Electrical Studys

1. You need to know Ohm's law V=IR, current is proportional to the voltage applied.

2. Electric shock is caused by current and not voltage. 30mA of current is enough to cause ventricular fibrillation in your heart.

3. Megger  is the name of a company. (Many people term measuring of Insulation resistance as Megger)

4. 'Exd' type equipments (sometimes called explosion proof) do not prevent explosion. They just help to isolate an explosion in the interior of the equipment from spreading outside.

5. Test before Touch. This is a mantra that every electrical engineer should remember. You need to check that there is no voltage before touching any live part. It may have been fed from a different source.

6. Nowadays, domestic fan regulators do not work on potential divider concept and there is no power loss if you operate the fan at lower/higher speeds.

7. System earthing and body earthing are different.

8. All motors are treated in kW/MW, transformers in MVA/kVA and fuses in A.

9. 'k' in kW, kVA, kA, kV need to be in smaller case and not as in KW, KVA, KA, KV.

10. Incidents can happen anytime and one should wear appropriate safety gear before working on an electrical installation.

11. In electrical cables, size of the core determines the amount of current it can carry and the thickness of Insulation determines the voltage level it can work at.

12. Making capacity of a circuit breaker is approximately 2.5 times its breaking capacity.

13. In transformers, Dyn11 vector group will become Yd1 if you change its primary and secondary sides.

14. Neutral is solidly grounded in the 415V system at the user end to protect people from shock.

15. 230V, that we measure is the rms value and the actual peak AC voltage is √2 * 230V.

16. Every electrical engineer should know how to give basic first aid and CPR. CPR can bring a dead person to life.

17. Zero watt bulbs available in the market are not actually rated for zero watt. Their ratings vary from 5W to 20W.