How to identify Transformer rating without Name Plate details?

A Rudrendra

• Jul 15th, 2016

By using type of bushings used we can know the following details 1.Whether it is step up of step down transformer 2.Voltage rating of primary and secondary side By using type of cooling we can fi...

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Why the Substaions are labled as 11KV/33KV or 66/11KV etc instead of label with the POWER TRANSFORMERS Rating (In MVA/KVA)?

kannanvellai

 Profile Answers by kannanvellai Questions by kannanvellai

• Mar 31st, 2009

All electrical equipments operated depend on voltage.In substations we can get same ratio transformers with various power ratings.Ex:400/200KV with 800MVA 315 MVAPower rat...

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Why many people not connect the APFC/Capacitors in DG circuit?

shrinirmal

 Profile Answers by shrinirmal Questions by shrinirmal

• May 1st, 2009

When normal supply is 'On' that time APFC will be on, At that time it will consume current, for correcting P.F, in case of D.G will not run continously so avoid over load on D.G APFC panel not connected.

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The single phase induction motor starts with two phases(Using capacitor). Why can't the three phase induction motor starts with two phase?

jeet29

 Profile Answers by jeet29 Questions by jeet29

• Jun 8th, 2009

For the starting of a single phase motor we need two different fields and the resultant of both the fields works as the operating field revolving the motor in the direction of strong field (for more...

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Why We should use only Fuse units in APFC Panel circuit instead of ACB/MCCB/MCB?

bittu123

 Profile Answers by bittu123 Questions by bittu123

• Nov 8th, 2011

Automatic power factor correction panels will control the load power factor by sensing various available parameters like Current, Power Factor, and KVAR.... Since sensing units are already there whi...

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What is meant by Floting Earth? What will happen if we use regular earthing instead of floting earth and Where do we have to use only floting earth.

sn_rangari23

 Profile Answers by sn_rangari23 Questions by sn_rangari23

• Sep 28th, 2009

Floating Earth used in High Voltage equipment for high voltage Pit-Earth Test carried out for Transformer, Generator, Compressor, cables etc. for checking the condition?of moister & dryness of the cable.?

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How can we measure the DC current directly?

hightechnaveen

 Profile Answers by hightechnaveen Questions by hightechnaveen

• Aug 6th, 2009

By using ammeter we can measure DC current.

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What is the output power equation for the solar cell?

theo23

 Profile Answers by theo23 Questions by theo23

• Sep 9th, 2009

P=Current per unit area x EMF

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What is single and 2 pole circuit breaker?

OLIELCTRICAL

 Profile Answers by OLIELCTRICAL Questions by OLIELCTRICAL

• Aug 18th, 2009

Single pole only connect in phase incoming and out going line the load. Single pole holes top one & bottom one. max rating - 25 amps. Two pole?connect in phase & neutral. 2 holes top two & bottom two. max rating - 32. example mcb.

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List the basic ways of determining the voltage standing wave ratio in a transmission line.

naveed_ahmed

 Profile Answers by naveed_ahmed Questions by naveed_ahmed

• Jul 13th, 2009

VSWR is a ratio of? Vmax to Vmin or Imax by?Imin?which can be theoretically?determined by using smith chart or practically determined by using vswr meter.

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How can we control or deduct harmonics?

veerateja

 Profile Answers by veerateja Questions by veerateja

• Jun 18th, 2010

By improving the power factor by using capacitor or by synchronous condenser the harmonics can be reduced.If three phase is used the harmonics can heat the neutral wire ,so it is better to keep the diameter of neutral wire more than the other phases.

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What is the thumb rule for insulation value in bus bars, phase to phase and phase to earth for 11 & 33 kV system?

sinhasunilk

 Profile Answers by sinhasunilk Questions by sinhasunilk

• Jul 3rd, 2010

It should be at least KV+1 at 40 degree celcius.

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Why the roots of the network function are +ve?

deepanshu_jadon

 Profile Answers by deepanshu_jadon Questions by deepanshu_jadon

• Mar 10th, 2010

Roots of the network function should be negative for the stability of the function.For positive roots network function is unstable.

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What is the thumb rule for insulation value in bus bars, phase to phase and phase to earth for 11 & 33 KV system?

A Rudrendra

• Jul 15th, 2016

As per my knowledge there is no thumb rule but the minimum clearance between phase to phase & Ph to Earth in 33KV is 1.5 & 1Meters

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What is the value of insulation resistance between Neutral and earth of a 65 KVA Generator?

csbalu

 Profile Answers by csbalu Questions by csbalu

• Aug 29th, 2009

First of all let me clarify this,Insulation value does not depend on KVA rating of the Generator.It depends only on the rated voltage of the Generator.The insulation resistance is measured between the...

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When we apply the DC voltage thro' the digital Megger to test the IR value for cable/motor winding etc., we can see the digital display of the test equipment showing more than the applied voltage (for eg. if we select 500V dc, we can see 526V dc in the display) Why?

sinhasunilk

 Profile Answers by sinhasunilk Questions by sinhasunilk

• Jul 3rd, 2010

When we measure IR value, we measure resistance of insulation of the circuit either w.r.t earth or w.r.t. to other phase.The digital display is resistance between the ckt and earth, not the voltage. I...

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What is the Specific Gravity of Fully charged Lead Acid Batteries?

prabhat.gaurav

 Profile Answers by prabhat.gaurav Questions by prabhat.gaurav

• Dec 8th, 2009

For Fully charged bateery specific gravity is 1.265 and its specific gravity starts decreasing  with the discharging of battery. and for fully discharged it's spec. garvity  is around 1.120

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How much min BDV of oil in transformer is required when charged it first time in 11kv, 66kv and 132 kv of transformer?

A Rudrendra

• Jul 15th, 2016

It should be minimum 54KV

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A motor rated 230V, 50HZ taking 100KW no load amps, what happen if just frequency goes to 60Hz?

wasi223

 Profile Answers by wasi223 Questions by wasi223

• Sep 29th, 2009

Ns=120f/pIf frequency increase than RPM increases.

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How to calculate voltage drop in cables?

buntysurat

 Profile Answers by buntysurat Questions by buntysurat

• Oct 23rd, 2009

Each Cable is specified with their R & X values per Km or Mtrs. For calculating Voltage Drop across cable the effective impedance Z must be calculated for given length of cable as Z = Square Root ...

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