What is the purpose of spring charging in 415 V breaker? 

1 Answer

Answer :

If the breaker is to be closed and tripped manually the closing time and tripping time would vary from person to person. Also it would not be very fast. So spring charging is provided. It gives uniform timings irrespective of the operator and its action is fast and closing and tripping time is very less. 

Related questions

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%.  

Description : Explain clearly the three positions in 415 V breaker. 

Last Answer : a. Service position: Power connections and control connections are available to the breaker. b. Test position: Power connections are cut off but control connections are available to the breaker and ... the breaker and in this positions both the control and power connections are not available. 

Description : What are the types of cables used in 6.6 kV and 415 V system voltages? 

Last Answer : In 6.6 kV system AC (unearthed) grade having stranded aluminium conductors cables are used. Their insulation's are as follows. 1. XLPE - Crossed linked polyethylene insulation. 2. FRLS PVC - Fire ... V grade copper or aluminium stranded cables are used. Their insulations are HR PVC and FS type. 

Description : What are the interlocks between 415 V and 6.6 kV switch gear? 

Last Answer : 6.6 kV Breaker closed cannot rack in or out. Service lever cannot move while breaker closed. Breaker cannot be closed in in-between position. 415 V Breaker door cannot be opened when breaker is ... . Breaker cannot be closed in in-between position. Breaker closed cannot be rack in or out. 

Description : What is the difference between lockout of 6.6 kV and 415 V CB’s?

Last Answer : Voltage levels. Manual / auto reset. Lockout relays of 415 V breakers are all Electro-magnetic type. There is no mechanical latch. But in 6.6 kV it is of mechanical latch type relays.

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. 

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) 

Description : Why resistance grounding preferred for less than 33 kV and more than 415 V?

Last Answer : a) To limit the earth fault current for equipment safety else, high short ckt forces dislocate in windings/bus bars etc, b) Over voltage due to arcing ground reduced c) Permits earth fault protection (not possible in ungrounded system)

Description : Where a thermal-acting breaker is required to be used in an area of unusually high, low, or constantly fluctuating temperatures, an ambient compensating element must be used. This element consists of ... arm B. conical spring on the contact arm C. second bimetal element D. second electromagnet

Last Answer : Answer: C

Description : A 100 kVA, 415 V(line), star-connected synchronous machine generates rated open circuit voltage of 415 V at a field current of 15 A. The short circuit armature current at a field current of 10 A is equal to the ... unit saturated synchronous reactance is  (A) 1.731 (B) 1.5 (C) 0.666 (D) 0.577

Last Answer : 0.6

Description : In the illustration, the purpose of part B is to _________. EL-0033 A. increase resistance in series with the contacts as they close to prevent arcing B. create a magnetic field in the steel ... event of an overload D. provide ventilation to the contact when the breaker is close to rated capacity

Last Answer : Answer: B

Description : The purpose of a main switchboard circuit breaker's reverse-power trip is to _____________. A. prevent main circuit overload B. protect the circuit breaker blowout coil C. prevent alternator motorization D. prevent low voltage tripout

Last Answer : Answer: C

Description : What is the purpose of compressed air in SF6 breaker?

Last Answer : This used for drive for opening and closing of the contacts. (Arc quenching is taken care by SF6 gas) 

Description : What is the purpose of header breaker in water circuit?

Last Answer : The header breaker ensures oil pressure greater than that of water pressure always. Therefore there is no leak of water into oil.  

Description : Purpose of Local breaker back-up relay; type -CTIG

Last Answer : To safe guard against the drastic consequences of failure to clear faults rapidly, many power supply authorities install 2 independent systems of protection for major transmission lines. There remains however the ... reset, which enables the time delay to be set closer to the breaker trip-time. 

Description : How serious is a triglyceride reading of 415 in a senior?

Last Answer : Wow! My understanding is that it should be under 200. That would seem to be off the charts, but I also understand that the result should be taken in context with other readings, such as total cholesterol, ... does raise a red flag and your s/o should check with a physician to have other tests run.

Description : What is 415 round to the nearest 100?

Last Answer : 400

Description : Highest test partnership by a pair in test cricket history is 415 runs. A. Jayasuriya and Mahnama (SL Vs India) B. Sangakara and Jayawardene (SL Vs SA) C. Neil McKenzie and Gram Smith (SA Vs Bangladesh) D. Trott and Broad (Eng Vs Pak)

Last Answer : ANSWER: C

Description : Highest test partnership by a pair in test cricket history is 415 runs. A. Jayasuriya and Mahnama (SL Vs India) B. Sangakara and Jayawardene (SL Vs SA) C. Neil McKenzie and Gram Smith (SA Vs Bangladesh) D. Trott and Broad (Eng Vs Pak)

Last Answer : ANSWER: C

Description : Highest test partnership by a pair in test cricket history is 415 runs. A. Jayasuriya and Mahnama (SL Vs India) B. Sangakara and Jayawardene (SL Vs SA) C. Neil McKenzie and Gram Smith (SA Vs Bangladesh) D. Trott and Broad (Eng Vs Pak)

Last Answer : ANSWER: C

Description : Highest test partnership by a pair in test cricket history is 415 runs. A. Jayasuriya and Mahnama (SL Vs India) B. Sangakara and Jayawardene (SL Vs SA) C. Neil McKenzie and Gram Smith (SA Vs Bangladesh) D. Trott and Broad (Eng Vs Pak)

Last Answer : ANSWER: C

Description : The compression in steel (fS) at failure for Fe - 415 grade steel using stress-strain curve shall be [ A ] 0.87 fy [ B ] 0.75 fy [ C ] 0.45 fy [ D ] 0.55 fy

Last Answer : [ B ] 0.75 fy

Description : According to IS: 456-2000 the ultimate moment of resistance of a slab for Fe - 415 HYSD bars is; [ A ] Mu = 0.138 fck bd2 [ B ] Mu = 0.145 fck bd2 [ C ] Mu = 0.152 fck bd2 [ D ] Mu = 0.165 fck bd2

Last Answer : [ A ] Mu = 0.138 fck bd2

Description : The Minimum percentage of secondary steel in slabs for Fe- 415 grade steel should be __________ of Gross cross-section area [ A ] 0.12% [ B ] 0.15% [ C ] 0.20% [ D ] 0.25%

Last Answer : [ A ] 0.12%

Description : For Fe- 415 steel and M20grade concrete, the balanced percentage of steel is [ A ] 0.65% [ B ] 0.75% [ C ] 0.86% [ D ] 0.96%

Last Answer : [ D ] 0.96%

Description : The Minimum amount of steel for Main reinforcement in slab should be (Fe 415- grade of steel) [ A ] 0.12 percent of gross cross sectional area [ B ] 0.15 percent of gross cross sectional area [ C ] 0.20 percent of gross cross sectional area [ D ] 0.25 percent of gross cross sectional area.

Last Answer : [ A ] 0.12 percent of gross cross sectional area

Description : As per IS: 1139, permissible stress in compression steel reinforcement for High Yield strength deformed bars is [ A ] 140 N/mm2 [ B ] 190 N/mm2 [ C ] 230 N/mm2 [ D ] 415 N/mm2

Last Answer : [ B ] 190 N/mm2

Description : As per IS:1139, the characteristic yield strength for cold twisted deformed bars is [ A ] 250 N/mm2 [ B ] 415 N/mm2 [ C ] 500 N/mm2 [ D ] 550 N/mm2

Last Answer : [ C ] 500 N/mm2

Description : As per IS:1139, the characteristic yield strength for hot rolled High yield strength deformed bars is [ A ] 250 N/mm2 [ B ] 415 N/mm2 [ C ] 500 N/mm2 [ D ] 550 N/mm2

Last Answer : [ B ] 415 N/mm2

Description : Brother A and B had some savings in the ratio 5:6. They decided to buy a gift for their sister, sharing the cost in the ratio 4:5. After they bought, A is left with three-fourth of his amount, while B is left with Rs.497. Then, the value of the gift is a) 215 b) 115 c) 315 d) 415 e) None of these

Last Answer : Answer: C Let the savings of A and B are 5x, 6x and the share cost of gift are 4y, 5y respectively. According to question, For A, 5x-4y=3/4×5x =>x=16y/5 For B, 6x-5y=497 =>6×16y/5-5y=497 =>y=35 Cost of gift=4y+5y=9×35 =315

Description : Which of the listed safety features should be provided in small rooms or lockers where batteries are stored? A. Installation of a fixed CO2 system. B. An exhaust duct is to be provided and led from within ... An exhaust duct is to be provided and led from the top of the locker to the open air.

Last Answer : Answer: D

Description : According to Coast Guard Regulations (46 CFR), which of the following systems must be arranged so as to be energized by the final emergency power source? A. at least one light in the ... operated watertight door system C. each charging panel for temporary emergency batteries D. all of the above

Last Answer : Answer: D

Description : Maintenance of alkaline batteries should include _________. A. checking the electrolyte weekly using a hydrometer B. replacing the electrolyte every 5 years C. trickle charging D. replacment when the volts per cell drops below 1.8 VDC

Last Answer : Answer: C

Description : Violent gassing developed by a lead-acid battery during charging indicates that the ____________. A. plate separators are grounded B. cell voltages are excessive C. specific gravity in insufficient D. charging rate is excessive

Last Answer : Answer: D

Description : If violent gassing occurs when a lead-acid storage battery is first placed on charge, the _____________. A. battery must be given an emergency charge B. charging rate is too low C. charging rate is too high D. specific gravity of the electrolyte solution is too low

Last Answer : Answer: C

Description : Which of the following problems is indicated if a lead-acid battery begins to gas violently when it is first placed on charge? A. Insufficient compartment ventilation is being provided. B. A short ... undergoing its normal charging rate. D. An excessive charging rate is being applied to the battery.

Last Answer : Answer: D

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.

Last Answer : Answer: C

Description : When a battery-charging panel is being used, the batteries will discharge if _____________. A. DC voltage is supplied B. the polarity is reversed C. the voltage fluctuates D. too little current is supplied

Last Answer : Answer: B

Description : Under normal conditions, storage batteries used for starting the emergency diesel generator are maintained in a charged state by which of the following methods? A. Trickle charging B. Fast charging C. Equalizing charge D. Reverse charging

Last Answer : Answer: A

Description : Proper storage battery maintenance includes ____________. A. keeping connections tight and casing surfaces clean B. making sure electrolyte level is below the separator plates C. insulating the terminals with naval jelly D. maintaining a high charging rate at all times

Last Answer : Answer: A

Description : A slow continual loss of electrolyte level from one cell of a storage battery could be due to _______________. A. a cracked casing B. too low a charging rate C. the specific gravity being higher than normal D. one filler cap installed too tightly

Last Answer : Answer: A

Description : When a lead-acid battery begins gassing freely while receiving a normal charge, the charging current should _____________. A. be increased B. remain unchanged C. be decreased D. shut off

Last Answer : Answer: C

Description : Which of the processes listed occurs during the charging of a lead-acid storage battery? A. Negative plates change to lead peroxide. B. Positive plates change to lead peroxide. C. Both plates change to lead peroxide. D. Both plates change to lead sulfate.

Last Answer : Answer: B

Description : The specific gravity of the electrolyte solution in a lead acid battery _____________. A. is not effected during charging B. remains the same during discharge C. would read close to 1.830 when discharged D. gives an indication of the state of charge of the battery

Last Answer : Answer: D

Description : Which of the following activities occurs during the charging process of a lead-acid storage battery? A. The specific gravity of the acid increases. B. Both plates change chemically to lead sulfate. C. The specific gravity of the acid decreases. D. Hydrogen gas is absorbed.

Last Answer : Answer: A

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

Description : When a lead-acid battery begins gassing freely while receiving a normal charge, the charging current should be _____________. A. increased B. shut off C. decreased D. unchanged

Last Answer : Answer: C

Description : Violent gassing from a lead-acid battery while it is being charged, indicates that the _____________. A. plate separators are grounded B. battery compartment ventilation is inadequate C. electrolyte specific gravity is too low D. charging rate is too high

Last Answer : Answer: D

Description : Which of the following conditions indicates a short circuited capacitor when checking its condition with an ohmmeter? A. The capacitor shows charging, but the final resistance reading is appreciably less ... moves quickly to the low resistance side of the scale, then slowly recedes toward infinity.

Last Answer : Answer: B