Continous, Intermittent and standby loads; Demand Factors?

[Wael]

In most oil and gas projects, loads are devided into continuous, intermittent and standby loads; are summed up separately and then applied with 1, 0.5, 0.1 diversity factors for continuous, intermittent and standby respectively. Then,

maximum running load = continuous loads*(1.0) + intermittent loads*(0.50)

Peak Load = continuous load*(1.0) + intermittent loads*(0.50) + standby loads*(0.10)

Are those applied diversity factors: 0.50(for intermittent), 0.10 (for standby) an industry practice? or is there a code that recommends these factors?

 

[BigBang]

Wael

There is no code that specify these values, and thus the method of specifying them is somewhat random, but based on case by case bases. These values are tailored to meet the "expected" load demand/time for commercial & industrial customers. Working for a utility, I would say 0.5 and 0.1 are typical values for industrial customers such as oil, gas, water pumping stations, etc. Keep in mind each customer will have a different load profile and these values may be adjusted accordingly. Also, since sizing transformers, cable/wire, etc is dependent on those values, an engineer would err on the side of caution and be somewhat conservative. Overloads of equipment for such customers cause heating, unacceptable voltage drop, etc. Given the importance of near-continuous service to those customers, specifying higher diversity factors is a norm.

Hope that helps