Question { 5227 }

break down of electricity is more in summer or in winter ?
give reason

Answer

My opinion is that the supply is less & demand is more of
electricity in summers etc.That is what country recently
faced grid faliure.

Question { 2757 }

if two transformers are parallel & both have fault short
ckt. impedance of 50KA in each case will it increase or
decrease show example?

Answer

it will definitely increase about 65% as in parallel i.e :-
1/R=1/R1+1/R2.

Question { 6346 }

How many points can we have in AC Circuit?
Show by giving suitable example?

Answer

12, which points light points or power points or both.

Question { The Grand, 4153 }

what is the principle of synchronous motors?

Answer

when ever a current carrying capacitor is placed in a
magnetic field torque is induced to rotate.

Question { San, 7156 }

HOW MUCH CURRENT CAN A 3 -1/2 CORE 100 MM WIRE CARRY

Answer

Mr.Keshav can u show the formula that will help us to
understand your answer easily?

Question { KPSC Karnataka Public Service Corporation, 4288 }

What is a doble test

Answer

The insulating power factor test, better known as the ”Doble
Test”, is a complete overall test of the insulating
properties of a transformer. Elements such as carbonization,
ionization, moisture, and heat can breakdown the
insulation's strength. The Doble test measures the power
losses due to leakage current through the insulation.

Question { 4727 }

what is the basic differnce between ground and earth

Answer

As mentioned earth and ground are the same terms used in
different countries. The earth (ground) conductor is
electrically connected to the earth so that anything it is
connected to, cannot become live. There will be be some kind
of local regulation determining the maximum resistance that
is allowed where the connection is made to ground (rod, mat etc)

The neutral is one connection of the supply transformer that
is also connected to earth. It is not a return path as such
because ac is changing direction. The reason it is connected
to earth is for safety. It means that a fault (to earth) of
the live conductor will cause the overcurrent device (fuse
or breaker) to operate and trip the power.

There are systems that do not connect one side of the supply
transformer to earth (no neutral). They still function just
the same as an earthed system. This is more common in
military or medical and requires some form of sensing
circuit to detect faults but the fault gives an alarm rather
than a trip so that power remains until an outage can be
planned to find the fault.

Question { Honeywell, 6412 }

why farmers are use earthing instead of neutral for their light conec. at
field.is it safe

Answer

As there is a vast difference between the Earth & Neutral
The ground or "earth" wire is a circuit's safety protective
wire that normally carries no current.

It is there to force a fuse to blow or a circuit breaker or
GFCI to trip if a fault condition occurs in any appliances,
their flexible cords or plugs that are connected into the
circuit.

By carrying away the excess current in a fault condition -
which should cause the protecting fuse to blow or circuit
breaker to trip - the "ground" or "earth" wire protects the
building and its occupants because the power should be cut
off before anyone gets electrocuted or any overloaded
circuit wiring or appliances catch on fire.

The neutral is the normal "return" wire: in systems where
the load is supplied from only one hot (or "live") wire, the
neutral completes the circuit and carries current back from
the load to the power station.

All the neutral and ground (or "earth") wires in a building
are tied or linked together at the incoming service main
breaker panel. This is the only place they should ever be
tied together because it is "upstream" of all the fuses
and/or circuit breakers protecting the hot (or "live") wires
for the various circuits installed in the building.

Warning: we must never assume that a neutral is safe to
touch: it has to be checked with a voltmeter or a voltage
indicator to be sure it is not "live". This is because a
neutral wire is designed to carry current under normal
circumstances.

So, if a neutral wire going back to the incoming main
breaker panel has not been properly connected - or suffers a
deliberate disconnection or some accidental damage which
causes it to break - then it and any neutral wires connected
to it further downstream will go live up to the break
because of being connected to the downstream loads which
still have hot feeds coming into them!

That is why we should never use a neutral as a substitute
for a proper, separate, ground or "earth" wire.

Question { 2911 }

what is diversity factor ? plzzzzzz describe me

Answer

Diversity factor: The probability that a particular piece of
equipment will come on at the time of the facility's peak
load. It is the ratio of the sum of the individual
non-coincident maximum demands of various subdivisions of
the system to the maximum demand of the complete system. The
diversity factor is always greater than 1. The (unofficial)
term diversity, as distinguished from diversity factor
refers to the percent of time available that a machine,
piece of equipment, or facility has its maximum or nominal
load or demand (a 70% diversity means that the device in
question operates at its nominal or maximum load level 70%
of the time that it is connected and turned on).

Diversity factor is commonly used for a number of
mathematics-related topics. One such instance is when
completing a coordination study for a system. This diversity
factor is used to estimate the load of a particular node in
the system.

Diversity Factor = Sum of Individual Max. Demand/

Max. Demand on Power Station

Question { Airtel, 5365 }

why we use perllel conection system in the wiring?

Answer

Possibly when any devices are connected in series wiring
connection if any fault happens in a device other devices
also gets effected, so in parallel wiring connection only
that device gets effected which have got fault.

Question { 3147 }

What are differences between Conventional & Addressable type
smoke detectors?

Answer

There are several differences between conventional &
addressable fire alarm systems. These differences include;
Addressable fire alarm systems give information about
individual detectors, whereas conventional systems only give
information
about specific circuits (zones).
1.
Due to this, addressable systems allow a courtesy text label
to allow easy identification of any event. For instance
detector 1
may be given the label “Bedroom 1
.
2.
Most addressable systems allow an early “pre-alarm” warning,
which allows the responsible person to investigate potential
alarms before the system activates it`s sirens
3.
Many addressable systems can alter the alarm threshold of
the detectors, in order to meet the needs of different
environments in
different areas of the system
4.
5. Addressable systems are usually wired in a loop.
Conventional systems are usually wired as radial circuits.
6. Addressable systems usually have a real time clock &
event log to record system events.
Larger addressable systems usually have the ability to use
sophisticated programming options to operate certain outputs
only
with specific events.
7.
Historically, addressable systems have tended to be
complicated to configure, and cost between 50% to 100% more
than a
conventional equivalent

Question { 2682 }

Can we provide 3phase wire in conduit for room?

Answer

No its not possible to provide 3phase wire in conduit for
room as per IS specifications.

Question { 3152 }

How can we save electrical cost i.e switchgear, wiring,
conduiting etc in a room?

Answer

By modification in electrical ckt.design.

Question { 3011 }

How many loops can be provided in a circuit as per IS rules.?

Answer

1-10 loops can be provided in a conduit as per IS rules for
a ckt.

Question { 9233 }

When we use PT in HT Panel why the ratio is 11Kv/√3/110v/√3
please explain briefly with suitable formula?

Answer

Potential transformers are instrument transformers. They
have a large number of primary turns and a few number of
secondary turns. It is used to control the large value of
voltage.


WORKING:
The potential transformer works along the same principle of
other transformers. It converts voltages from high to low.
It will take the thousands of volts behind power
transmission systems and step the voltage down to something
that meters can handle. These transformers work for single
and three phase systems, and are attached at a point where
it is convenient to measure the
voltage.e.g:11Kv/root3/110v/root3 for delta connection.