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Proud to share a practical overview of a single-pole distribution substation (11 kV / 0.4 kV) installation.This layout i...
22/12/2025

Proud to share a practical overview of a single-pole distribution substation (11 kV / 0.4 kV) installation.

This layout illustrates how compact substations are designed for reliable power distribution in both urban and rural networks. It highlights key components such as:

- Lightning arrester
- Gang operated isolator
- Fuse cut-out
- Disc and shackle insulators
- 25 kVA distribution transformer
- LT panel
- Earthing system
- Safe clearances as per standards

What is particularly interesting is the balance of safety, space optimization, and maintenance access on a single pole structure. Proper earthing, correct mounting heights, and clear phase arrangement are crucial in reducing faults and enhancing system reliability.

I am sharing this for fellow electrical engineering students and professionals who are learning about distribution systems and field-level installations. Practical drawings like this help bridge the gap between theory and real-world power networks.

🔌 Cable Testing – A Critical Step Before Energization. ⚡ Before any electrical cable is energized, it’s essential to ver...
22/12/2025

🔌 Cable Testing – A Critical Step Before Energization.

⚡ Before any electrical cable is energized, it’s essential to verify its integrity through proper testing. Each test serves a specific purpose:

1️⃣ Continuity Test – Ensures conductors are properly connected end-to-end with no internal breaks. Low DC voltage is used, and resistance should be nearly zero (≈ 0 Ω).

2️⃣ Insulation Resistance Test (Megger) – Measures the insulation quality between conductors or to ground using DC voltage (typically 500–1000V for LV, 5kV for MV). Acceptable results are usually ≥ 1 MΩ per kV of operating voltage.

3️⃣ High Voltage Test (Hipot Test) – Confirms the insulation can withstand high voltage stress. An AC/DC voltage of about 2.5 × operating voltage is applied for 1 minute to check for breakdown, as per IEC 60502-2 standards.

✅ Remember: The Megger test does not replace the continuity test — each has its own role in ensuring cable safety and reliability.

Testing = Safety. Safety = Reliability.


🔧 HVAC Basics Explained – Dampers, CFM Calculation & MEP Thumb Rules ❄️🏢‼️‼️✅✅👇🏼👇🏼⚙️⚙️This post summarizes some of the c...
22/12/2025

🔧 HVAC Basics Explained – Dampers, CFM Calculation & MEP Thumb Rules ❄️🏢‼️‼️✅✅👇🏼👇🏼⚙️⚙️
This post summarizes some of the core HVAC engineering concepts required for proper air distribution, system sizing, safety, and energy efficiency in residential and commercial buildings.

🔹 HVAC Dampers
HVAC dampers are mechanical devices installed in ducts to control, regulate, or isolate airflow. They help in airflow balancing, zoning, pressure control, and fire & smoke safety.

Common types include Volume Control Dampers (VCD), Motorized Dampers, Fire Dampers, Fire-Smoke Dampers, Backdraft Dampers, and Balancing Dampers.
Motorized dampers operate using On/Off, Floating, or Modulating (0–10V / 4–20mA) actuators integrated with BMS/BAS systems.

🔹 CFM (Cubic Feet per Minute) Calculation
CFM represents the quantity of air supplied to a space and can be calculated using different methods:
• Room-based method: Using room volume and air changes per hour (ACH)
• Duct velocity method: Area of duct × air velocity

• Tonnage method: 1 TR ≈ 400 CFM
Correct CFM ensures thermal comfort, indoor air quality, and system efficiency.
🔹 HVAC MEP Thumb Rules & Formulas
MEP thumb rules help engineers perform quick preliminary design calculations, such as:

• Heat load estimation (BTU/hr)
• Airflow calculation (CFM)
• Chilled water flow rate (GPM)
• Pipe sizing based on flow
• Chiller and cooling tower sizing
• Pump head and power calculation
Understanding and applying these fundamentals is essential for HVAC design, commissioning, troubleshooting, and energy-efficient operation of building systems.
















Electrical Control Panel Components
22/12/2025

Electrical Control Panel Components

The image shows the method to calculate the nominal current of a transformer according to its power (MVA) and voltage.Fo...
22/12/2025

The image shows the method to calculate the nominal current of a transformer according to its power (MVA) and voltage.
For the transformer 33/11 kV – 10 MVA, the current is obtained with the formula √3 × V × I = kVA, resulting in approximately 195 A on the 33 kV side.

In the transformer 11/0.415 kV – 630 kVA, the volts and currents of each phase were measured:

Vrn = 233 V, Ir = 400 A

Vyn = 229 V, Iy = 550 A

Vbn = 225 V, Ib = 620 A

The power per phase is calculated with P = V × I, obtaining:
Pr = 93.2 kVA, Py = 125.95 kVA, Pb = 139.50 kVA.
Total power = 358.65 kVA, which indicates a remarkable imbalance between phases.

Best Earthing Copper Vs Aluminium.
21/12/2025

Best Earthing Copper Vs Aluminium.


Motor Rating?
21/12/2025

Motor Rating?

Two Way Switch Wiring - Stair lights wiring.
21/12/2025

Two Way Switch Wiring - Stair lights wiring.

which metal is best for earthing
21/12/2025

which metal is best for earthing

VFD Wiring Masterclass: Unlock Precision Motor Control with Delta VFD-EL
21/12/2025

VFD Wiring Masterclass: Unlock Precision Motor Control with Delta VFD-EL

single line diagram of substation
21/12/2025

single line diagram of substation

Star OR Delta
21/12/2025

Star OR Delta

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