Power Wiring Installations

Power Wiring Installations Points : power wiring installations, electrical power wiring installations

1. I.E.E. rules Nos. 22, 50, 51 are to be satisfied,
2. Wiring is to be installed either in surface conduits system or recessed conduit system.
3. Earth wire of 8 S.W.G. must run along the pipes.
4. Consumer must be provided two distinct earths in addition to the supplier’s earth. All the earths should be linked with each other.
5. Every switch board or control board of the machine or equipment must accompany with a suitable circuit breaker so that, if required, the supply must be terminated without any delay.
6. Controlling board should be placed as near as possible to the equipment.
7. For the selectioi1 of cable, the starting current of the equipment of motor is to be given due consideration.
8. The capacity of main switches or circuit breakers shall be of three times that of the normal current.
9. Efficiency, power factor are to be given due consideration. It can be assumed as 80% and 0.7 respectively unless otherwise stated.
10. Power Bushes (wooden or porcelain) are to be provided in all the metal frame of suitable design.
11. All the controlling switches in power wiring shall be mounted on the metal frame of suitable design.
12. When the outgoing lead is of U.G. Cable, allow a loop of 25 cm or the minimum bending radius above the switch. This is necessary the cable is not subjected to undue strain due to bending.
13. Avoid crossing in U.G. Cables within a shop.
14. In the case of the IJ.G. Cables, the size, the number of cores in the cable and the direction of flow of power, shall be clearly, marked within the point.
15. The layout of the 13.0. cable must he clearly marked with suitable indicators of G.I. or Aluminum boards indicating the location of the cable. It shall be of about 30 cm. This is sued in open ground and side of the streets.
16. Length of flexible metallic conduit shall not be greater than 2 mts.
17. Provision must be made for the emergency lights in the switch board room. This will until in illumination of the room whenever the supply fails.