The Generator EngineEncyclopedia

Generac SG500 vs PSI 22L HO

The Generac SG500 and PSI 22L HO are both natural gas generator engines in a similar power class. Both are rated at roughly 625 kVA. Displacement is 25.8 L versus 21.93 L. The table below compares their full specifications side by side.

SpecificationGenerac SG500PSI 22L HO
Headline rating625 kVA625 kVA
Standby (50 Hz)
Prime (50 Hz)
Standby (60 Hz)500 kWe500 kWe
Prime (60 Hz)455 kWe
Displacement25.8 L21.93 L
ConfigurationV12V12
Cylinders1212
Rated speed1,800 RPM1,800 RPM
FuelNatural GasNatural Gas
CoolingLiquid-CooledLiquid-Cooled
EmissionsUnregulatedU.S. EPA Stationary
Dry weight1650 kg
OriginUnited StatesUnited States

Choosing between Generac SG500 and PSI 22L HO

Use this comparison as an engineering shortlist, then confirm the complete generator package against load profile, voltage, 50/60 Hz frequency, duty class, emissions rules, cooling margin, altitude, ambient temperature, enclosure design, controller features, and alternator sizing.