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.
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.
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.
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.
Tell us about the application — kW, voltage, application, install timeline — and we'll respond within one business day with budgetary pricing, lead time, and any sizing notes.
Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.
Estimate runtime on this tank
Fuel demand at 75% load
420,000 BTU/hr≈ 420.0 cf/min @ 1,000 BTU/cf
On utility natural gas the runtime is generally unlimited provided the supply line and meter can deliver this BTU/hr at the engine's required inlet pressure (typically 5–14" WC residential, up to 5 psi commercial). Confirm against the OEM's published fuel-pressure spec.
Service intervals
Manufacturer-recommended intervals for the Blue Star PS40-01 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 250 hours or 12 months
Coolant change
Every 4000 hours
Air filter
Every 1000 hours
Spark plugs
Every 1500 hours
Major overhaul
≈ 15,000 hours
Load bank test
Every 12 months
Common failure modes
What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.
Component
Symptom
Typical hours
Severity
Spark plugs / ignition
Misfire under load, hard starting
1,500+
minor
Battery
Failed to start during outage
8,760+
minor
Coolant system
Overtemp, coolant loss
6,000+
minor
Frequently Asked Questions
What engine does the PS40-01 use?
The PSI 4.3L — a six-cylinder V6 naturally aspirated engine from Power Solutions International, displacing 262 cubic inches (4.30 liters). At 1800 RPM, it produces 82.2 hp (61.3 kWm) standby. The 4.3L V6 is a mid-range naturally aspirated platform well suited to the 40 kWe standby output class. Both natural gas and LP outputs are equal at 40 kWe across all voltage configurations. Required fuel pressure is 11.0 in. W.C. from a 1.0-inch NPT connection. Deration applies at 1% per 10°F above 77°F inlet air and 3% per 1,000 ft above 1,200 ft elevation.
What is the difference between the PS40-01 and the PS40-01P?
The PS40-01 is a standby-rated unit at 40 kWe with a 2-year / 2,000-hour standby warranty and 125°C temperature rise. The PS40-01P is the prime-rated companion at 35 kWe continuous variable load with a 1-year / 1,500-hour prime warranty and 105°C temperature rise — a lower rise reflecting the continuous duty thermal requirement. The PS40-01P also includes a catalyst/silencer in place of the standard critical-grade silencer, and uses a wider OPU footprint (80 × 42 vs. 80 × 38 in) to accommodate the catalytic aftertreatment. Both use the same PSI 4.3L V6 engine and UCI224C alternator. Specify the PS40-01 for emergency standby and the PS40-01P for prime or continuous-duty applications.
How does the PS40-01 compare to the GM50-03?
The PS40-01 (PSI 4.3L V6, 40 kWe, 80 × 38 × 50 in, 1,575 lbs) and GM50-03 (PSI 5.7L V8, 50 kWe, 80 × 38 × 52 in, 1,800 lbs) share the same 80 × 38 in length/width footprint. The GM50-03 gains 10 kWe from a larger V8 engine at 225 lbs more weight and 2 inches of additional height. For installations where 40 kWe satisfies the load, the PS40-01 is the lighter and lower-fuel-consumption choice (628 vs. 736 ft³/hr NG at full load). Both derate at the same temperature and altitude thresholds (77°F / 1,200 ft).
What are the fuel consumption rates for the PS40-01?
At 100% standby load, the PS40-01 consumes 628 ft³/hr of natural gas or 251 ft³/hr of LP. At 75% load: 505 ft³/hr NG or 202 ft³/hr LP. At 50% load: 389 ft³/hr NG or 155 ft³/hr LP. Required inlet pressure is 11.0 in. W.C. at a 1.0-inch NPT connection. Heat rejected to the coolant circuit at full load is 138,000 BTU/hr; heat radiated to the enclosure or room is 41,940 BTU/hr. Combustion air draw is 112 CFM; ventilation air requirement for a radiator-cooled installation is 5,157 CFM.
35 kW prime / 40 kW standby natural gas / LP generator from Blue Star Power Systems. PSI 4.3L six-cylinder V6 engine with catalyst/silencer, Stamford UCI224C alternator, DSE DCP7310 controller, 208-600V output.
55 kW prime / 60 kW standby natural gas / LP generator from Blue Star Power Systems. PSI 5.7L eight-cylinder V8 with catalyst/silencer, Stamford UCI224E alternator, DSE DCP7310 controller, 208-600V output.
