Demand Factor

[JatTiw]

I am planning a system which will have redundent motors(Stand-by or spare for running motor). My question is how to calculate future demand shall be from this load. Shall I consider the future demand shall be only from running motors or shall consider the future demand shall be 80% of total connected load. I am feeling the future demand shall be 80% of total connected load as the stand-by motor can be started while the main motor is running. Also suggest me any rule governing this issue.

 

[jbartos]

Suggestion: It depends what is involved. In some cases, even 100% future demand may be correct. Also, the lower damand than 80% may be correct. If a more responsible demand number is required, then an appropriate load analysis should be performed.