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

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

Answer :

No, due to switchgear limitation.  
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Related questions

During unit operation, can we parallel 2 SUT?

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

Last Answer : No, due to switchgear limitation. 

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 

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

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

Last Answer : 400a limited by 10 ohms resistor.  

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.

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.  

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) 

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.  

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. 

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. 

Can we trip GFB from control room during unit operation?

Description : Can we trip GFB from control room during unit operation?  

Last Answer : No only if generator breaker is off.  

A vessel is equipped with two ship's service generators. Generator #1 is rated at 900 kw and generator #2 is rated at 600 kw. During parallel operation, with a hotel load of 1,000 kw, what should be the kw load on generator #2? A. 100 kw B. 400 kw C. 500 kw D. 600 kw

Description : A vessel is equipped with two ship's service generators. Generator #1 is rated at 900 kw and generator #2 is rated at 600 kw. During parallel operation, with a hotel load of 1,000 kw, what should be the kw load on generator #2? A. 100 kw B. 400 kw C. 500 kw D. 600 kw

Last Answer : Answer: B

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

Last Answer : c) Himachal Pradesh

Caution must be exercised during the charging of lead-acid storage batteries as _____________. A. the acid will become weaker B. hydrogen gas is being continuously liberated C. both plates are changing chemically to lead sulfate D. lead peroxide in the negative plate is poisonous

Description : Caution must be exercised during the charging of lead-acid storage batteries as _____________. A. the acid will become weaker B. hydrogen gas is being continuously liberated C. both plates are changing chemically to lead sulfate D. lead peroxide in the negative plate is poisonous

Last Answer : Answer: B

Drives on a road suitable for parallel traffic where the road markings separating the traffic lanes are not visible. Where can you drive continuously if the traffic on the road is insignificant? (Cross Test)

Description : In the rightmost traffic lane. In a residential area, outside any residential area in the rightmost traffic lane. In any traffic lane.   

Last Answer : In the far right lane. Explanation: This is clear from the right-of-way obligation in this case. This question can be varied in many ways, depending on whether there are road markings or not, whether ... test book! (cross test / Driving on the road / Driving on a road suitable for parallel traffic)

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

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Coast Guard Regulations (46 CFR) require that each alternating current generator arranged for parallel operation shall be provided with _____________. A. more than one means of excitation B. individual circuit fuses C. a high back-pressure trip D. a reverse-power trip

Description : Coast Guard Regulations (46 CFR) require that each alternating current generator arranged for parallel operation shall be provided with _____________. A. more than one means of excitation B. individual circuit fuses C. a high back-pressure trip D. a reverse-power trip

Last Answer : Answer: D

Which of the following statements is true concerning the operation of two alternators in parallel? A. The cycles per second of each alternator are the same. B. Both alternator governors must be set with the same amount of speed droop. C. The number of field poles must be the same on each alternator. D. The load must always be divided equally between alternators.

Description : Which of the following statements is true concerning the operation of two alternators in parallel? A. The cycles per second of each alternator are the same. B. Both alternator governors must be set ... be the same on each alternator. D. The load must always be divided equally between alternators.

Last Answer : Answer: A

Which of the following should be the FIRST step in removing a generator from parallel operation? A. Trip the generator off the switchboard. B. Turn off all electrical equipment. C. Remove the load from the 'off going' generator. D. Increase the cycles of the generator staying on the line.

Description : Which of the following should be the FIRST step in removing a generator from parallel operation? A. Trip the generator off the switchboard. B. Turn off all electrical equipment. C. Remove the load from the 'off going' generator. D. Increase the cycles of the generator staying on the line.

Last Answer : Answer: C

In the illustration, the contacts between terminals 26 and 27 should be closed when _________. EL-0046 A. using one generator in isochronous mode only B. using two or more generators in parallel only C. the prime mover speed is to remain constant through varying loads in parallel or single operation D. the circuit breaker is closed for that generator

Description : In the illustration, the contacts between terminals 26 and 27 should be closed when _________. EL-0046 A. using one generator in isochronous mode only B. using two or more generators in ... through varying loads in parallel or single operation D. the circuit breaker is closed for that generator

Last Answer : Answer: C

What are the conditions for parallel operation of two transformers ?

Description : What are the conditions for parallel operation of two transformers ?

Last Answer : Transformers which are to be operated parallel should have to satisfy the following conditions: Polarities of both the transformers should be same else lead to short circuit Voltage rating of ... Phase displacement of transformers should be same Phase sequence of two transformers should be same

What are the conditions for parallel operation of two transformers ?

Description : What are the conditions for parallel operation of two transformers ?

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What are the Conditions for parallel operation of transformers?

Description : What are the Conditions for parallel operation of transformers?

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What are the advantages of parallel operation of transformers?

Description : What are the advantages of parallel operation of transformers?

Last Answer : A. 1) To maximize electrical power system efficiency: Generally electrical power transformer gives the maximum efficiency at full load. If we run numbers of transformers in parallel, we can switch ... running in parallel can be removed from system to balance the capital investment and its return.

What Are The Conditions To Be Satisfied For Parallel Operation Of Dc Generators?

Description : What Are The Conditions To Be Satisfied For Parallel Operation Of Dc Generators?

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What steps are to be taken before disconnecting one Alternator from parallel operation?

Description : What steps are to be taken before disconnecting one Alternator from parallel operation?

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Description : What is need of parallel operation of alternators?

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Description : What are the conditions for parallel operation of transformer?

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What is the need for parallel operation of transformer?

Description : What is the need for parallel operation of transformer?

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A lead-acid battery can deliver 20 amperes continuously for 10 hours with an ampere-hour rating of ____________. A. 20 B. 40 C. 200 D. 400

Description : A lead-acid battery can deliver 20 amperes continuously for 10 hours with an ampere-hour rating of ____________. A. 20 B. 40 C. 200 D. 400

Last Answer : Answer: C

When a battery is continuously exposed to low temperatures, the best procedure to keep it from freezing is to _________. A. remove the battery caps B. securely cover the battery C. keep the battery fully charged D. disconnect the battery

Description : When a battery is continuously exposed to low temperatures, the best procedure to keep it from freezing is to _________. A. remove the battery caps B. securely cover the battery C. keep the battery fully charged D. disconnect the battery

Last Answer : Answer: C

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Description : Which of the following procedures represents the best method to prevent the freezing of batteries continuously exposed to low temperatures? A. The battery caps should be removed. B. The battery cap ... in a fully charged condition. D. The battery should be disconnected from its charging source.

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The standard procedure for maintaining the charge in an emergency diesel starting battery is to trickle charge the battery _____________. A. continuously B. at least once each week C. whenever the charge falls to 75% of full charge D. whenever the electrolyte specific gravity falls to 1.250 or lower

Description : The standard procedure for maintaining the charge in an emergency diesel starting battery is to trickle charge the battery _____________. A. continuously B. at least once each week C. whenever the charge falls to 75% of full charge D. whenever the electrolyte specific gravity falls to 1.250 or lower

Last Answer : Answer: A

A motor controller contains three selector push buttons labeled 'start', 'jog', and 'stop'. When the 'jog' button is pushed, the motor _____________. A. will run continuously after the 'jog' button is released B. will run until the 'jog' button is released C. will not start until both the 'jog' and 'start' buttons are pushed D. will not stop unless the 'stop' button is pushed

Description : A motor controller contains three selector push buttons labeled 'start', 'jog', and 'stop'. When the 'jog' button is pushed, the motor _____________. A. will run continuously after the 'jog' button is ... 'jog' and 'start' buttons are pushed D. will not stop unless the 'stop' button is pushed

Last Answer : Answer: B

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

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.