Total facility electrical load in kilowatts that the generator system must serve. Sum all critical and optional standby loads. Typical: 100-500 kW small commercial, 500-2000 kW datacenter/hospital.

Generator redundancy scheme. N = single unit, no backup; N+1 = one spare unit (most common for critical facilities); 2N = fully duplicated capacity. If omitted, defaults to 'N+1'.

Generator power rating category per ISO 8528-1. 'standby' = limited hours/year, higher output; 'prime' = unlimited hours, typically 85-90% of standby rating. If omitted, defaults to 'standby'.

Site altitude above sea level in feet. Derating begins above 1000 ft per NEMA MG1, typically 3-3.5% per 1000 ft above that threshold. If omitted, defaults to 500 ft (no derating applied).

Maximum site ambient temperature in degrees Celsius. Standard rating is at 40 C; derating applies above 40 C, typically 3% per 10 C. Typical: 35-50 C for outdoor installations. If omitted, defaults to 40 C (no derating applied).

Average operating load as a percentage of rated capacity. Affects fuel consumption estimate. Typical: 70-80% for standby, 60-70% for prime. If omitted, defaults to 80%.

Required fuel autonomy in hours. Overridden by nfpa_class when set (Level 1 = 96 hr, Level 2 = 24 hr). Typical standby: 24-72 hr. If omitted, defaults to 48 hours.

NFPA 110 classification for emergency/standby systems. Level_1 requires 96-hour fuel supply; Level_2 requires 24-hour. If omitted, runtime_hours is used directly. Recommended: enables automatic NFPA-compliant fuel storage sizing.

Generator load power factor used to convert kW to kVA. Standard generator rating is 0.8 PF per ISO 8528. Typical: 0.8-0.85. If omitted, defaults to 0.8.

Largest motor starting kVA that must be supported during generator operation. Compared against the generator's available starting kVA (skVA) to verify adequacy. If omitted, motor starting check is skipped.