Discuss
menu
search
person
Login
Register
search
edit
Ask a Question
Discuss
All Activity
Q&A
Questions
Hot!
Unanswered
Tags
Users
Ask a Question
Other
Protection by fuses is generally not used beyond?
asked
Mar 20, 2018
by
anonymous
protection
fuses
thumb_up_alt
0
like
thumb_down_alt
0
dislike
133
views
Please
log in
or
register
to add a comment.
Please
log in
or
register
to answer this question.
1
Answer
answered
Mar 20, 2018
by
anonymous
Protection by fuses is generally not used beyond
100 A
.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
Please
log in
or
register
to add a comment.
← Prev Question
Next Question →
Related questions
asked
Mar 20, 2018
by
anonymous
The delay fuses are used for the protection of?
Last answer:
The delay fuses are used for the protection of motors.
delay
fuses
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
75
views
1
answer
asked
Mar 20, 2018
by
anonymous
H.R.C. fuses provide best protection against?
Last answer:
H.R.C. fuses provide best protection against short-circuits.
hrc
fuses
thumb_up_alt
0
like
thumb_down_alt
0
dislike
75
views
1
answer
asked
Apr 30, 2018
by
anonymous
The material used in liquid fuses is
The material used in liquid fuses is (1) SF6 (3) carbon tetra chloride (2) distilled water (4) transformer oil
Last answer:
The material used in liquid fuses is carbon tetra chloride
material
used
liquid
fuses
thumb_up_alt
0
like
thumb_down_alt
0
dislike
252
views
1
answer
asked
May 8, 2018
by
anonymous
A relay used for protection of motors against overload is :
A relay used for protection of motors against overload is : (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay
Last answer:
A relay used for protection of motors against overload is : Thermal relay
relay
used
protection
motors
overload
thumb_up_alt
0
like
thumb_down_alt
0
dislike
218
views
1
answer
asked
May 1, 2018
by
anonymous
A negative sequence relay is used for protection of
A negative sequence relay is used for protection of (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines
Last answer:
A negative sequence relay is used for protection of Generator
negative
sequence
relay
used
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
454
views
1
answer
asked
Apr 30, 2018
by
anonymous
For protection of rotating machines against lightning surges _______ is used.
For protection of rotating machines against lightning surges _______ is used. (1) lightning arrester (2) capacitor (3) combination of lightning arrester and capacitor (4) lightning conductor and arrester
Last answer:
For protection of rotating machines against lightning surges combination of lightning arrester and capacitor is used.
protection
rotating
machines
lightning
surges
thumb_up_alt
0
like
thumb_down_alt
0
dislike
4.0k
views
1
answer
asked
Mar 20, 2018
by
anonymous
Discrimination between main and backup protection is provided by the use of relays which are?
Last answer:
Discrimination between main and back up protection is provided by the use of relays which are slow.
discrimination
between
main
backup
protection
use
relays
thumb_up_alt
0
like
thumb_down_alt
0
dislike
303
views
1
answer
asked
Apr 26, 2018
by
anonymous
Surge absorbers are used for protection against
Surge absorbers are used for protection against
Last answer:
Surge absorbers are used for protection against low voltage high frequency oscillations
surge
absorbers
used
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.9k
views
1
answer
asked
Mar 20, 2018
by
anonymous
The inverse definite mean time relays are used for over current and earth fault protection of transformer against?
Last answer:
The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.
inverse
definite
mean
time
relays
used
over
current
earth
fault
protection
transformer
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.5k
views
1
answer
asked
Mar 20, 2018
by
anonymous
The single phasing relays are used for the protection of?
Last answer:
The single phasing relays are used for the protection of three phase motors.
single
phasing
relays
used
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
131
views
1
answer
asked
May 8, 2018
by
anonymous
Blind spot is a point in the zones of protection where
Blind spot is a point in the zones of protection where
Last answer:
Blind spot is a point in the zones of protection where No protection is available.
blind
spot
point
zones
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
576
views
1
answer
asked
Apr 29, 2018
by
anonymous
Reactance relay is normally preferred for protection against
Reactance relay is normally preferred for protection against
Last answer:
Reactance relay is normally preferred for protection against earth faults
reactance
relay
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
71
views
1
answer
asked
Mar 20, 2018
by
anonymous
Overfluxing protection is recommended for?
Last answer:
Overfluxing protection is recommended for generator transformer of the power plant.
overfluxing
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
56
views
1
answer
asked
Mar 20, 2018
by
anonymous
Over voltage protection is recommended for?
Last answer:
Over voltage protection is recommended for hydro-electric generators, steam turbine generators, gas turbine generators.
over
voltage
protection
recommended
thumb_up_alt
0
like
thumb_down_alt
0
dislike
63
views
1
answer
asked
Mar 20, 2018
by
anonymous
A fuse in a motor circuit provides protection against?
Last answer:
A fuse in a motor circuit provides protection against short-circuit and overload.
fuse
motor
circuit
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
111
views
1
answer
asked
Mar 20, 2018
by
anonymous
For the protection of power station buildings against direct strokes the requirements are?
Last answer:
For the protection of power station buildings against direct strokes the requirements are interception, conduction and dissipation.
protection
power
station
direct
strokes
thumb_up_alt
0
like
thumb_down_alt
0
dislike
58
views
1
answer
asked
Mar 19, 2018
by
anonymous
A thermal protection switch can protect against?
Last answer:
A thermal protection switch can protect against overload.
thermal
protection
switch
protect
thumb_up_alt
0
like
thumb_down_alt
0
dislike
175
views
1
answer
asked
Aug 9, 2017
by
anonymous
Primary and Backup Protection
Primary and Backup Protection
Last answer:
Primary and Backup Protection B,D,G,I are the primary protection. A,C,H,J are the backup protection. About 90% of faults are clear by Primary Protection. So ... ordinated backup (primary is at various station and backup is at control room with computer)
primary
backup
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
351
views
1
answer
asked
Sep 1, 2018
by
anonymous
Fuse wire protection system is usually not used beyond: a. 10A b. 25A c. 50A d. 100A
Fuse wire protection system is usually not used beyond: a. 10A b. 25A c. 50A d. 100A
Last answer:
Fuse wire protection system is usually not used beyond: a. 10A b. 25A c. 50A d. 100A
thumb_up_alt
0
like
thumb_down_alt
0
dislike
46
views
1
answer
asked
Jul 25, 2019
by
anonymous
Explain in detail over-voltage protection.
Explain in detail over-voltage protection.
Last answer:
Over-voltage protection: Over-voltage protection to the thyristor is provided using: i) R-C Snubber circuit ii) Non-linear resistor Thyrector A) Snubber Circuit: It is basically a ... returns to its high resistance state. Thyrector is normally placed across the supply terminals.
over-voltage
protection
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.5k
views
1
answer
asked
May 12, 2018
by
anonymous
The type of backup protection scheme widely used in the field is
The type of backup protection scheme widely used in the field is (A) Relay backup (B) Breaker backup (C) Remote backup (D) Auxiliary backup
Last answer:
The type of backup protection scheme widely used in the field is Remote backup
thumb_up_alt
0
like
thumb_down_alt
0
dislike
918
views
1
answer
asked
Jun 4, 2018
by
anonymous
Protection of transformer from all types of faults is by using
Protection of transformer from all types of faults is by using (A) over current relay (B) differential relay (C) distance relay (D) Buchholz relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
102
views
0
answers
asked
Jun 23, 2020
by
anonymous
Explain the “Differential Protection Scheme” used for alternators with neat labeled diagram.
Explain the “Differential Protection Scheme” used for alternators with neat labeled diagram.
Last answer:
Differential Protection Scheme for Alternator: Figure shows the differential protection provided to 3 phase alternator. Here identical CTs are placed on both sides of 3 phase alternator and ... causing its operation. Relay sends trip signal to the CB, thereby alternator circuit is tripped.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
19
views
1
answer
asked
Jun 4, 2018
by
anonymous
For the protection of parallel feeders fed from one end, the relays used are:
For the protection of parallel feeders fed from one end, the relays used are: A) non-directional relays at the source-end and directional relays at the load-end B) non-directional relays at both the ends C) directional relays at the source-end and non-directional at the load-end D) directional relays at both the ends
Last answer:
For the protection of parallel feeders fed from one end, the relays used are: non-directional relays at the source-end and directional relays at the load-end
thumb_up_alt
0
like
thumb_down_alt
0
dislike
234
views
1
answer
asked
May 13, 2018
by
anonymous
Transmission of power by a.c. cables is impossible beyond
Transmission of power by a.c. cables is impossible beyond (a) 500 km (b) 300 km (c) 250 km (d) 45 km
Last answer:
D
thumb_up_alt
0
like
thumb_down_alt
0
dislike
247
views
2
answers
asked
Apr 10, 2018
by
anonymous
Kick fuses are used across relay coils to prevent relay operation during
Kick fuses are used across relay coils to prevent relay operation during (a) Heavy external faults (b) Inrush current of transformer when they are energised (c) Line to ground faults (d) Bolted faults
thumb_up_alt
0
like
thumb_down_alt
0
dislike
105
views
0
answers
asked
Jun 4, 2018
by
anonymous
Which type of protection is provided on a generator to protect against stator insulation failure?
Which type of protection is provided on a generator to protect against stator insulation failure? A) Differential protection B) Overcurrent relay C) Thermocouple actuated alarm D) Reverse power relay
Last answer:
Which type of protection is provided on a generator to protect against stator insulation failure? A) Differential protection B) Overcurrent relay C) Thermocouple actuated alarm D) Reverse power relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
256
views
1
answer
asked
May 13, 2018
by
anonymous
In order to quench the are quickly and also optimize the dimensions generally
In order to quench the are quickly and also optimize the dimensions generally (a) Air blast C.B. is preferred (b) Oil C.B. is preferred (c) SF6 C.B. is preferred (d) Minimum oil C.B. is preferred
Last answer:
In order to quench the are quickly and also optimize the dimensions generally SF6 C.B. is preferred
thumb_up_alt
0
like
thumb_down_alt
0
dislike
614
views
1
answer
asked
Jun 23, 2020
by
anonymous
Explain with neat sketch, the Pilot wire protection scheme applied to transmission line.
Explain with neat sketch, the Pilot wire protection scheme applied to transmission line.
Last answer:
Pilot Wire Protection scheme of Transmission Line : Figure shows the single line diagram of Merz price voltage balance system for pilot wire protection of three phase transmission line. ... through the relay, which gives trip signal to the circuit breaker for protection of transmission line.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
77
views
1
answer
asked
Jun 23, 2020
by
anonymous
Explain differential protection scheme for busbars with neat sketch.
Explain differential protection scheme for busbars with neat sketch.
Last answer:
Differential Protection Scheme for Bus bar: Under normal conditions, the sum of the currents entering the bus bar zone is equal to those leaving it and no current flows through the relay ... of these currents will flow through the relay coil causing opening of circuit breaker of bus-bar.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
15
views
1
answer
asked
Jun 23, 2020
by
anonymous
Discuss in brief the principle of distance protection and state four advantages of distance protection scheme.
Discuss in brief the principle of distance protection and state four advantages of distance protection scheme.
Last answer:
Advantages: 1. System is economical 2. High speed of interruption 3. Suitable for very long and high voltage transmission lines. 4. No problem of pilot wires.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
22
views
1
answer
asked
Jun 23, 2020
by
anonymous
State two requirements of transmission line protection.
State two requirements of transmission line protection.
Last answer:
Requirements of Transmission Line Protection: 1) Faults on lines should be quickly detected to initiate actions to maintain system stability. 2) For very long lines the protection system must be capable ... backup protection in the event of failure of circuit breaker (nearest to fault) to operate.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
17
views
1
answer
asked
Jun 23, 2020
by
anonymous
List two limitations of Differential-Protection scheme for transformer.
List two limitations of Differential-Protection scheme for transformer.
Last answer:
Limitations of Differential Protection Scheme of Transformer: 1) Due to the magnetization characteristics of the CTs used, the ratio errors change with respect to the circulating currents. 2) ... & improper operation. 5) Inrush of magnetizing current may lead to inadvertent operation.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
58
views
1
answer
asked
Jul 21, 2019
by
anonymous
Explain differential protection of busbar.
Explain differential protection of busbar.
Last answer:
Differential protection Scheme for bus bar: Under normal conditions the sum of the currents entering the bus bar zone is equal to those leaving it and no current flows through the relay ... . The difference of these currents will flow through the relay coil causing opening of circuit breaker.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
5.0k
views
1
answer
asked
Jul 21, 2019
by
anonymous
Explain over-current protection of transformer.
Explain over-current protection of transformer.
Last answer:
Over-Current Protection of Transformer: Simple over-current & earth fault protection of transformer against external shortcircuit and excessive overloads is shown in the above figure. The ... trip command to the circuit breaker and the transformer is disconnected from load or fault.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2.5k
views
1
answer
asked
Jul 21, 2019
by
anonymous
Explain negative phase sequence protection of alternator.
Explain negative phase sequence protection of alternator.
Last answer:
Negative phase sequence protection of alternator: Unbalanced loading on alternator mainly causes the negative sequence currents which generate the negative sequence components of magnetic fields. These fields ... components due to unbalance and operates the relay which further operates CB.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
64
views
1
answer
asked
Jul 21, 2019
by
anonymous
Explain fault bus protection scheme.
Explain fault bus protection scheme.
Last answer:
Fault bus protection of busbar: In this scheme, the substation is so designed that every fault on the bus bar is converted to earth fault. Under normal operating conditions, there is no current flowing ... This results in operation of relay to actuate trip coil of CB to trip the circuit.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
65
views
1
answer
asked
Jul 21, 2019
by
anonymous
Explain distance protection of transmission line with neat sketch diagram.
Explain distance protection of transmission line with neat sketch diagram.
Last answer:
Distance protection of Transmission line: Distance protection scheme uses impedance relay. The relay operation is based on the impedance (or distance) between the relay and point of fault. Figure shows ... than ZL and impedance relay operates which operates the CB and line is protected.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
77
views
1
answer
asked
Jul 21, 2019
by
anonymous
Write down limitation of differential protection of transformer.
Write down limitation of differential protection of transformer.
Last answer:
Limitations of differential protection of transformer: 1) Due to the magnetization characteristics of the CTs used, the ratio errors change with respect to the circulating currents. 2) The pilot wires ... current (higher imbalance) due to which accuracy of sensing & operation is decreased.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
4.9k
views
1
answer
asked
Jul 21, 2019
by
anonymous
How can we use CT and PT for protection purpose?
How can we use CT and PT for protection purpose?
Last answer:
CT and PT for Protection purpose: Current transformer (CT) and Potential transformer (PT) are instrument transformers, which are used in conjunction with protective relays for protection purpose. The CT ... from the healthy part. In this way the CT and PT can be used for protection purpose.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
63
views
1
answer
asked
Jun 17, 2018
by
anonymous
For complete protection of a three-phase line:
For complete protection of a three-phase line: A) three Phase relays and three Earth fault relays are required B) three Phase relays and two Earth fault relays are required C) two Phase relays and two Earth fault relays are required D) two Phase relays and one Earth fault relay are required
Last answer:
For complete protection of a three-phase line: two Phase relays and one Earth fault relay are required
thumb_up_alt
0
like
thumb_down_alt
0
dislike
89
views
1
answer
asked
May 24, 2018
by
anonymous
A loss of excitation protection scheme for large generating unit employs
A loss of excitation protection scheme for large generating unit employs A) under frequency relays B) offset Mho relay C) reactance relay D) percentage differential relay
Last answer:
A loss of excitation protection scheme for large generating unit employs offset Mho relay
thumb_up_alt
0
like
thumb_down_alt
0
dislike
54
views
1
answer
asked
May 22, 2018
by
anonymous
For complete protection ofa 3-phase line:
For complete protection ofa 3— phase line: (1) Three phase and three—earth fault relays are required (2) Three phase and two—earth fault relays are required (3) Two phase and two—earth fault relays are required (4) Two phase and one-earth fault relays are required
Last answer:
For complete protection ofa 3— phase line: Two phase and one-earth fault relays are required
thumb_up_alt
0
like
thumb_down_alt
0
dislike
165
views
1
answer
asked
Mar 20, 2018
by
anonymous
Synchronous motors are generally not self-starting because?
Last answer:
Synchronous motors are generally not self-starting because the direction of instantaneous torque reverses after half cycle.
synchronous
motors
self-starting
thumb_up_alt
0
like
thumb_down_alt
0
dislike
59
views
1
answer
asked
4 days
ago
by
anonymous
Which among the following statements is true regarding International Date line ? (1) It is 180° Longitude (2) It is a straight line (3) It is a big circle (4) It is a curved line beyond earth
Which among the following statements is true regarding International Date line ? (1) It is 180° Longitude (2) It is a straight line (3) It is a big circle (4) It is a curved line beyond earth
Last answer:
It is 180° Longitude
physical-geography
thumb_up_alt
0
like
thumb_down_alt
0
dislike
2
views
1
answer
asked
Sep 1, 2018
by
anonymous
High-voltage testing equipment is generally used in
High-voltage testing equipment is generally used in a. Routine testing Laboratories b. Research Laboratories c. Both of the above d. None of the above
Last answer:
High-voltage testing equipment is generally used in a. Routine testing Laboratories b. Research Laboratories c. Both of the above d. None of the above
thumb_up_alt
0
like
thumb_down_alt
0
dislike
37
views
1
answer
asked
Jun 17, 2018
by
anonymous
Which motor is generally used in Tap Recorders?
Which motor is generally used in Tap Recorders? A) universal motor B) reluctance motor C) split phase motor D) hysteresis motor
Last answer:
Which motor is generally used in Tap Recorders? A) universal motor B) reluctance motor C) split phase motor D) hysteresis motor
thumb_up_alt
0
like
thumb_down_alt
0
dislike
55
views
1
answer
asked
May 24, 2018
by
anonymous
Assertion (A) : Wein bridge oscillator is generally used as a variable audio frequency oscillator Reason (R) :
Assertion (A) : Wein bridge oscillator is generally used as a variable audio frequency oscillator Reason (R) : by using either capacitor (or) resistor in one of the arms of the bridge, the frequency of a wein bridge oscillator can be varied (A) Both (A) & (R) are true & (R) is correct explanation of (A) (B) Both (A) & (R) are true but (R) is not the correct explanation of (R). (C) (A) is true but (R) is false (D) (A) is false but (R) is true
Last answer:
Assertion (A) : Wein bridge oscillator is generally used as a variable audio frequency oscillator Reason (R) : by using either capacitor (or) resistor in one of the arms of the bridge, the frequency of a wein bridge oscillator ... ) (A) is true but (R) is false (D) (A) is false but (R) is true
thumb_up_alt
0
like
thumb_down_alt
0
dislike
94
views
1
answer
asked
Apr 29, 2018
by
anonymous
The storage battery generally used in electric power stations is
The storage battery generally used in electric power stations is (1) zinc carbon battery (2) lead acid battery (3) nickel cadmium battery (4) lithium -ion battery
Last answer:
The storage battery generally used in electric power stations is lead acid battery
storage
battery
used
electric
power
stations
thumb_up_alt
0
like
thumb_down_alt
0
dislike
91
views
1
answer
asked
Apr 12, 2018
by
anonymous
Current ratings of MCB for Air conditioners is generally used as _________.
Current ratings of MCB for Air conditioners is generally used as _________. A. 10/15 Amp B. 5/10 A C. 20/25 Amp D. none of these
Last answer:
Current ratings of MCB for Air conditioners is generally used as 10/15 Amp.
thumb_up_alt
0
like
thumb_down_alt
0
dislike
85
views
1
answer
...