How do you work out Max Demand on a property

[blake floyds]

When filling in a Electrical insulation cert ,You have to work out the max demand I have read the on site guide but do not understand it to well has any one got any simple ways to do it or any where else I can look

 

[Taylortwocities]

Look up "Diversity" in the On Site Guide.

It does explain how you can work out estimated max demand.

Do note that the title of the book includes the word GUIDE

 

[Grinning Grandad]

I was told by my NIC assessor that to calculate Maximum Demand you simply total up the rated current of each protective device and the maximum demand is 40% of the total.

 

[FingRinal]

The OSG provides a good starting point at the design stage but is over the top for assessing in service max. demand.

The 40% 'rule of thumb' is a better guide for an in service domestic installation.

At the end of the day, there is no magic formula. For example, one large ring or two smaller rings both with the same overall total of sockets in the same locations for the same purposes - same demand or different?

If a property doesn't have 'wet' central heating, the chances are that the sockets will take a hammering from plug in electric heaters. Therefore it's not wise to apply the 40% rule of thumb if there is only one socket final circuit.