Essential Electrical Notes Every Electrical Engineer Should Save Correct sizing of protection devices and power components is one of the most important aspects of electrical system design. Oversizing increases cost, while under sizing can lead to overheating, nuisance tripping, equipment failure, and serious safety risks. This quick reference covers the basic sizing guidelines for capacitor bank components. 📌 Key Design Formulas 1. Capacitor Current (3-Phase) I = (kVAR × 1000) / (√3 × Voltage) This is the foundation for selecting all downstream components. 2. HRC Fuse Selection • Fuse Rating ≈ 1.6 × Capacitor Current ‣ Handles capacitor inrush current ‣ Protects against short circuits ‣ Use HRC fuses with high breaking capacity 3. MCCB Selection • MCCB Rating ≈ 1.25 × Capacitor Current ‣ Provides overload and short-circuit protection ‣ Choose suitable breaking capacity (Icu/Ics) ‣ Coordinate with upstream protection devices 4. Capacitor Duty Contactor Unlike standard contactors,...
HVAC Air Balancing (TAB) – The Key to HVAC Performance 🔷 A professional and detailed explanation of HVAC Air Balancing (TAB) — the cornerstone of efficient HVAC system performance, written for MEP engineers, commissioning teams, and facility managers: 🌬️ HVAC Air Balancing (TAB) – The Key to HVAC Performance 🔹 Overview Testing, Adjusting, and Balancing (TAB) is the process of verifying and fine‑tuning an HVAC system to ensure that airflow rates, pressures, and temperatures meet design specifications. Proper air balancing guarantees thermal comfort, energy efficiency, and equipment longevity . 🔹 Purpose of Air Balancing Achieve uniform temperature distribution across zones. Maintain design airflow rates at diffusers and grilles. Ensure positive or negative pressure in critical areas (e.g., operating rooms, labs). Optimize fan and pump performance for energy savings. Validate system commissioning and compliance with ASHRAE standards. 🔹 TAB Workflow Pre‑Testing: Review d...