Sunday, October 13, 2013

Multimeter, Earthing, Megger, Motors fundamentals

Lets continue with Fundamentals of Electrical Engineering:-

1. Whenever checking electricity supply in Industry then keep assured with Multimeter as sometimes line tester may get failed and will not function and also Line tester even starts glowing at 5 V only.

2. Megger should be used to check motor winding resistance, Insulation of motor Multimeter may not always gives correct data.

3. In an Industry grid should be formed for Earth pits. As in grid all earth pits resistance comes in parallel with each other which will ultimately resistance of grid. Whenever earth fault occurred then fault current will go through grid as Grid offers lesser resistance.

4. Separate grids should be formed for Electrical and Electronic pits.

5. Double earthing of electrical system is required where there was there phase system is used and single earthing is sufficient in case of single phase system.

6. Electricity is not flow of electrons it's the vibration of electrons.

7. 3-Phase Motor direction can be changed by interchanging two phases.

8. Capacitor banks supplies reactive power and it doesn't consumes active power.

9. Capacitor banks Rating is in KVAR i.e. Volatage X Current X Sine angle.

10. Earth pit tester is used for measurement of earth resistance.