Overview#
The Blue Star PS40-01 is a 40-kilowatt natural gas and LP standby generator powered by the PSI 4.3L — a six-cylinder V6 naturally aspirated engine from Power Solutions International. It is rated at 40 kWe standby on both natural gas and LP across all voltage configurations, from 120/240V single-phase through 347/600V three-phase.
Blue Star Power Systems pairs the 4.3L engine with a Stamford UCI224C alternator and DSE DCP7310 controller on a formed steel base. The OPU footprint is 80 × 38 × 50 in at 1,575 lbs — the same length and width as the larger GM50-03. Level 1, 2, and 3 enclosures are available with sound levels from 76 dBA (OPU) down to 63 dBA (Level 3) at full load.
PSI 4.3L Platform at 40 kW#
The PSI 4.3L V6 runs at 9.8:1 compression ratio with equal NG and LP output — a useful characteristic for installations where fuel type may change or LP is used as backup to utility gas service. At 40 kWe, the 4.3L operates comfortably within its 82.2 hp (61.3 kWm) capacity. Fuel consumption at full load is 628 ft³/hr NG, rising to 773 ft³/hr on the companion GM60-02 that uses a larger engine calibration from the same block family.
PS40-01 vs PS40-01P: Standby vs Prime#
For applications requiring continuous variable-load operation (prime power), the companion PS40-01P is the correct selection at 35 kWe prime. The PS40-01 is a standby unit — rated for emergency use without a continuous duty limit but not certified for unlimited-hours prime operation. The PS40-01P includes a catalyst/silencer and runs at 105°C temperature rise vs. the PS40-01's 125°C standby temperature rise.
When to specify the PS40-01#
- 35–40 kW natural gas or LP standby at commercial, light industrial, school, or multi-family residential sites
- Sites derating from 40 kWe above 1,200 ft altitude or 77°F inlet air — calculate the derated output for the specific site conditions
- Applications requiring 208-600V single- or three-phase output across both fuel types without output reduction
- Installations where the 80 × 38 in OPU footprint is available and load growth beyond 40 kWe is not anticipated
Our service experience#
The PSI 4.3L V6 is a proven naturally aspirated platform. Natural gas supply pressure at the generator should be verified under full load — utility gas pressure often drops during peak demand periods. The 11.0 in. W.C. requirement at the fuel inlet means the regulator and supply line must be sized for the full 628 ft³/hr flow. Periodic spark plug inspection is essential on naturally aspirated gaseous engines; the 4.3L at 40 kWe is lightly loaded but fouled plugs remain the leading maintenance-related source of misfire codes. Annual load bank testing to full 40 kWe output is required to maintain warranty compliance under the 2-year / 2,000-hour standby warranty.
