Indepth Electrical engineering

We have often seen in our routine that 3rd pin of plug top has larger length and diameter then other pins there is technical reasons behind the see below we will clear the same. This is due to following reason:- Resistance = Resistivity X Length                           Area larger will the area of earthing contact lower will be the resistance. You can see from the image below that earth pin has larger area then other pins. There are following reasons which we will derive from the larger 3rd pin are:- 1. It will provide protection to both human being and appliance by ensuring that 1st earth get connected before any appliance get supply and during disconnection of appliance earth will remains connected until supply get disconnected. 2. Due to larger area of earthing pin resistance get lower which will divert all fault current to earth quickly before it get passed to other system and may cause a...

Current transformers are used for measurement of current in any circuit. It has same working principle of that transformer but only used for step down of current.  Current Transformer are used in measurement circuits , it is advisable to use CT instead of connection ammeter in the circuit as currents above 20A ammeter size becomes so large which is not feasible that is why current transformers are used.  Current transformer  primary has only one turn. Current transformer primary is not really a turn but just a conductor. The primary winding of Current Transformer has very few turns, while the secondary winding have a many turns depends upon how much the current must be stepped down. There is extra precaution required during connections of CT are that secondary of CT should never be kept open which otherwise leads to very high secondary voltages which ultimately leads to burning of CT or even explosion of CT. So such conditions should be avoided. Now ...

Whenever anyone going to Install an AC then first everyone planned power charges that they will have to pay after using AC. Actually it is correct that one ton of air-conditioning is equal to 12,000 btu/hr. However the other question trying to convert a one ton A/C unit into kw/hr consumed is very dependant on the make and model of the air-conditioner, as well as its EER (energy Efficiency Rate). These range from 6-14 EER. Standard average one ton A/C unit consumes 1.335 KW/hr.  #13650 btu= 4.0004205 kwh  According to that for 1 Ton Ac 12000=3.51685 kwh  And , for 2 Ton AC 24000 btu required , for 2 ton Ac ,  as per calculation 7.33706 kwh power required.  But in practical is not there.  As 2 Ton AC is taking max 14 to 15 Amp.Load.  KW= VI  = 15*220  =3.3 kwh So for 1 Ton AC Power Consumption stands at 1.7 KWH For 1.5 Ton AC Power consumption stands at 2.5 KWH Similarly for 2 Ton AC Power consumption will be 3.3 KWH.

Here’s a detailed breakdown of the required tests for 66 kV and 132 kV XLPE cables per IS 7098 (Part 3) (covering 66 kV up to and including 220 kV), with reference to IS 60840 equivalents where applicable: IS 7098 (Part 3): Tests for 66 kV & 132 kV XLPE Cables Based on the BIS Product Manual for IS 7098 (Pt 3) , the following tests are specified—applicable to each completed length of cable and per manufacturing batch/consignment ( BIS ): 📋 Test Checklist for 66 kV & 132 kV XLPE Power Cables Standards Referenced: IS 7098 (Part 3), IS 60840 / IEC 60840 1. Routine Tests (Every Delivered Cable Length) Test Sequence Acceptance Criteria Conductor resistance Pre-insulation ≤ values specified in IS 7098 (as per cross-section & temp. corrected to 20 °C) Partial Discharge (PD) test After manufacturing, before HV PD ≤ 5 pC at 1.5 × U₀ (U₀ = pha...

It has been often found that most of think that material used for earthing will reduce earthing resistance. It has been often misconception that copper earthing plate or rod will have lower earth pit resistance then GI earthing plate or rod. Lets clear this fundamental regarding as often falling in this trap will lead to higher investment on earthing by using copper as earthing material. If one considers a plate electrode, the approximate resistance to earth is: Resistance formula for Pipe earthing (R) = (100r/2πL) X loge (4L/d) ·           L= Length of Pipe/Rod in cm d=Diameter of Pipe/Rod in cm r = Resistivity of Soil Ohm-meter. Resistance formula for Plate earthing (R) = (r/A) X   under root(π/A). ·          r = Resistivity of Soil Ohm-meter. ·          A=Area of Earthing Plate m3. As can be seen ...

Difference Between Grounding and Earthing: Myths vs Standards Electrical safety often raises confusion between the terms grounding and earthing . Many people assume that grounding refers only to the connection of current-carrying conductors (like transformer or generator neutral) to earth, whereas earthing refers to the connection of non-current carrying metallic parts (like enclosures, motor frames, or panels). 👉 This distinction is actually a myth. According to recognized standards, both grounding and earthing mean the same thing . The confusion mainly arises from differences in terminology across countries. Grounding vs Earthing: Origin of the Terminology British English (UK, IEC, IS): Uses the word Earthing . American English (USA, IEEE, ANSI): Uses the word Grounding . So, it’s more a matter of language preference than technical difference. Standards and Definitions IS 3043:1987 (Code of Practice for Earthing) The term...

Misconceptions About Fault Current Direction in Electrical Systems In electrical engineering, there are widespread misconceptions regarding the direction of fault current . Many assume fault current simply flows from the source to the load , as in normal operation. However, this interpretation is misleading and can cause incorrect system protection design. Fault Current Flow – The Correct Understanding Under normal conditions, current flows from source → load . During a fault at the load end , the effective resistance/impedance at the fault point reduces drastically (almost to zero) . As a result, the fault current appears to “flow backwards”: the load-end protection sees the fault first and should trip before the transformer or upstream breaker. In reality, although current is still drawn from the source, the magnitude and point of detection of fault current is determined by the fault location . 👉 That is why modern electrical systems are designed to ensure prote...