Indepth Electrical engineering

During starting of Induction motor , motor draws very high current as power factor at the start is very low. Power factor is very low because the magnetizing component of current  is very high at starting. At Start Magnetizing component current is very high as it has to overcome the reluctance offered by air gap between stator and rotor. This leads to higher current withdrawal during starting. You can also say that angle between core-loss component and net current increases. As power factor is angle between core-loss component and net current, then there will be decrease in power factor. During starting Power factor starts from zero and keeps on increasing and will be maximum at full load current. Rated Power factor of motor will be achieved at Rated current of motor. Usually it is power factor at start is considered as 0.2. Motors usually have rated Power factor between 0.80 -0.90. Power factor varies as per load connected to the motor. Chart for the same ...

Variable Refrigerant Flow (VRF) Systems Variable refrigerant flow type Air conditioners also known as Variable Flow Volume i.e. VRV, Where variable refrigerant means the ability of the system to control the amount of refrigerant flowing to multiple evaporators i.e. indoor units. Actually VRV consists of multiple Indoor units and all are connected to one single outdoor unit. VRV also provide the individual settings of all Indoor units and it can handle both heating and cooling in different zones simultaneously. VRV were originally manufactured by Diakin, Japan. These are more widely used for Industrial applications where ducting isn’t possible.  There is one problem that Design of VRF systems is more complicated and requires additional work compared to designing a conventional direct expansion (DX) system. Let’s how VRV is different from other Air conditioning systems:- Split Air-conditioning Split type air conditioning you have often seen which consists of one i...

🏗 ️ Technical Specification of Aluminium Cables (IS 7098: Part 1 – 1988) When specifying aluminium cables, you will often come across codes like A2XWY . This code represents the construction, insulation, armouring, and sheath of the cable. 🔑 Cable Nomenclature Codes Code Meaning A Aluminium Conductor 2X XLPE (Cross-linked Polyethylene) Insulation Y PVC Outer Sheath W Steel Round Wire Armour F Steel Strip Armour WW Double Steel Round Wire Armour FF Double Steel Strip Armour Wa Non-Magnetic Round Wire Armour Fa Non-Magnetic Strip Armour AW Aluminium Wire Armour 👉 Example: A2XWY = Aluminium conductor + XLPE insulation + Steel round wire armour + PVC outer sheath. 📌 Note: For Copper Cables , no pref...

Diesel Generator Working Principle and Four-Stroke Diesel Engine Explained 🔹 Introduction A Diesel Generator (DG set) is a reliable source of electrical power that combines a diesel engine with an alternator to generate electricity. It is widely used as a backup power source during grid failures and as a prime mover in remote areas where electricity supply is unavailable. A DG set typically consists of: Diesel engine – acts as the prime mover. Alternator – converts mechanical energy into electrical energy. Fuel system – stores and supplies diesel. Cooling & exhaust system – prevents overheating and removes gases. Control panel – monitors and regulates operation. 🔹 Working Principle of a Diesel Engine The diesel engine in a generator works on the principle of compression ignition . Unlike petrol engines that use spark plugs, a diesel engine compresses air to very high pressure and temperature: Compression ratio : 14:1 to 25:1 Temperature ra...

Current Transformers (CTs): Types, Classifications, and Performance Current Transformers (CTs) and Potential/Voltage Transformers (PTs/VTs) are the backbone of electrical measurement and protection systems. They serve as the “ears and eyes” of the power system , feeding scaled-down signals of high currents and voltages to relays, meters, and control equipment. Without CTs and VTs, direct measurement of high values (like 100A current or 132 kV voltage) would be impractical and unsafe. This article explains why CTs are essential, their classification, performance parameters, and differences between Class T and Class C CTs —with formulas, comparisons, and practical notes for engineers. Why CTs and PTs are Needed Measurement Limitation: Directly connecting a 100A current to an ammeter would require a very large meter coil, which is impractical to install. CTs solve this by stepping down current (e.g., 100A → 5A). Relay Protection: Protection relays cannot handle high voltage...

FIXED CAPACITOR Fixed capacitor is the capacitor in which capacitor value remains fixed. In these capacitor capacitance cannot be adjusted. A fixed capacitor is classified according to the type of material used as its dielectric, such as paper, oil, mica, or electrolyte. These types of capacitors are discussed in earlier post. VARIABLE CAPACITOR As clear from its name variable capacitor is one where A variable capacitor is constructed in such manner that its value of capacitance can be varied. A variable capacitor is similar to motor having rotor & Stator. It consists of two sets of metal plates arranged so that the rotor plates move between the stator plates. Air acts as dielectric in these capacitors. As the position of the rotor is changed, the capacitance value is likewise changed. à This type of capacitor is used for tuning most radio receivers. Its physical appearance and its symbol are shown in figure below. ...