What are the materials in contact with PHT system?

What are the materials in contact with PHT system?
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1 Answer

Answer :

Piping – carbon steel.

Pressure tubes – zircalloy-2

Fuel cladding – zircalloy-2

End shield – stainless steel. Etc. 
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Related questions

Why bi-directional flow is chosen for PHT system?

Description : Why bi-directional flow is chosen for PHT system?

Last Answer : Bi-directional flow is chosen for PHT system because, a. Uniform temperature gradient is facilitated so there will be no differential thermal expansion. b. It facilitates fuelling even when the ... , which facilitates uniform neutron flux and this intern gives rise to maximum fuel burns up. 

What are the main futures of PHT system?

Description : What are the main futures of PHT system?  

Last Answer : a. Impeller – To reduce the water flow. b. Self-injection Hx – Cools the water in case of leakage. c. Gland supply – Cools the seals. d. Primary and secondary seals – sealing the pump. e. Thrust bearing – To take the axial thrust. 

How coolant flow is maintained in the event of loss of power to the PHT system?

Description : How coolant flow is maintained in the event of loss of power to the PHT system?

Last Answer : When the PHT power fails, it takes two minutes for DG to come to full power. The circulation is maintained by flywheel, which increases the de-acceleration and maintains the flow for two minutes. If ... which more denser cold water comes down and less denser hot water goes up by convection method. 

What FCN was implemented to avoid reactor trip on 220V-DC failure of PHT and PPP breakers?

Description : What FCN was implemented to avoid reactor trip on 220V-DC failure of PHT and PPP breakers?

Last Answer : The breaker close position supervision relay VAA 21 is changed by VAJC type, contacts position do not change if 220V-DC is lost now.

What is the 2 stage stalling protection for PHT motor?

Description : What is the 2 stage stalling protection for PHT motor?

Last Answer : Because locked rotors withstand time of motor is less than starting time of motor under reduced voltage conditions. Stage 1 = 350% 6 sec for starting at rated voltage (Because starting time = 6 ... time under reduced voltage condition (Since starting current is less, stage 1 will not operate) 

Why differential protection for PHT motors?

Description : Why differential protection for PHT motors?

Last Answer : For more than 2500 kW motors it is required to provide differential protection. It is biased Relay against internal phase fault or earth fault very fast. Insensitive to starting current and stalling current. 

What happen to the rock that came in contact with the molten materials of the intruded dike?

Description : What happen to the rock that came in contact with the molten materials of the intruded dike?

Last Answer : Don’t know

Powdery materials can be guarded against caking tendency on storage by (A) Providing irregular grain size (B) Providing minimum percentage of voids (C) Having maximum possible points of contact (D) None of these

Description : Powdery materials can be guarded against caking tendency on storage by (A) Providing irregular grain size (B) Providing minimum percentage of voids (C) Having maximum possible points of contact (D) None of these

Last Answer : (D) None of these

Pick up wrong statement about friction force for dry surfaces. Friction force is (A) Proportional to normal load between the surfaces (B) Dependent on the materials of contact surface (C) Proportional to velocity of sliding (D) Independent of the area of contact surfaces

Description : Pick up wrong statement about friction force for dry surfaces. Friction force is  (A) Proportional to normal load between the surfaces  (B) Dependent on the materials of contact surface  (C) Proportional to velocity of sliding  (D) Independent of the area of contact surfaces 

Last Answer : (C) Proportional to velocity of sliding 

Electrical contact materials used in switches, brushes and relays must possess

Description : Electrical contact materials used in switches, brushes and relays must possess   (A) high thermal conductivity and high melting point  (B) Low thermal conductivity and low melting point   (C) High thermal conductivity and low melting point  (D) Low thermal conductivity and high melting point.

Last Answer : Electrical contact materials used in switches, brushes and relays must possess high thermal conductivity and high melting point 

Which of the following represents a characteristic of an ungrounded electrical distribution system? A. Accidental contact between one line and ground does not cause an outage. B. Double ground faults on different phases will not cause an outage. C. Ground detection systems are unnecessary. D. Accidental contact between one line and ground will always cause an outage.

Description : Which of the following represents a characteristic of an ungrounded electrical distribution system? A. Accidental contact between one line and ground does not cause an outage. B. Double ground faults on ... unnecessary. D. Accidental contact between one line and ground will always cause an outage.

Last Answer : Answer: A

Due to which of the following factors the brush wear rate is altered ? (a) Speed of the machine (b) Contact pressure (c) Surface conditions of brush and commutator (d) Excessive sparking (e) All of the above

Description : Due to which of the following factors the brush wear rate is altered ? (a) Speed of the machine (b) Contact pressure (c) Surface conditions of brush and commutator (d) Excessive sparking (e) All of the above

Last Answer : Ans: E

From the standpoint of safety, you should never allow salt water to enter a leadacid storage battery or come in contact with sulfuric acid because ______________. A. the resulting gas is extremely flammable B. the resulting gas is a respiratory irritant that can be fatal C. the primary constituent, sodium, reacts lethally with lead peroxide D. combining salt water with lead-acid creates an invisible gas resulting in severe corrosion

Description : From the standpoint of safety, you should never allow salt water to enter a leadacid storage battery or come in contact with sulfuric acid because ______________. A. the resulting gas is ... peroxide D. combining salt water with lead-acid creates an invisible gas resulting in severe corrosion

Last Answer : Answer: B

As shown in the illustration, once the "LV" relay is energized for operation, what contacts must remain closed to maintain the "LV" relay energized when the control lever is moved away from the "off" or "stop" position? A. "DBa" contact. B. Reset contacts. C. Upper set of "LVa" contacts. D. Lower set of "LVa" contacts.

Description : As shown in the illustration, once the "LV" relay is energized for operation, what contacts must remain closed to maintain the "LV" relay energized when the control lever is moved away from the "off" or "stop" ... . B. Reset contacts. C. Upper set of "LVa" contacts. D. Lower set of "LVa" contacts.

Last Answer : Answer: C

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

Which of the devices shown in the illustration automatically prevents the simultaneous operation of the windlass from both master switches? EL-0073 A. Selector switch B. Contact 'CR1a' C. Contact 'CR2a' D. Contact 'CR1D'

Description : Which of the devices shown in the illustration automatically prevents the simultaneous operation of the windlass from both master switches? EL-0073 A. Selector switch B. Contact 'CR1a' C. Contact 'CR2a' D. Contact 'CR1D'

Last Answer : Answer: D

When an operating motor is connected to the controller shown in the illustration, the a path of current flow through the circuit is ____________. EL-0010 A. 'L1', stop button, start button, coil 'CR', 'L2' B. 'L1', stop button, 'CR' and 'M' contacts, 'M' coil, 'OL contacts, the 'CR' coil in parallel, 'L2' C. 'L1', stop button, jog button, 'CR' contact, 'CR' relay, 'L2' D. 'L1', stop button, start button, 'CR' contact, 'M' contact, 'CR' coil, 'L2'

Description : When an operating motor is connected to the controller shown in the illustration, the a path of current flow through the circuit is ____________. EL-0010 A. 'L1', stop button, start button, coil 'CR', 'L2' B. 'L1' ... L2' D. 'L1', stop button, start button, 'CR' contact, 'M' contact, 'CR' coil, 'L2'

Last Answer : Answer: B

When the motor shown in the illustration is running and the stop button is pushed, which of the following statements will hold true? EL-0010 A. Coil 'M' will now be energized. B. Coil 'CR' will now be energized. C. Contact 'M' will close as contact 'CR' opens. D. Contacts 'M' and 'CR' will open.

Description : When the motor shown in the illustration is running and the stop button is pushed, which of the following statements will hold true? EL-0010 A. Coil 'M' will now be energized. B. Coil 'CR' will now be energized. C. Contact 'M' will close as contact 'CR' opens. D. Contacts 'M' and 'CR' will open.

Last Answer : Answer: D

As shown in the illustration, which of the operations listed will happen when the 'jog button' is pushed? EL-0010 A. Coil 'CR' closes the normally open 'CR' contacts. B. Coil 'M' opens contact 'M'. C. Coil 'M' closes contact 'M'. D. Contact 'M' remains open despite the jog button being pushed.

Description : As shown in the illustration, which of the operations listed will happen when the 'jog button' is pushed? EL-0010 A. Coil 'CR' closes the normally open 'CR' contacts. B. Coil 'M' opens contact 'M'. C. Coil 'M' closes contact 'M'. D. Contact 'M' remains open despite the jog button being pushed.

Last Answer : Answer: C

As shown in the illustration, which listed action will occur first when push button 'Q' is depressed? EL-0017 A. Contacts 'H-1', 'H-2' and 'H-3' close. B. Contact 'H-4' closes. C. Operating coil 'C' energizes. D. Switch 'R' opens.

Description : As shown in the illustration, which listed action will occur first when push button 'Q' is depressed? EL-0017 A. Contacts 'H-1', 'H-2' and 'H-3' close. B. Contact 'H-4' closes. C. Operating coil 'C' energizes. D. Switch 'R' opens.

Last Answer : Answer: C

If the motor shown in the illustration will not start when 'Q' is depressed, which of the listed components should be checked FIRST? EL-0017 A. Fuses 'F-1' and 'F-2'. B. Operating coil 'C'. C. Contacts 'H-1', 'H-2', and 'H-3'. D. Contact 'H-4'.

Description : If the motor shown in the illustration will not start when 'Q' is depressed, which of the listed components should be checked FIRST? EL-0017 A. Fuses 'F-1' and 'F-2'. B. Operating coil 'C'. C. Contacts 'H-1', 'H-2', and 'H-3'. D. Contact 'H-4'.

Last Answer : Answer: A

Etched or burned bands on the contact faces of the brushes in a direct current generator can be caused by ____________. A. high mica segments B. copper drag on the commutator C. brushes improperly positioned D. copper embedded in the brushes

Description : Etched or burned bands on the contact faces of the brushes in a direct current generator can be caused by ____________. A. high mica segments B. copper drag on the commutator C. brushes improperly positioned D. copper embedded in the brushes

Last Answer : Answer: C

If the circuit shown in the illustration were energized and operating properly, which of the devices listed would be open? EL-0007 A. The stop push-button B. The start push-button C. Contact 'Ma' D. Contact 'OL1'

Description : If the circuit shown in the illustration were energized and operating properly, which of the devices listed would be open? EL-0007 A. The stop push-button B. The start push-button C. Contact 'Ma' D. Contact 'OL1'

Last Answer : Answer: B

As shown in the illustration, which of the symbols represents a normally closed electrical contact? EL-0005 A. A B. B C. C D. D

Description : As shown in the illustration, which of the symbols represents a normally closed electrical contact? EL-0005 A. A B. B C. C D. D

Last Answer : Answer: A

What is represented by the electric symbol figure 'D' in the illustration? EL-0005 A. Fuse B. Plug-in contact resistor C. Variable capacitor D. Electrolytic capacitor

Description : What is represented by the electric symbol figure 'D' in the illustration? EL-0005 A. Fuse B. Plug-in contact resistor C. Variable capacitor D. Electrolytic capacitor

Last Answer : Answer: A

As part of a routine maintenance program for deck machinery, you should ___________. A. inspect electrical wiring and pushbutton switches for evidence of corrosion or burned insulation B. disassemble pushbutton switches and drain water each week C. remove motor covers and ventilate as weather permits D. Check drum switch contact pressure every three months

Description : As part of a routine maintenance program for deck machinery, you should ___________. A. inspect electrical wiring and pushbutton switches for evidence of corrosion or burned insulation B. disassemble ... covers and ventilate as weather permits D. Check drum switch contact pressure every three months

Last Answer : Answer: A

A circuit that has one of two wires in contact with the hull of a ship, is called a _____________. A. grounded circuit B. short circuit C. series circuit D. closed circuit

Description : A circuit that has one of two wires in contact with the hull of a ship, is called a _____________. A. grounded circuit B. short circuit C. series circuit D. closed circuit

Last Answer : Answer: A

A current-carrying conductor making electrical contact with a wiring conduit will be indicated by a _____________. A. high switchboard wattmeter reading B. totally dark switchboard ground detecting light C. low switchboard wattmeter reading D. all of the above

Description : A current-carrying conductor making electrical contact with a wiring conduit will be indicated by a _____________. A. high switchboard wattmeter reading B. totally dark switchboard ground detecting light C. low switchboard wattmeter reading D. all of the above

Last Answer : Answer: B

In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 6 reads line voltage, while the voltmeter reading between 2 and 6 reads 0 VAC. The problem is __________. EL-0007 A. the control fuse is the wrong amperage not allowing full current to pass through B. the stop switch is open C. an open in the 'M' coil, 'Ma' contact/start switch or overload contacts D. fuse '10a' is blown

Description : In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 6 reads line voltage, while the voltmeter reading between 2 and 6 reads 0 VAC. The problem is __________. EL- ... in the 'M' coil, 'Ma' contact/start switch or overload contacts D. fuse '10a' is blown

Last Answer : Answer: B

As shown in the illustration, what is responsible for maintaining the "LV" relay energized when the master switch handle is moved away from the "off" position? EL-0102 A. "DBa" contact. B. Reset contacts. C. Upper set of "LVa" contacts. D. Lower set of "LVa" contacts.

Description : As shown in the illustration, what is responsible for maintaining the "LV" relay energized when the master switch handle is moved away from the "off" position? EL-0102 A. "DBa" contact. B. Reset contacts. C. Upper set of "LVa" contacts. D. Lower set of "LVa" contacts.

Last Answer : Answer: C

In addition to short circuits and sustained overloads, fuses are likely to blow due to _____________. A. loose fuse clips B. low ambient temperatures C. low contact resistance D. all of the above

Description : In addition to short circuits and sustained overloads, fuses are likely to blow due to _____________. A. loose fuse clips B. low ambient temperatures C. low contact resistance D. all of the above

Last Answer : Answer: A

A current-carrying conductor makes accidental contact with a wiring conduit. This will be indicated by a _____________. A. low switchboard wattmeter reading B. high switchboard wattmeter reading C. darkened switchboard ground detecting lamp D. darkened switchboard synchronizing lamps

Description : A current-carrying conductor makes accidental contact with a wiring conduit. This will be indicated by a _____________. A. low switchboard wattmeter reading B. high switchboard wattmeter reading C. darkened switchboard ground detecting lamp D. darkened switchboard synchronizing lamps

Last Answer : Answer: C

A current carrying conductor making an electrical contact with a wiring metal conduit is indicated by a _____________. A. low switchboard wattmeter reading B. reading of 1.0 on the power factor meter C. high switchboard voltmeter reading D. totally darkened switchboard ground-detecting light

Description : A current carrying conductor making an electrical contact with a wiring metal conduit is indicated by a _____________. A. low switchboard wattmeter reading B. reading of 1.0 on the power factor meter C. high switchboard voltmeter reading D. totally darkened switchboard ground-detecting light

Last Answer : Answer: D

In the illustration, the component labeled D is a ______. EL-0033 A. fixed contact B. moving contact C. trip bar D. bimetallic strip

Description : In the illustration, the component labeled D is a ______. EL-0033 A. fixed contact B. moving contact C. trip bar D. bimetallic strip

Last Answer : Answer: B

The winch shown in the illustration operates in any of the positions with the master switch in the 'lower' direction, but will not 'hoist' in any of the master switch hoist positions. Which of the listed faults could be the cause? EL-0102 A. Master switch contact 'MS3' may have defective springs. B. Contactor '3M' coil could have an open winding. C. Contact '2M' in the power circuit may be badly corroded. D. Series relay 'FR' may be open.

Description : The winch shown in the illustration operates in any of the positions with the master switch in the 'lower' direction, but will not 'hoist' in any of the master switch hoist positions. Which of the listed faults ... '2M' in the power circuit may be badly corroded. D. Series relay 'FR' may be open.

Last Answer : Answer: A

In the illustration the component C is the ____________. EL-0033 A. fixed contact B. moving contact C. connection terminal D. trip bar

Description : In the illustration the component C is the ____________. EL-0033 A. fixed contact B. moving contact C. connection terminal D. trip bar

Last Answer : Answer: A

In the illustration, the the device E is the______. EL-0033 A. bimetal strip B. moving contact C. trip bar D. handle

Description : In the illustration, the the device E is the______. EL-0033 A. bimetal strip B. moving contact C. trip bar D. handle

Last Answer : Answer: C

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 plates that interacts with the arc to cool and extinguish the arc C. cause the contacts to open in the event of an overload D. provide ventilation to the contact when the breaker is close to rated capacity

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

In order to prevent the winch shown in the illustration from turning while troubleshooting the controller circuit, _________________. EL-0102 A. set the dynamic brake by clamping contact 'DB' closed B. set the mechanical brake by the jackscrew provided C. disconnect the brake solenoid at 'B1' and 'B2' D. open the test link preventing current flow to the armature

Description : In order to prevent the winch shown in the illustration from turning while troubleshooting the controller circuit, _________________. EL-0102 A. set the dynamic brake by clamping contact 'DB' closed B. set the ... at 'B1' and 'B2' D. open the test link preventing current flow to the armature

Last Answer : Answer: D

During maintenance of circuit breakers, _______________. A. always smooth roughened contact surfaces with a file B. never pass more than rated breaker current through the overload heater element C. inspect for wear and misalignment of main contacts D. assume heater elements installed are of correct size

Description : During maintenance of circuit breakers, _______________. A. always smooth roughened contact surfaces with a file B. never pass more than rated breaker current through the overload heater element C. ... wear and misalignment of main contacts D. assume heater elements installed are of correct size

Last Answer : Answer: C

The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor

Description : The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor

Last Answer : Answer: C

The air gap in an induction motor should be periodically checked with a feeler gage to prevent possible ___________. A. rotor contact with the stator B. axial misalignment of the rotor C. damage to the motor bearings D. electrical damage to the bearings

Description : The air gap in an induction motor should be periodically checked with a feeler gage to prevent possible ___________. A. rotor contact with the stator B. axial misalignment of the rotor C. damage to the motor bearings D. electrical damage to the bearings

Last Answer : Answer: A

The motor starts when the start button in the illustration is pushed, but stops when the button is released the trouble is _________. EL-0007 A. the incorrect thermal overload coil B. a faulty 'M' coil C. a dirty contact on the Disc.Sw. at 'L3' D. a faulty holding relay contact

Description : The motor starts when the start button in the illustration is pushed, but stops when the button is released the trouble is _________. EL-0007 A. the incorrect thermal overload coil B. a faulty 'M' coil C. a dirty contact on the Disc.Sw. at 'L3' D. a faulty holding relay contact

Last Answer : Answer: D

In the illustration the symbol for an N/O contact is_______. EL-0005 A. A B. B C. C D. D

Description : In the illustration the symbol for an N/O contact is_______. EL-0005 A. A B. B C. C D. D

Last Answer : Answer: B

Propulsion DC motor brush pressures can be calculated by _____________. A. dividing the brush contact area by the spring pressure B. subtracting the brush contact area from the spring pressure C. dividing the spring force by the brush contact area D. subtracting the spring pressure from the brush contact area

Description : Propulsion DC motor brush pressures can be calculated by _____________. A. dividing the brush contact area by the spring pressure B. subtracting the brush contact area from the spring pressure C. ... force by the brush contact area D. subtracting the spring pressure from the brush contact area

Last Answer : Answer: C

The small circular symbols to which wire '52N57E' is connected at coordinates '57L' and '57P' shown in the illustration represent ___________________. EL-0100 A. relay contact solder points B. wire wrap connections C. terminal board screws D. switch contact terminals

Description : The small circular symbols to which wire '52N57E' is connected at coordinates '57L' and '57P' shown in the illustration represent ___________________. EL-0100 A. relay contact solder points B. wire wrap connections C. terminal board screws D. switch contact terminals

Last Answer : Answer: C