Question { CB&I Lummus, 50384 }

what is differance between dirty earthing and clean
earthing and their applications

Answer

Basically earthing is of two types treated and untreated.In
case of untreated the electrode is not provided with any
external charcoal water mixture it is also called as dirty
earth.Where as in case of treated we provide water charcoal
powder mixture externally and in that case it is called
clean earth.Resistivity of treated electrode is lesser than
untreated one.so for equipment and safety earthing we go
for treated electrode.

Question { Electrotherm, 24565 }

what is the difference between AC choke (inductor) and DC
choke (inductor), working and design point of view?

Answer

choke:

A power-supply filter whose inductance is used to limit the
flow of AC while allowing the flow of DC. Chokes naturally
maintain a more constant flow of current. Output voltages
do not rise as high as they would without this inductor in
the circuit; neither does it drop as low when compared to a
capacitor input filter circuit. Chokes hold the variation
of output voltage (ripple) to a relatively small value.

TOP OF PAGE

coil:

A number of turns of insulated wire wound around a form of
insulating material which may or may not include an iron
core. Some coils are rigid enough to be self-supporting and
do not require a winding form and/or a core to secure it. A
coil is also known as an inductor. Inductors possess the
property of having considerable opposition to the flow of
AC while allowing DC to pass through the flow.

There is nothing like AC or DC chokes.

Question { Hyundai, 11067 }

what is the difference between ELCB and RCCB

Answer

Both are same thing Only difference is that RCCb is
technical name and ELCB is commercial name.RCCB is residual
current circuit breaker which works on principle of residual
current and ELCB is earth leakage circuit breaker which also
works on principle of residual current.

Question { 17628 }

What is diference between ELCB & ELMCB?Also how its
application for use in design area?

Answer

ELCB belongs to the class of RCCB and ELMCB belongs to the
class of RCBO that is residual overcuurent breaker.Hence MCB
can provide earth leakage as well as overcurrent protection
whereas ELCB can only provide earth leakage protection.

Question { 5290 }

Can 60 Hz transformer be used inplace of 50 hz transfromer?

Answer

Transformers 1 KVA and larger, rated at 60 Hz, should not be
used on 50 Hz service
due to higher losses and resultant heat rise. However, any
50 Hz transformer will
operate on 60 Hz service.
A 60 Hz design is physically smaller than a 50 Hz design. DO
NOT use 60 Hz rated
transformers on 50 Hz service. Without special designs,
higher losses and greater heat
rise will result. Operating 60 Hz transformers at higher
frequencies may simply provide
less voltage regulation.