Electrical Inspection & Testing Basics

 Electrical Inspection & Testing Basics 🔥 

As per Shri SKB Valli sir all Electrical inspection equipment must be listed and all time good condition with calibration certificates

Common Electrical Test Equipment – What to use, where, and why

Electrical testing verifies safety, performance, and reliability by comparing measured values against expected results—helping reduce defects, failures, and nonconformities.

1. Multimeter (VOM)

 • Use: Measures voltage, current, resistance

 • Range: mV to kV | µA to A

 • Where: Panels, motors, wiring, appliances

 • Detects: Open circuits, short circuits, wrong voltage

2. Megohmmeter (Megger)

 • Use: Insulation resistance testing

 • Range: 250V – 15kV

 • Where: Cables, transformers, switchgear, breakers

 • Detects: Moisture, insulation degradation

3. DLRO (Low Resistance Ohmmeter)

 • Use: Measures very low resistance

 • Range: µΩ to <1Ω (up to 100A)

 • Where: Busbars, joints, contacts, windings

 • Detects: Loose or high-resistance connections

4. Ground Resistance Tester

 • Use: Measures earth resistance

 • Range: mΩ to kΩ

 • Where: Substations, towers, buildings

 • Detects: Poor earthing, unsafe grounding

5. Power Recorder / Power Quality Analyzer

 • Use: Records voltage, current, power quality

 • Range: System dependent (LV to HV)

 • Where: Panels, feeders, substations

 • Detects: Sags, swells, harmonics, PF issues

6. Hipotential (Hi-Pot) Test Set – AC / DC / VLF

 • Use: Dielectric withstand testing

 • Range: 1kV – 100kV+

 • Where: HV equipment, cables, motors

 • Detects: Weak insulation, leakage paths

7. Power Factor Test Set

 • Use: AC insulation diagnostic

 • Range: Up to ~12kV

 • Where: Transformers, bushings, CT/PT

 • Detects: Moisture, contamination, internal partial discharge

8. Winding Resistance Test Set

 • Use: Measures winding resistance

 • Range: 1A – 50A

 • Where: Transformers, motors

 • Detects: Loose connections, winding faults

9. Transformer Turns Ratio (TTR) Tester

 • Use: Measures transformer winding ratio

 • Range: Excitation <100V

 • Where: Power & distribution transformers

 • Detects: Winding faults, wrong connections

10. High Current Test Set (Primary Injection)

 • Use: Tests breaker tripping under load

 • Range: 500A – 15,000A+

 • Where: Circuit breakers, protection systems

 • Detects: Incorrect trip timing, faulty protection

11. Secondary Injection Test Set / Relay Test Set

 • Use: Simulates fault conditions & tests relay logic

 • Range: Variable voltage, current, frequency

 • Where: Protection relays, IEDs, digital breakers

 • Detects: Incorrect settings, malfunctioning protection logic

🔧 Right test. Right equipment. Right decision.