What is Under-voltage protection?

1 Answer

Answer :

It prevents closure of the breaker by mistake, or the generator that is coming on load during parallel operation. It also provides protection against loss of voltage while machinery is connected to the switchboard.

Related questions

Description : How is protection provided for OL and SC?

Last Answer : Damage from short circuits and overloads can be reduced or prevented by employing fuses, circuiDamage from short circuits and overloads can be reduced or prevented by employing fuses, circuit breakers, or other overload ... (a few seconds) due to currents say 1.1 to 1.5 times the normal current.

Description : How is the protection against reverse power given?

Last Answer : Reverse power protection is used for anti-motoring. This function is used for protection of prime mover not generator. It can cut-off the fuel supply and stop the prime mover.

Description : What is the speaker driving voltage of an amplifier?

Last Answer : I have to ask WHY? That said, Speakers and a light bulb are two different types of load, and the the lights will probably fry the output transistor.

Description : What is a current transformer and voltage transformer?*

Last Answer : In electrical engineering, a current transformer (CT) is used for measurement of electric currents. Current transformers, together with voltage transformers (VT) (potential transformers (PT)), ... transformers are commonly used in metering and protective relays in the electrical power industry.

Description : How is this voltage achieved?

Last Answer : By connecting 12 cells in series. 12 x 2 V = 24 V is total battery bank voltage.

Description : What is the full battery voltage ?

Last Answer : 24 V DC.

Description : What is the voltage available from each cell in a lead acid battery?

Last Answer : 2 V DC.

Description : What is safe voltage to prevent shock?

Last Answer : Normally 50V. It depends on the body resistance and how conducting the path is (example use of insulating boots or mat may allow slightly higher voltage to be safe)

Description : What is the voltage used for ignition in boilers/incinerators etc.?

Last Answer : Normally 10,000V (10kV). But ask E/O to confirm.

Description : What is the voltage?

Last Answer : Ask E/O on your ship.

Description : What is the voltage used in a meggar?

Last Answer : 500V DC.

Description : The wavelength of the wave associated with the moving object is a) Directly proportional to the accelerating voltage b) Directly proportional to the square of accelerating voltage c) ... proportional to the square root of accelerating voltage d) Inversely proportional to the accelerating voltage

Last Answer : c) Inversely proportional to the square root of accelerating voltage

Description : The output from a full wave rectifier is (a) A pulsating uni-directional current (b) A DC voltage (c) Zero (d) An AC voltage

Last Answer : a) A pulsating uni-directional current

Description : Devices which convert various physical quantities into electrical voltage are known as (a) Control system (b) sensors (c) level sensors (d) LDR

Last Answer : (b) sensors

Description : A sensor which changes light intensity into electric voltage. (a) LDR (b) thermistor (c) photodiode (d) photovoltaic

Last Answer : (a) LDR

Description : Process of conversion low voltage to high voltage is called _______ (a) Rectification (b)forward bias (c) reverse bias (d) amplification

Last Answer : (d) amplification

Description : The most common source of AC voltage is: a. motor b. generator c. cell d. transformer

Last Answer : c. cell

Description : Turn ratio of a transformer is 5. If 220 V AC is applied to its primary coil, voltage in the secondary coil will be: a. 44V b. 4.4 V c. 220V d. 1100V

Last Answer : c. 220V

Description : A circuit which develops voltage across the horizontal deflection plates is known as a) Time base generator b) Electron gun c) Thermionic diode d) Zener diode

Last Answer : a) Time base generator

Description : The fractional change in resistance per kelvin is known as, a. temperature coefficient of resistance b. coefficient of Voltage of charge c. thermal expansion d. all of above

Last Answer : a. temperature coefficient of resistance

Description : A fuse is placed in series with the cireuit to protect against a. high power b. high voltage c. high current d. over heating

Last Answer : d. over heating

Description : Refer to the circuit below. The voltage V2, is equal to:

Last Answer : The answer to this question is -3V. Because 3V is in parallel with v2 and voltages in parallel are equal. But it is in opposite direction so the answer is -3V.

Description : Why is it cheaper to transmit electrical energy at high voltage?

Last Answer : Because of the electrical energy was step upped by transformers the transformer have high efficiency than the electric energy is cheaper

Description : Themechanicalsplice isbestsuited for a. quicker installation under ideal conditions b. minimum attenuation losses c. field service conditions d. situations in which cost of equipment is not a factor

Last Answer : c. field service conditions

Description : Under ideal conditions, the collector current is (a) Equal to base current (b) Nearly equal to emitter current (c) Less than base current (d) always zero

Last Answer : (b) Nearly equal to emitter current

Description : Depletion region of a junction is formed _________ (a) during the manufacturing process (b) under forward bias (c) under reverse bias (d) when temperature varies

Last Answer : (a) during the manufacturing process

Description : Explain protection of locomotive from overvoltage and under voltage

Last Answer : Protection of Locomotive From Overvoltage and Under Voltage: 1. For protection against over voltages the over voltage relay which is basically a potential transformer (PT) is used. 2. ... a relay triggering an alarm, which enables the power controller to react and take corrective measures.

Description : State the nature of protection provided for following types of faults; 1) Over voltage 2) Under voltage 3) High air pressure in air circuit 4) Low air pressure in air circuit

Last Answer : Ans:  1) Over voltage: Controlled through tap changing, only an alarm needs to be provided for attention of crew.  2) Under voltage: voltage below 17.5 kV is not desirable. A no volt ... 4) Low air pressure in air crcuit: Relay senses low pressure in air circuit and trips the relevant CB.

Description : Please ripley me due to emergency

Last Answer : To calculate the flux density in the ring, you need to use the following formula: B = (μ * I * N) / (2 * π * r) where: B is the flux density in the ring (in teslas) μ is the relative permeability ... 2 * π * 0.127 m) = 0.53 T So the flux density in the ring would be approximately 0.53 teslas.

Description : Can you help me solve my electrical mystery?

Last Answer : Any signs of animal life? They can get in the walls and chew on the wires. Or is it the entire area served by that breaker? The breaker could be bad. It happens with anything mechanical.

Description : How to tell if a power strip is burned out?

Last Answer : answer:Personally, I would either toss it, or down grade it to outdoor use only. I wouldn’t take a chance with it in the house. Yes, you can let it cool down, then test it again. But a failure is a failure. Does it have a reset button? What price range did you pay?

Description : I accidently soaked an extension cord. Is it safe to use it again after letting it dry out for awhile?

Last Answer : The plug end is easier to dry out than the socket end get out your blow-dryer and set it to high and blow the end that got wet for a while. That will get most of the water off/out of ... up or sputter. Most modern extension cords are pretty watertight so there shouldn't be any water down the wire.

Description : How can a solar array power source be bypassed when the batteries run low?

Last Answer : Ah got it. If anyone else is interested, you need an “automatic transfer switch” – or get a manual one for that mad scientist charm.

Description : How to stop a signal going through a wire?

Last Answer : Use a switch or a variable resistor

Description : Air conditioning will not turn on, is it electrical?

Last Answer : Pull the Thermostat off the wall and see if it is connected correctly to the AC switch. There should be no dangling wires, and the post labeled for the AC should have an attached wire.

Description : Why is my Garbage disposal leaking water from the bottom?

Last Answer : Replace it. The seal is leaking, and most cases it is just not worth the cost and work, quicker and cheaper to replace it .

Description : Have you ever taken a shower or bath during an electrical storm?

Last Answer : I’ve heard this rumor, and I too question it’s validity. I mean, if electricity can’t travel up a stream of urine (See mythbusters) I’m pretty sure it couldn’t travel through a shower stream. Perhaps through the drain? In either case, I’ve taken a shower in a storm before, and.. well, you see?

Description : Electrical breaker box is buzzing-why??

Last Answer : No! Do not upgrade the breaker. The wire must also be upgraded if you do. Try plugging it in a different room. Is the problem still there?

Last Answer : Laptop Yes A Portable Computer.

Last Answer : electricity Source , conductor , control Instruments , Usage Machines , Protection Machines In combination Such A Path Whose The middle With Current Flowing To be Can Him Circuit Or Circuit Says.

Last Answer : House Wiring Mainly Two Type. A ) Surface Wiring B ) Concealed Wiring Surface Wiring 5 Type : 1 ) Batten Wiring 2 ) Conduit Wiring 3 ) Clit Wiring 4 ) Casing Wiring 5 ) M. S. Wiring Concealed Wiring Again Two Type , 1 ) Concealed Conduit 2 ) Concealed Wire Wiring

Last Answer : any Conductive The middle With One Ampere Flow One Seconds Hold on Let's go Of Any Cross section With That Amount Infusion Flowing Is Him One Coulomb Says.

Last Answer : that At the rate Electron Flowing Become Work Done Is Or That At the rate Electricity Power Other In strength Transformed Is Him Electric Power Says.

Last Answer : any Person Or Of the object Single In time Made Of work The amount Power Says.

Last Answer : any Magnetic In the case A Isolated The answer To the pole In the free state Placement If you do The pole That Path Circulation By Him Magnetic Ball line Says.

Last Answer : that Features Or Of religion Due As well as Two Coil Of one Of current Of change As a result In the other Voltage Obsessed Is That said Religion Or Features Mutual Inductions Says.

Last Answer : Cable Being Electric Conductive His Whose The middle With Current Movement By

Last Answer : her And Cable In The difference Yes His Yes Just Only A Conductor Where Cable Two Or Even more Of the conductor A Group.

Last Answer : Wire Through In load ( e.g. fan , lamp ) Etc. ) electric Power Supply To do Ordinary To the system Electric Waring Says. General In a sense Load Electric Power Supply To do For Of wires Ordinary In the system Being Electric Waring.

Last Answer : Operating Of the system Of work Basic Single Who Process Says.