Result
Preliminary calculation: This tool is for quick sizing and information. Electrical installation designs and cable and protection selection must be done according to the relevant standards and by an licensed electrical engineer. Results are approximate.
Formula
S [kVA] = P_installed × k_div / cosφ × (1 + growth allowance)Because not all equipment runs at full load at the same time, a diversity factor is applied; the factor is set by facility type. A transformer is often selected to run at around 70-80% of the continuous load; this tool approximates that with diversity and growth allowance. For a generator, starting currents are the deciding factor.
- Chiller and compressor starts affect generator size
- A soft starter or inverter can reduce generator requirements
- Compensation reduces the apparent power requirement
Frequently asked questions
What is the diversity factor?
A coefficient reflecting the likelihood that all loads run at the same time; it is set by facility type and load profile.
Why can the generator come out larger than the transformer?
Motor starting draws a sudden load, so the generator voltage can drop; the starting load is therefore evaluated separately.
Will a project be approved with this value?
No. The electrical project must be prepared by a licensed engineer in accordance with the relevant regulations.