What are the built in protections for transformers?

What are the built in protections for transformers?
by

1 Answer

Answer :

a) Buchholz relay

b) Explosion vent or relief valve

c) Gas operated relay for on load tap changers. 


by

Related questions

Why all 415V transformers are chosen Dyn 11? What are the protections provided for the 415V transformers?

Description : Why all 415V transformers are chosen Dyn 11? What are the protections provided for the 415V transformers?

Last Answer : a) To facilitate interchange. b) To have momentary parallel during changeover. Protections a) Door interlock to trip HT and LT breakers. b) LT breaker can on only after HT breaker is in on position. c) ... and restricted E/F (51N + 64). f) Winding temp high trip (140°C trip and 130°C alarm) 

What are the in-built protections provided in MCC cell?

Description : What are the in-built protections provided in MCC cell? 

Last Answer : Fuses for short circuit protection. OLR for over load and single phasing protection. Electrical and Mechanical interlock in valve cell against short circuit. 

What are the built in protections provided in 415 V breaker?

Description : What are the built in protections provided in 415 V breaker?  

Last Answer : a. DINF (making current magnetic release) This consists of a laminated magnetic circuit. This is placed under the lower current terminal pole. This is provided for all the three poles. It has a core that rotates ... by a lever. It is placed in front of the breaker. Setting range is 60% to 100%.  

What are the different Generator Protections employed in Thermal Power Plants?

Description : What are the different Generator Protections employed in Thermal Power Plants?

Last Answer : Answer: Faults in the windings, Over load protection, Over heating of windings or bearings, Over speed protection, Loss of Excitation protection, Motoring operation protection, Inadvertent ... , out of step operation protection, sub-synchronous oscillations protection and earth fault protection

What are the different Generator Protections employed in Thermal Power Plants?

Description : What are the different Generator Protections employed in Thermal Power Plants?

Last Answer : Faults in the windings, Over load protection, Over heating of windings or bearings, Over speed protection, Loss of Excitation protection, Motoring operation protection, Inadvertent energisation ... , out of step operation protection, sub-synchronous oscillations protection and earth fault protection

What are the protections provided for DG?

Description : What are the protections provided for DG?

Last Answer : 1. Differential protection (87). 2. Over speed of engine. 3. Reverse power protection (in LOCA condition time delay). 4. Low lubricating oil pressure. 5. Cooling water temperature high. 6. 6 ... 8. Emergency stops push button. In LOCA condition 4 - 8 protections are not permitted to operate. 

What are the protections used in 415 V Class II side?

Description : What are the protections used in 415 V Class II side?

Last Answer : LV to UPS 1. CTZM 2. 50 (instantaneous over current) 3. short circuit UPS to PMCC S & T 1. 51 RYB (inverse over current) 2. 27 (under voltage) 3. 51N (earth fault) From Class III to Class II tie CTZM at Class III and 51, 51N at Class II. 

What are the protections used in Class III & Class IV 415 V LV side?

Description : What are the protections used in Class III & Class IV 415 V LV side?  

Last Answer : Class III 415 V LV side 1. 51 (inverse over current) 2. 50 (instantaneous over current) 3. 27 (under voltage) 4. 51N (earth fault) 5. 64 (REF)  Class IV 415 V LV side 1. 51 RYB (inverse over current) 2. 51N (earth fault) 

What are the protections provided in charger?

Description : What are the protections provided in charger?  

Last Answer : 1. Over load (49). 2. Over voltage (59). 3. Short-circuit (3250 Amps). 4. Phase sequence and phase fail. 5. di/dt and dv/dt protection. 

What are the protections adopted in UPS or PMCC supply?

Description : What are the protections adopted in UPS or PMCC supply?

Last Answer : LV (incomer) or UPS input CTZM, Over current, Short circuit protections PMCC S or T input or UPS output Under voltage (27), 51RYB, 51N protections. 

What are the protections are there for lines?

Description : What are the protections are there for lines?  

Last Answer : Directional earthfault protection Directional over current protection Local breaker back up protection Pole discrepancy Main protection (distance protection)

What are the protections are there for BUSBAR?

Description : What are the protections are there for BUSBAR?

Last Answer : Instantaneous over current protection Bus bar differential protection Local breaker back up protection 

What are the protections provided in PMCC circuit breakers?

Description : What are the protections provided in PMCC circuit breakers?

Last Answer : 1. IDMT O/C (CDG 34). 2. IDMT E/F (CDG 11).  3. Under voltage (40% of 110V). 

What are the protections provided for motor feeder?

Description : What are the protections provided for motor feeder?  

Last Answer : Ith - Thermal over load I2S - Unbalance load I0S - Earth fault protection I1t - Stalling protection I1Inst. - Short circuit protection 

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. 

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. 

What are the protections for GENERATOR TRANSFORMER?

Description : What are the protections for GENERATOR TRANSFORMER?  

Last Answer : a) Differential protection b) Restricted earthfault protection c) Backup earthfault protection d) GT phase back up protection e) Overfluxing protection f) Oil surge (gas) protection g) High winding temperature and oil temperature protection. 

What are the working principles of generator main protections?

Description : What are the working principles of generator main protections?

Last Answer : GENERATOR START UP PROTECTIONS SUPPLEMENTARY PROTECTION OF GENERATOR The generator is normally expected to run rated speed before excitation power is applied by closing the field breaker. ... position to ensure that the protection is inoperable when the machine is connected to grid.  

What are the protections provided for 220 kV lines and bus bars?

Description : What are the protections provided for 220 kV lines and bus bars? 

Last Answer : a. Bus bar differential protection. b. Distance protection. c. Over current protection. d. Earth fault protection. 

Why are children considered deserving of protections that other weak or powerless individuals do not get?

Description : Why are children considered deserving of protections that other weak or powerless individuals do not get?

Last Answer : We do have protections in place. Every state has an Adult Protective Services division and that people are allowed to file bankruptcy rather than be held totally responsible for their debts is a form of protecting ... 't we can only protect them so far and so much and then they are on their own.

What store sells laptop protections?

Description : What store sells laptop protections?

Last Answer : Best Buy would have laptop protectors. And yes it would be a good investment to buy one for your laptop. It will protect your laptop from getting scratched or dinged from being dropped.

How are circuits protections devices connected to the circuit they are intended to protect and why are they connected in this way?

Description : How are circuits protections devices connected to the circuit they are intended to protect and why are they connected in this way?

Last Answer : In series, so total current will be stopped when the device opens.

State the types of protections provided by MCB.

Description : State the types of protections provided by MCB. 

Last Answer : The types of protections provided by MCB: 1. MCB provides short circuit protection. 2. MCB provides overload protection

Two transformers of identical voltages but different capacities are operated in parallel, for satisfactory load sharing: a) Impedances should be equal b) Per unit impedance must be equal c) per unit impedance and X/R ratio must be equal d) Impedance and X/R ratio must be equal

Description : Two transformers of identical voltages but different capacities are operated in parallel, for satisfactory load sharing: a) Impedances should be equal b) Per unit impedance must be equal c) per unit impedance and X/R ratio must be equal d) Impedance and X/R ratio must be equal

Last Answer : Ans: C

Equalization of the power factors of two alternators operating in parallel is accomplished _____________. A. manually, by adjusting the governor controls B. automatically, by automatic voltage regulators C. manually, adjusting the output of current transformers D. automatically, by the designed action of the governors

Description : Equalization of the power factors of two alternators operating in parallel is accomplished _____________. A. manually, by adjusting the governor controls B. automatically, by automatic voltage regulators ... the output of current transformers D. automatically, by the designed action of the governors

Last Answer : Answer: B

Routine maintenance of dry-type transformers should include ______________. A. preventing the entrance of water from broken pipe lines steam lines B. keeping protective surfaces and insulating bushings free of dirt and conductive debris C. periodic testing of insulation resistance with a megger D. all of the above

Description : Routine maintenance of dry-type transformers should include ______________. A. preventing the entrance of water from broken pipe lines steam lines B. keeping protective surfaces and insulating bushings free of ... debris C. periodic testing of insulation resistance with a megger D. all of the above

Last Answer : Answer: D

In the illustrated electronic governor, the circuit card connected to the potential and current transformers is for ________. EL-0046 A. increasing the signal strength to the governor to maintain constant engine speed with increased load B. send a kilowatt signal to the metering circuit C. shutting down the prime mover in the event of reverse power to protect from motorization D. conditioning the load through the use of a magnetic amplifier current transformer

Description : In the illustrated electronic governor, the circuit card connected to the potential and current transformers is for ________. EL-0046 A. increasing the signal strength to the governor to ... from motorization D. conditioning the load through the use of a magnetic amplifier current transformer

Last Answer : Answer: A

If all three ground-detection lamps continue to burn at equal intensity after the test button is depressed and released, which of the listed conditions is indicated? A. No grounds exist B. All three phases are grounded C. The test switch is faulty D. The current transformers are shorted out

Description : If all three ground-detection lamps continue to burn at equal intensity after the test button is depressed and released, which of the listed conditions is indicated? A. No grounds exist B. All three phases are grounded C. The test switch is faulty D. The current transformers are shorted out

Last Answer : Answer: A

Which of the listed transformer uses a single winding to produce voltage transformation? A. Stepup transformers B. Stepdown transformers C. Autotransformers D. Isolation transformers

Description : Which of the listed transformer uses a single winding to produce voltage transformation? A. Stepup transformers B. Stepdown transformers C. Autotransformers D. Isolation transformers

Last Answer : Answer: C

Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency controllers D. permit higher voltage for electric motor operation and low voltage for lighting circuits

Description : Transformers are used onboard ships with AC generators to _____________. A. change frequency B. increase power output to modulating frequency controllers C. decrease power output to modulating frequency ... D. permit higher voltage for electric motor operation and low voltage for lighting circuits

Last Answer : Answer: D

On a switchboard, if all three ground detection lamps remain burning at half intensity when the test button is depressed, which of the listed conditions is indicated? A. No grounds exist. B. All three phases are grounded. C. The test switch is grounded. D. The current transformers are shorted.

Description : On a switchboard, if all three ground detection lamps remain burning at half intensity when the test button is depressed, which of the listed conditions is indicated? A. No grounds exist. B. All three phases are grounded. C. The test switch is grounded. D. The current transformers are shorted.

Last Answer : Answer: A

Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding temperature with an accurate mercury thermometer C. periodic cleaning of the winding insulation with an approved solvent D. making sure that the units are close to bulkheads or corners to protect them from damage

Description : Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding ... . making sure that the units are close to bulkheads or corners to protect them from damage

Last Answer : Answer: A

Power transformers are rated in _____________. A. kilowatts B. ampere-turns C. kilowatt-volts D. kilovolt-amperes

Description : Power transformers are rated in _____________. A. kilowatts B. ampere-turns C. kilowatt-volts D. kilovolt-amperes

Last Answer : Answer: D

What is the significance of vector grouping in Power Transformers?

Description : What is the significance of vector grouping in Power Transformers?

Last Answer : Every power transformer has a vector group listed by its manufacturer. Fundamentally it tells you the information about how the windings are connected (delta or wye) and the phase difference between the ... Delta primary, Wye Secondary and the current is at 11 o clock referred to the voltage.

What is the significance of vector grouping in Power Transformers?

Description : What is the significance of vector grouping in Power Transformers?

Last Answer : A: Every power transformer carries a vector group listed by its manufacturer. Fundamentally it tells you the information about how the windings are connected (delta or wye) and the phase difference between ... Delta primary, Wye Secondary and the current is at 11 o clock referred to the voltage.

Why Silica gel is used in transformers?

Description : Why Silica gel is used in transformers?

Last Answer : Silica Gel is used to remove the moisture in the air entering in to the transformer. During the breathing of the transformer air enters in to the transformer. This air makes contact with the hot ... Silica gel crystals will be in blue color initially and after absorbing moisture it turns to pink.

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 is the significance of vector grouping in Power Transformers?

Description : What is the significance of vector grouping in Power Transformers?

Last Answer : Answer:Every power transformer has a vector group listed by its manufacturer. Fundamentally it tells you the information about how the windings are connected (delta or wye) and the phace difference betweent ... Delta primary, Wye Secondry and the current is at 11 o clock reffered to the voltage.

How is magnetic leakage reduced to a minimum in commercial transformers?

Description : How is magnetic leakage reduced to a minimum in commercial transformers?

Last Answer : By interleaving the primary and secondary windings.

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

Can Transformers be Reconnected as Autotransformers to Increase Their KVA Rating?

Description : Can Transformers be Reconnected as Autotransformers to Increase Their KVA Rating?

Last Answer : ANSWER: Several of standard single phase transformers can be connected as autotransformers. The KVA capacity will be greatly increased when used as an Autotransformer, in comparison to the ... This voltage is normally used for operating fluorescent lamps or similar devices requiring 277 volts

What is BIL and How Does it Apply to our Transformers ?

Description : What is BIL and How Does it Apply to our Transformers ?

Last Answer : ANSWER: BIL is an abbreviation for Basic Impulse Level. Impulse tests are dielectric tests that consist of the applica¬tion of a high frequency steep wave front voltage between windings ... breakdowns when his system is properly protected with lightning arrestors or similar surge protection devices.

What is Meant by "Impedance" in Transformers?

Description : What is Meant by "Impedance" in Transformers?

Last Answer : ANSWER: Impedance is the current limiting characteristic of a transformer and is expressed in percentage.

Can 60 Hz Transformers be Used at Higher Frequencies?

Description : Can 60 Hz Transformers be Used at Higher Frequencies?

Last Answer : A: Transformers can be used at fre¬quencies above 50 Hz up through 400 Hz with no limitations provided nameplate voltages are not exceeded. However, 50 Hz transformers will have less voltage ... Where better regulation and smaller physical size are required, contact us for special 400 Hz designs.

What are the Conditions for parallel operation of transformers?

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

Last Answer : A. a) Same voltage ratio of transformer: If two transformers of different voltage ratio, are connected in parallel with same primary supply voltage, there will be a difference in secondary voltages. If ... not in same phase sequence, during the cycle, each pair of phases will be short circuited.

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.

Can the transformers be used at higher frequencies than rated frequency?

Description : Can the transformers be used at higher frequencies than rated frequency?

Last Answer : A. Yes. Transformers can be used at higher frequencies than rated frequency. However as the frequency increases voltage regulation decreases.

What is meant by “impedance” in transformers? Why is it important?

Description : What is meant by “impedance” in transformers? Why is it important?

Last Answer : A. Impedance is the current limiting characteristic of a transformer and is expressed in percentage. It is used for determining the interrupting capacity of a circuit breaker or fuse employed to protect the primary of a transformer

Can Single Phase Transformers be used for Three Phase applications?

Description : Can Single Phase Transformers be used for Three Phase applications?

Last Answer : A. Yes. Three phase transformers are sometimes not readily available whereas single phase transformers can generally be found in stock. Three single phase transformers can be used in delta connected primary and ... K VA single phase transformers can be used to accommodate a 30 KVA three phase load.

Can Transformers develop Three Phase power from a Single Phase source?

Description : Can Transformers develop Three Phase power from a Single Phase source?

Last Answer : A. NO. Phase converters or phase shifting devices such as reactors and capacitors are required to convert single phase power to three phase.