Demand Factor=Maximum DemandTotal Connected LoadDemand Factor equals the fraction with numerator Maximum Demand and denominator Total Connected Load end-fraction
Elias pointed to a specific formula on the screen: $$ \textDiversity Factor = \frac\textSum of Individual Maximum Demands\textMaximum Demand on the Station $$
[ MD = \left( \sum_i=1^n (Load_i \times Demand\ Factor_i) \right) \times Diversity\ Factor ]
If you want to calculate this for a specific project, let me know: Is the property ? What are the largest appliances or machines being used? maximum demand calculation
: The most accurate method for existing buildings. It involves using a recording device to track the highest sustained current draw, typically over a 30-minute window .
To ensure the installation remains resilient against future expansion, it is standard engineering practice to add a spare capacity margin—typically between —to the final calculated value before specifying service transformers, main switchboard busbars, and incoming service cables. 4. Practical Worked Example (Commercial Office Space)
Example: A 1-minute spike of 1,000 kW averaged over 15 minutes: [ \frac(1000\ kW \times 1\ min) + (100\ kW \times 14\ mins)15\ mins = \frac1000 + 140015 = \frac240015 = 160\ kW ] It involves using a recording device to track
Applying engineering justification based on known operational profiles, typically reserved for complex industrial plants with highly predictable, automated load sequences.
If all equipment operates simultaneously in the 15-min window, diversity = 1.0. However, if the welding machine runs only when conveyors idle? Then diversity = 0.9. Let's assume simultaneous peaks. Final MD = 109.15 kW
Properly sizing cables and circuit breakers prevents overheating, tripping, and fires. diversity = 1.0. However
The rise of distributed energy resources (DERs) has complexified traditional maximum demand calculations:
: Used for specialized installations with fluctuating or intermittent loads, where a competent engineer evaluates the equipment's duty cycle. Key Calculation "Features" & Rules
: Setting the maximum demand based on the physical rating of protective devices like circuit breakers. Step-by-Step Calculation Guide