Maximum Demand Calculation [repack]

Designing a system tailored to its actual peak load prevents chronic overheating, extending the lifespan of switchgear and distribution boards. Key Terms and Concepts

Utilities do not charge for a lightning-fast surge (e.g., starting a 200kW motor for 2 seconds). Instead, they measure the sustained load over a sliding window. If your load peaks for 5 minutes and drops to zero, the 30-minute average will be modest. However, if you sustain high load for the entire window, your MD spikes.

MD is not the instantaneous peak (which may last milliseconds), but the sustained peak over a sliding window (e.g., 30 minutes). Utilities use MD to size transformers, cables, and to penalize industrial users for poor load factor. maximum demand calculation

Compile a comprehensive schedule of all connected equipment. Group these loads into distinct operational categories, as they exhibit drastically different usage patterns:

When a facility's demand spikes near its calculated maximum threshold, an intelligent controller commands an on-site battery bank to discharge, supplying the excess peak power locally. This effectively "shaves" the peak demand registered by the utility meter, lowering infrastructure requirements and reducing monthly utility demand charges. Designing a system tailored to its actual peak

: Avoids tripping main circuit breakers.

Where:

For commercial and industrial users, MD is a major cost driver. Most large power tariffs are two-part, charging for both the total energy used (kWh) and the peak demand (kW/kVA) during the month.

The sum of the continuous ratings (in Watts or Amperes) of all electrical apparatus connected to the system. B. Demand Factor (DF) If your load peaks for 5 minutes and

Where ≥ 1.