Use Of Diversity Factor

Diversity is the relationship between the rated full loads of the equipment downstream of a connection point, and the rated load of the connection point. To illustrate:

• The building at these co-ordinates is fitted with a 100A main supply fuse.
• The distribution board has 2no. 6A breakers, 1no. 20A breaker and 5no. 32A breakers, a total, potentially, of 192A.

Not all these rated loads are turned on at once. If they were, then the 100A supply fuse would rupture, as it cannot pass 192A. So the diversity factor of the distribution board can be said to be 192A/100A, or 1.92, or 52%.

The diversity factor for all other installations will be different, and would be based upon a local evaluation of the loads to be applied at different moments in time. Assuming it to be 1.0 may, on some occasions, result in a supply feeder and equipment rating that is rather larger than the local installation warrants, and an over-investment in cable and equipment to handle the rated load current. It is better to evaluate the pattern of usage of the loads and calculate an acceptable diversity factor for each particular case.

In the case of the example given above, achieving a diversity of 1.0 or 100% would require well over twice the cross-sectional area of copper cable to be installed in a deep trench underneath a field, the rebuild of a feeder cabinet to larger dimensions, more substantial overhead supply cables for a distance exceeding 2km northwards and a different tariff, where one pays rather more for a kWh than at present. The investment required to achieve 1.0 simply isn't justifiable in this particular case.

The principle can now be used to look at other installations and their diversity factors, perhaps?

I wouldn't advice applying diversity when selecting cable size to wire in a domestic oven. Come Christmas day with everything on full blast, melted cable may spoil the enjoyment.

from the above explanation can we said it utilisation factor also?

Diversity Factor = 1/Simultaneous Factor

Both are independent of utilisation factor.