for main generator. 

During unit operation can we have one UT feeding both unit 6.6 kV loads?

Description : During unit operation can we have one UT feeding both unit 6.6 kV loads? 

Last Answer : No, logically prevented.  

Where fault level is more, whether in generator bus duct or UT bus duct? Why?

Description : Where fault level is more, whether in generator bus duct or UT bus duct? Why?

Last Answer : Fault level is more in UT bus duct. Because the fault currents fed by the both generator and GT adds up within UT bus duct in case there is a fault in UT bus duct. 

In which States/UT s e-Stamping is currently operational? A. Gujarat B. Karnataka C. Punjab D. All of the Above E. None of the Above

Description : In which States/UT s e-Stamping is currently operational? A. Gujarat B. Karnataka C. Punjab D. All of the Above E. None of the Above

Last Answer : D. All of the Above Explanation: e-Stamping is currently operational in the States/UT s of Gujarat, Karnataka, NCT Delhi, Assam, Tamil Nadu, Rajasthan, Himachal Pradesh, Uttarakhand, UT of ... Daman & Diu, Puducherry, Uttar Pradesh, Chhattisgarh, Jharkhand, Jammu & Kashmir, Punjab and Chandigarh.

Good hiking/camping spots in UT and CO?

Description : Good hiking/camping spots in UT and CO?

Last Answer : Gotta hit Bryce or Zion in Utah for sure! Both are spectacular. Look into reservations for camping online first, you may need to reserve a night now with the summer tourist hub kicking into high gear. Colorado I am less sure of, traveled through but didn’t camp anywhere.

Nightlife in Mesquite (NV) and St. George (UT)?

Description : Nightlife in Mesquite (NV) and St. George (UT)?

Last Answer : Remember Utah is a semi-dry state for alcohol, so if partying is part of the equation…. you have to go through a little extra to get to a bar. Mesquite has over five or six casinos/resorts. I’ve eaten at Virgin River in Mesquite.

Should I go to grad school at UC Irvine or UT Austin?

Description : Should I go to grad school at UC Irvine or UT Austin?

Last Answer : I think that would depend entirely on each school’s program.

I'm ut mobile and I have to recharge 100 MB of data once a month, but they can't run, please advise

Description : I'm ut mobile and I have to recharge 100 MB of data once a month, but they can't run, please advise

Last Answer : Need Answer

What is the mystery greene discusses and why does he say ut is something we should all care about?

Description : What is the mystery greene discusses and why does he say ut is something we should all care about?

Last Answer : Feel Free to Answer

Moab, UT?

Description : Moab, UT?

Last Answer : Moab, UT is a great site to visit. Until the 1950's Moab did nothave much to offer. Charlie Steen discovered uranium there and thetown has grown very quickly since that time. In Moab, UT there ... using whitewater rafting or a person can rent awhitewater raft and take their own tour.Moab, UT is n

How do I go about finding a caregiver for my elderly mother in Provo, UT?

Description : How do I go about finding a caregiver for my elderly mother in Provo, UT?

Last Answer : First, check in the local community for recommendations. Even if you live far away, call your mother's pastor or someone else that she knows in the community and ask for recommendations. If ... servicemagic has licensed, bonded, insured and rated caregivers listed for provo and the service is free.

Is there a tae kwon do class offered in Salt Lake City, UT?

Description : Is there a tae kwon do class offered in Salt Lake City, UT?

Last Answer : Yes. One in particular, is Master Kwon World Class, located at 3909 Highland Drive. Their phone number is (801) 272-5444, if you would like more information.

The Union Government on 22 May 2016 appointed whom as the new Lieutenant Governor of the Union Territory (UT) of Pondicherry? (1) Kiran Bedi (2) Kalyan Singh (3) Ram Naik (4) Mukul Sangma

Description : The Union Government on 22 May 2016 appointed whom as the new Lieutenant Governor of the Union Territory (UT) of Pondicherry? (1) Kiran Bedi (2) Kalyan Singh (3) Ram Naik (4) Mukul Sangma

Last Answer : (1) Kiran Bedi Explanation: BJP leader and former IPS officer Kiran Bedi was, in May 2016, appointed Lieutenant Governor of Puducherry. The post had been lying vacant after the Narendra Modi ... The Union Territory was under the additional charge of Lt. Governor of Andaman and Nicobar Islands.

Which amongst the following States/UT has not identified tribal community? (1) Chhattisgarh (2) Haryana (3) Maharashtra (4) Karnataka

Description : Which amongst the following States/UT has not identified tribal community? (1) Chhattisgarh (2) Haryana (3) Maharashtra (4) Karnataka

Last Answer : (2) Haryana Explanation: There are 84 million Scheduled Tribe persons in India as counted in the Census of 2001. Of them, about one third are in the Central Indian region comprising ... in the northern region of Jammu and Kashmir and the adjoining districts of Himachal Pradesh and Uttarakhand.

Cultivation of Heeng (Asafoetida) has been started in which state/ UT? a) Sikkim b) Jammu & Kashmir c) Himachal Pradesh d) Uttarakhand

Description : Cultivation of Heeng (Asafoetida) has been started in which state/ UT? a) Sikkim b) Jammu & Kashmir c) Himachal Pradesh d) Uttarakhand

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Botanical Words Alphabetical List - UT

Description : Botanical Words Alphabetical List - UT

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What is considered to be the oldest lake in North America? w) Mono Lake, CA x) Lake Superior, MI y) The Great Salt Lake, UT z) Crater Lake, OR

Description : What is considered to be the oldest lake in North America? w) Mono Lake, CA x) Lake Superior, MI y) The Great Salt Lake, UT z) Crater Lake, OR

Last Answer : ANSWER: W -- MONO LAKE, CA

Explain process of transmission ultrasonic testing and pulse echo UT testing.

Description : Explain process of transmission ultrasonic testing and pulse echo UT testing.

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Which of the device is employed in substation to limit the short circuit current in the power system: a) Shunt condenser b) Reactor c) Series capacitor d) Shunt capacitor

Description : Which of the device is employed in substation to limit the short circuit current in the power system: a) Shunt condenser b) Reactor c) Series capacitor d) Shunt capacitor

Last Answer : Ans: B

To limit the current flow through a DC voltmeter to as low a value as possible, the moving coil circuit is provided with a/an _____________. A. high series resistance B. high parallel resistance C. series inductor D. external shunt

Description : To limit the current flow through a DC voltmeter to as low a value as possible, the moving coil circuit is provided with a/an _____________. A. high series resistance B. high parallel resistance C. series inductor D. external shunt

Last Answer : Answer: A

The purpose of resistor bank 'R1-R5' in the winch circuit shown in the illustration is to ______________. EL-0102 A. limit armature current in lower and 'series field' current in hoist to obtain required speeds B. divert shunt field current for speed control in both directions of operation C. limit armature current in hoist and 'series field' current in lower to obtain required speeds D. regulate the strength of the brake solenoid 'B1-B2' in both directions of operation

Description : The purpose of resistor bank 'R1-R5' in the winch circuit shown in the illustration is to ______________. EL-0102 A. limit armature current in lower and 'series field' current in hoist to ... required speeds D. regulate the strength of the brake solenoid 'B1-B2' in both directions of operation

Last Answer : Answer: C

The purpose of 'R6' in the winch circuit shown in the illustration is to _______________. EL-0102 A. maintain dry conditions within the winch brake box B. keep the series field current at a low value during 'fourth and fifth point lowering' C. act as the armature dynamic braking load to assist the winch in stopping D. limit the armature current during lowering operation with heavy loads

Description : The purpose of 'R6' in the winch circuit shown in the illustration is to _______________. EL-0102 A. maintain dry conditions within the winch brake box B. keep the series field current at ... to assist the winch in stopping D. limit the armature current during lowering operation with heavy loads

Last Answer : Answer: C

The purpose of the 'heater resistors' for the winch circuit shown in the illustration is to _______________. EL-0102 A. limit the current in the heater circuit B. dispel moisture in the 'master switch' housing & control panel C. keep the winch brake housing below the dew point D. maintain winch motor operating temperature

Description : The purpose of the 'heater resistors' for the winch circuit shown in the illustration is to _______________. EL-0102 A. limit the current in the heater circuit B. dispel moisture in the ' ... panel C. keep the winch brake housing below the dew point D. maintain winch motor operating temperature

Last Answer : Answer: B

What is the function of the interpoles installed in DC motors? A. To provide greater torque by strengthening the main field. B. To provide sparkless commutation without having to shift the brushes. C. To limit the production of counter-electromotive force. D. To limit the starting surge current.

Description : What is the function of the interpoles installed in DC motors? A. To provide greater torque by strengthening the main field. B. To provide sparkless commutation without having to shift the brushes. C. To limit the production of counter-electromotive force. D. To limit the starting surge current.

Last Answer : Answer: B

The main purpose of the auxiliary winding on a split-phase, single-phase motor is to _____________. A. limit the starting voltage B. increase the starting current C. start the motor D. keep the motor running in the event the main winding should fail

Description : The main purpose of the auxiliary winding on a split-phase, single-phase motor is to _____________. A. limit the starting voltage B. increase the starting current C. start the motor D. keep the motor running in the event the main winding should fail

Last Answer : Answer: C

In the illustrated 450 VAC system, what should be provided between the bus and the device labeled 'F'? EL-0003 A. a potential transformer B. a current transformer C. an emergency disconnect device D. an audible alarm and indicating light

Description : In the illustrated 450 VAC system, what should be provided between the bus and the device labeled 'F'? EL-0003 A. a potential transformer B. a current transformer C. an emergency disconnect device D. an audible alarm and indicating light

Last Answer : Answer: A

Which device will stop the motor shown in the illustration in case of a short-circuit (high current) motor overload? EL-0080 A. 'F' B. 'G' C. 'H' D. 'I'

Description : Which device will stop the motor shown in the illustration in case of a short-circuit (high current) motor overload? EL-0080 A. 'F' B. 'G' C. 'H' D. 'I'

Last Answer : Answer: A

For V/F control, when frequency is increased in transformer a) Core loss component current increases, Magnetizing component current decreases b) Core loss component current increases, Magnetizing component current increases c) Core loss component current decreases, Magnetizing component current decreases d) Core loss component current decreases, Magnetizing component current increases

Description : For V/F control, when frequency is increased in transformer a) Core loss component current increases, Magnetizing component current decreases b) Core loss component current increases, ... component current decreases d) Core loss component current decreases, Magnetizing component current increases

Last Answer : Ans: Core loss component current decreases, Magnetizing component current decreases

If f:X->Y is continuous and x is a limit point of subset A of X, is f(x) a limit point of f(A)?

Description : If f:X->Y is continuous and x is a limit point of subset A of X, is f(x) a limit point of f(A)?

Last Answer : And here’s me, thinking i was the only one who heard that rumour…

In finding `lim_(x rarr a) f(x)`, we replace x by `(1)/(n)`, then the limit becomes _____.

Description : In finding `lim_(x rarr a) f(x)`, we replace x by `(1)/(n)`, then the limit becomes _____.

Last Answer : In finding `lim_(x rarr a) f(x)`, we replace x by `(1)/(n)`, then the limit becomes _____.

Mark the correct option a) There is no maximum limit of deposit in TD accounts of any type b) No subsequent withdrawal allowed in TD accounts before date of maturity c) The investment under 5 years TD qualifies for the benefit of Section 80C f the income tax Act 1961 from 01-04-2007 d) All the above

Description : Mark the correct option a) There is no maximum limit of deposit in TD accounts of any type b) No subsequent withdrawal allowed in TD accounts before date of maturity c) The investment under 5 years TD ... the benefit of Section 80C f the income tax Act 1961 from 01-04-2007 d) All the above

Last Answer : d) All the above

As shown in the illustration, the symbol is used in electrical drawings to designate a ____________. EL-0026 A. limit switch with one set of normally open contacts B. maintaining type push button with an electrical interlock C. sustaining type push button with a mechanical interlock D. normally closed contact held open mechanically by an interlock

Description : As shown in the illustration, the symbol is used in electrical drawings to designate a ____________. EL-0026 A. limit switch with one set of normally open contacts B. maintaining type ... type push button with a mechanical interlock D. normally closed contact held open mechanically by an interlock

Last Answer : Answer: C

The load sharing characteristics of two diesel alternators operating in parallel are directly related to the setting of their governors' ____________. A. load limit B. idle speed C. speed limit D. speed droop

Description : The load sharing characteristics of two diesel alternators operating in parallel are directly related to the setting of their governors' ____________. A. load limit B. idle speed C. speed limit D. speed droop

Last Answer : Answer: D

The purpose of a 'slew rate controller' in a circuit such as shown in the illustration is to ______________. EL-0096 A. limit the rate of change of a signal B. introduce a 'live zero' factor into the circuit C. shape the linear input into a non-linear output D. reduce air pressure to a value required by a combination circuit

Description : The purpose of a 'slew rate controller' in a circuit such as shown in the illustration is to ______________. EL-0096 A. limit the rate of change of a signal B. introduce a 'live zero' ... linear input into a non-linear output D. reduce air pressure to a value required by a combination circuit

Last Answer : Answer: A

One function of the movable cams in a drum-type motor controller is to _____________. A. regulate the speed of the motor B. maintain resistance contacts in clean condition C. insulate the operating handle D. limit the amount of load put on the motor

Description : One function of the movable cams in a drum-type motor controller is to _____________. A. regulate the speed of the motor B. maintain resistance contacts in clean condition C. insulate the operating handle D. limit the amount of load put on the motor

Last Answer : Answer: A

On an engine throttle control system, the auxiliary control circuits are provided with devices to prevent excessive overtravel of the pilot valve by the synchronous motor. These devices are called _________________. A. overlap sensors B. limit switches C. overtravel relays D. proximity switches

Description : On an engine throttle control system, the auxiliary control circuits are provided with devices to prevent excessive overtravel of the pilot valve by the synchronous motor. These devices are called _________________. A. overlap sensors B. limit switches C. overtravel relays D. proximity switches

Last Answer : Answer: B