Indepth Electrical engineering

Bushings in Transmission Systems: Types, Classification & Applications Bushings are one of the most critical components in transmission and distribution systems . Their primary role is to provide insulation between energized conductors and grounded parts , ensuring safe current transfer through transformer tanks, circuit breakers, switchgear, and other high-voltage equipment. A failure in bushings can lead to catastrophic equipment damage, fire hazards, or extended outages. Hence, understanding their classification, design, and application is vital for electrical engineers and maintenance teams. Classification of Bushings Bushings can be classified into three main categories: 1.       Based on Insulating Material Used 2.       Based on Construction Type 3.       Based on Internal Insulation 1. Classification by Insulating Material Bushings are often categorized based on the type...

Electrical vehicles seems to becoming reality as there is increased focus on reducing pollution and reducing dependency on petroleum products. But there are many challenges while going with electric vehicles such as time required for charging the vehicles and space required for parking the vehicles and also higher cost of electric vehicles in comparison to other vehicles. There is also challenge for long driving as while driving long charging of vehicles will be required after few intervals, which required considerable time for charging again. There is lot of infrastructure and electricity is required to cater all these problems. Cost of driving electric vehicle is very low in comparison to petroleum products. There are few terms you must know before going through in details:- On Board Charging:- There are chargers which are factory fitted and are known as on board chargers and there are 2 types of charging devices for the same:- (i)       ...

Three-phase power — single-phase + three-phase loads explained (clean, compact & worked examples) Key rules  Power adds. Whether a load is single-phase or three-phase, its real power (kW) adds algebraically. A statement like “three-phase load = 90 kW” means total three-phase real power = 90 kW (i.e., 30 kW per phase in a balanced system), not 90 kW per phase. For balanced three-phase loads, you can convert total ↔ per-phase by dividing or multiplying by 3: P phase = P total / 3 P_{\text{phase}} = P_{\text{total}}/3 P total = 3 × P phase P_{\text{total}} = 3 \times P_{\text{phase}} Important formulas Total three-phase real power (line-to-line voltage) P 3φ    ( kW ) = 3    V L − L    I    P F 1000 P_{\text{3φ}}\;(\text{kW})=\dfrac{\sqrt{3}\;V_{L-L}\;I\;PF}{1000} where V L − L V_{L-L} is line-to-line RMS voltage, I I is line current (A), and P F PF is power factor. Total three-phase real power (line-to-neutral / per-phase voltage) P 3φ    ( kW...

National Electrical Code (NFPA 70) – Working Spaces for 600 V Electrical Equipment In electrical installations, providing adequate working space around electrical equipment is not just good engineering practice—it is a mandatory safety requirement under the National Electrical Code (NEC/NFPA 70) . These provisions are designed to ensure safe operation, inspection, and maintenance of equipment rated at 600 Volts, nominal, or less . This article explains the key working space requirements , exceptions, and clearances mandated by NEC for low-voltage electrical systems. 1. General Requirement for Working Space Sufficient access and working space must be provided for safe operation, inspection, and maintenance . Spaces must comply with NEC specifications regarding depth, width, and height . No storage or obstruction is allowed in the designated working space. 2. Working Space Depth Requirements (a) Minimum Depth The minimum clear working distance depends on system volt...

NFPA 70 (NEC) – Examination, Identification, Installation, and Use of Electrical Equipment The National Electrical Code (NEC), NFPA 70 , establishes mandatory rules to ensure the safe installation and use of electrical equipment. Below is a simplified breakdown of key requirements: 1. Examination of Electrical Equipment Before approving equipment for installation, the following must be checked: Suitability for purpose/environment/application (labeling, instructions, or listing). Mechanical strength and durability of enclosures. Adequate space for wire bending and connections. Electrical insulation integrity. Heating and arcing effects under normal and abnormal conditions. Classification by type, voltage, and current rating. Other safety factors relevant to user protection. 2. Installation and Use Equipment must be installed as per listing or labeling instructions . Voltage rating of equipment ≥ circuit’s nominal voltage. Conductor materia...

Savings by Using LED Lights: Cost, Payback, and Long-Term Benefits LED lighting has become one of the most effective ways to reduce electricity bills at home and in industries. While the upfront cost of LED lights is slightly higher compared to conventional tube lights, the annual savings, longer lifespan, and reduced maintenance costs make them a far superior choice. Let’s break down the numbers and see why LEDs are a smart investment. Conventional Tube Light vs LED Tube Light – Power Consumption 1. Conventional Tube Light (with choke) Tube Wattage: 36 W Choke Wattage: 36 W Total Consumption per Hour: 72 W (0.072 kWh) Daily Usage (10 hours): 720 Wh (0.72 kWh) Monthly Usage (30 days): 21.6 kWh Annual Usage: 262.8 kWh Electricity Tariff (avg.): ₹8 per unit Annual Cost: ₹2,102 2. LED Tube Light Wattage: 20 W Total Consumption per Hour: 20 W (0.02 kWh) Daily Usage (10 hours): 200 Wh (0.20 kWh) Monthly Usage (30 days): 6 kWh Annu...