Luc De Vreese

ELECTRICAL THUMB RULE- Transformer: 1.    KVA = KW X 1.38 KVA = KW ( Power Factor X Efficiency ) KVA = KW ( 0.8 X 0.9) KVA = 1.38KW 2.    Current Rating of Transformer: KVA x 1.4 3.    Short Circuit Current Current Rating / % Impedance 4.    The diversity They would apply apartments is around 60% ( diversity Factor = sum of individual Demands / maximum Demands of the system) 5.    Maximum HT( 11KV) connected load will be around 4.5MVA Per circuit 6.    4 no’s Earth pit per Transformer ( 2 no’s For Body and 2 no’s for Neutral earthing ) Diesel Generator 1.    KVA = KW X 1.56 KVA = KW /( Power Factor X Efficiency ) KVA = KW ( 0.8 X 0.8) KVA = 1.56KW 2.    Diesel generator Set produces = 3.87 units KWH in 1 litre of Diesel 3.    Required area for the diesel generator 25 KW to 48 KW = 56 SQ meter, 100 KW= 65 sq metre 4.D G less than or equal to 1000KVA Should Place inside the Canopy UPS 1.    KVA = KW X 1.60 KVA = KW /( Power Factor X Efficiency ) KVA = KW ( 0.8 X 0.78) KVA = 1.60KW Cable current carrying capacity 1.    For Copper cable current carrying capacity ( upto 30Sqmm ) = 6 X Size of wire in Sqmm For Example, 2.5 Sqmm = 6 X 2.5 sqmm = 15 Amps Current Carrying Capacity of Equipment’s 1.    Single Phase motor Draws Power = 7 Amp / HP 2.    Three Phase Motor Draws power =1.25 per HP 3.    Full Load Current of 3 Phase Motor = HP x 1.5 4.    Full Load Current of 1 Phase Motor = HP x 6 5.    KW rating Of Motor  = HP x 0.75 6.    Full Load Current of equipment = 1.39X KVA ( for Three Phase 415 Volt) 7.    Full Load Current of equipment = 1.74X KW( for Three Phase 415 Volt) Earth Resistance: 1.    Earth Resistance for Single pit = 5 Ώ , Earth Grid = 0.5 Ώ 2.    As per NEC 1985, Earthing Resistance should be < 5 Ώ 3.    Voltage between neutral and earth < = 2 Volts 4.    Resistance between Neutral and earth < = 1 Ώ Minimum Bending Radius of cable 1.    Minimum Bending Radius for LT Power Cable = 12 X Dia of cable 2.    Minimum Bending Radius for HT Power Cable = 20 X Dia of cable 3.    Minimum Bending Radius for Control Cable    = 10 X Dia of cable

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How to draw 275kV Single Line Diagram ? The 275kV network is the backbone of Malaysia’s power grid, carrying bulk electricity across long distances before stepping it down into lower voltages. To truly understand how this backbone operates, you need to master the Single Line Diagram (SLD) — a simplified yet powerful way of representing the entire system in one drawing. In this video, I’ll walk you through how to draw a 275kV Single Line Diagram step by step. You’ll learn the standard symbols, the arrangement of critical equipment like circuit breakers, disconnectors, CTs, VTs, transformers, and busbars, and how they all connect in real-world substations. By the end, you’ll not only be able to sketch the SLD confidently but also appreciate how this diagram gives you a clear, bird’s-eye view of the entire backbone that keeps our lights on.

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⏭️ 1. Introduction ➡️ 2. Introduction to 📈 Transformers ➡️ 2.1 Principle of Operation.. ➡️ 2.2 Transformer Action. 💥 ➡️ 2.3 Transformer Voltage and Current. ➡️ 2.4 The Magnetic Circuit ➡️ 2.5 Core Losses 🤏 ➡️ 2.6 Copper Losses. ➡️ 2.7 Transformer Rating. 👈 ➡️ 2.8 Percent Impedance. ➡️ 2.9 Internal Forces . ➡️ 2.10 Autotransformers . ➡️ 2.11 Instrument Transformers. ➡️ 2.12 Potential Transformers. ➡️ 2.13 Current Transformers. ➡️ 2.14 Transformer Taps. ➡️ 2.15 Transformer Bushings. ➡️ 2.16 Transformer Polarity. ➡️ 2.17 Single-Phase Transformer Connections for Typical Service to Buildings. ➡️ 2.18 Parallel Operation of Single-Phase Transformers for Additional Capacity.. 2.19 Three-Phase Transformer Connections. ➡️ 2.20 Wey and Delta Connections. ➡️ 2.21 Three-Phase Connections Using Single-Phase Transformers ➡️ 2.22 Paralleling Three-Phase Transformers. 2.23 Methods of Cooling . ➡️ 2.24 Oil-Filled – Self-Cooled Transformers. ➡️ 2.25 Forced-Air and Forced-Oil-Cooled TRANSFORMER 😊 #electrical #electricalenginnering #transformer #job #powersystem #substation #generation #transmission #distrubition #hvdc #Eelectricaljobs #electricaltransformer #electricalhiring #hiring #jobs #electricalstudents #important #construcation #powerdistrubition #manufacturing #smartgrid #energymangement #electricalsafety #2025jobs

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🔌 Understanding Distribution Transformers–Powering Our Everyday Lives ⚡ This illustration highlights the working of a Distribution Transformer, a critical component in our electrical distribution system. Its main function is to step down high voltage (11kV) from the primary network to a usable low voltage (400V/230V) for homes, shops, and industries. 🔧 Key Technical Highlights: High Voltage Input (11kV): • Connected through the top three insulators (R, Y, B phases). Transformer Core: •Transfers energy through magnetic induction between primary and secondary windings. Low Voltage Output (400V/230V): •Delivered to end users through the secondary network. Earth/Ground Connection: • Ensures safety and system stability.

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