Blue Star Power Systems · PSI Large Gaseous (265-500 kW)
Blue Star NG400-01
400 kW standby / 375 kW prime · Natural Gas / LPG · Liquid-cooled
400 kW natural gas / LP standby generator from Blue Star Power Systems. PSI 21.9L turbocharged V12, DSE DCP7310 controller, structural steel base, three-phase 208-600V.
The Blue Star NG400-01 is a 400-kilowatt natural gas / LP standby generator powered by the PSI 21.9L V12. It is rated 400 kWe standby / 375 kWe prime on natural gas (300 kWe standby on LP). The NG400-01 represents the transition to PSI's largest stationary gaseous engine platform, with a larger footprint, significantly higher heat rejection, and higher ambient tolerance than the 14.6L-based NG265–350 models.
The PSI 21.9L V12 is PSI's largest engine in Blue Star's stationary gaseous product line:
V12 configuration — 1,338 cu in (21.9L) displacement, 5.04-inch bore × 5.59-inch stroke, 10.5:1 compression ratio
684 bHp (510 kWm) at 1800 RPM standby
Extended ambient tolerance — full output to 97°F inlet air temperature (vs. 77°F on smaller models); deration altitude begins at 3,200 ft (vs. 1,200 ft)
Higher heat rejection — 1,760,700 BTU/hr to coolant; requires 39,995 CFM ventilation airflow for OPU installation
Deration: 1.5% per 10°F above 97°F inlet air temperature; 2.5% per 1,000 ft above 3,200 ft altitude.
The PSI 21.9L V12 is a significant step up in service complexity from the V8-based units. Two more cylinders means 4 additional spark plugs and ignition coils per service interval. The larger coolant system (51.0 gal total capacity) and oil system (10.6 gal) require more material per fluid exchange. Plan for the larger parts inventory and allow additional time per scheduled service relative to the 14.6L models.
Lock the enclosure, fuel system, transfer switch, and add-ons — we'll confirm pricing, availability, and lead time within one business day. Prefer a free-form quote? That option is still here.
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
4,200,000 BTU/hr≈ 4200.0 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 NG400-01 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
Turbocharger(s)
Significant power loss, heavy exhaust smoke
12,000+
severe
Ignition system (multi-cylinder)
Multiple misfires, output derating
1,500+
moderate
Charge air cooler
Reduced output, elevated intake temperatures
10,000+
moderate
Frequently Asked Questions
What is the standby rating of the NG400-01?
The Blue Star NG400-01 is rated 400 kWe standby on natural gas (300 kWe on LP) at 60 Hz / 1800 RPM. The PSI 21.9L V12 produces 684 bHp (510 kWm) at standby. The prime-rated variant is the NG400-01P at 375 kWe.
What engine powers the NG400-01?
The PSI 21.9L V12 — a 21.9-liter twelve-cylinder turbocharged-aftercooled spark-ignition engine (1,338 cu in, 5.04-inch bore x 5.59-inch stroke, 10.5:1 compression) rated 684 bHp (510 kWm) at 1800 RPM. This is PSI's largest engine in Blue Star's stationary gaseous lineup.
What are the deration factors for the NG400-01?
The NG400-01 has higher ambient temperature and altitude tolerance than the smaller NG models: derate 1.5% per 10°F above 97°F inlet air temperature (vs. 77°F for smaller models), and 2.5% per 1,000 ft above 3,200 ft altitude (vs. 1,200 ft for smaller models). The 21.9L V12 maintains full output to higher ambient conditions.
What alternators does the NG400-01 use?
For 208V and 240V three-phase, the Stamford HCI534C (WYE and DELTA respectively). For 480V three-phase, the Stamford S4L1D-F41. For 600V three-phase, the Stamford HCI534C. The HCI534C and S4L1D-F41 are the correct alternators for the 400 kW power level. All carry 125°C standby temperature rise and ±0.5% voltage regulation.
What are the dimensions of the NG400-01?
The OPU measures 156 x 86 x 98 in (L x W x H) and weighs 10,850 lbs — a step up from the 140 x 78 x 90 in OPU of the 14.6L-based models. Level 1 and 2 enclosures are 156 x 86 x 110 in (12,500 and 12,625 lbs). Level 3 sound-attenuated enclosure is 228 x 86 x 110 in at 13,325 lbs.
What are the ventilation requirements for the NG400-01?
A radiator-cooled OPU installation requires 39,995 CFM of ventilation airflow. Heat rejection to coolant is 1,760,700 BTU/hr and heat radiated to ambient is 495,060 BTU/hr — significantly higher than the 14.6L-based models. Confirm mechanical room ventilation capacity and exhaust duct sizing before installation.
Open Basler controller + PSI V12 engine + Stamford alternator — prime-rated, no proprietary lock-in. Serviceable by any qualified tech.
400 kW standby · Natural Gas / LPG · Liquid-cooled
375 kW prime natural gas for continuous-duty commercial, CHP, and campus applications needing 24/7 gas-fueled power.
375 kW prime-rated natural gas / LP generator from Blue Star Power Systems. PSI 21.9L V12, DSE DCP7310 controller, structural steel base, three-phase 208-600V.
Open Basler controller + PSI V12 engine + Stamford alternator — no proprietary lock-in. Non-proprietary components serviceable by any qualified tech.
425 kW standby · Natural Gas / LPG · Liquid-cooled
425 kW natural gas standby for large commercial, campus, and data center facilities where gas-fueled backup and component independence matter.
425 kW natural gas / LP standby generator from Blue Star Power Systems. PSI 21.9L V12 turbocharged-aftercooled, DSE DCP7310 controller, three-phase 208-600V.
Open Basler controller + PSI high-output engine + Stamford alternator — no proprietary lock-in. Serviceable by any qualified tech.
350 kW standby · Natural Gas · Liquid-cooled
350 kW natural gas standby for large commercial, campus, and data center facilities where gas-fueled backup and component independence matter.
350 kW natural gas standby generator from Blue Star Power Systems. PSI 14.6LHO high-output V8, DSE DCP7310 controller, structural steel base, three-phase 208-600V. Natural gas only — no LP rating.
