Blue Star Power Systems · Gaseous Product Line (PSI 21.9LHO)
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Blue Star NG500-02
500 kW standby · Natural Gas · Liquid-cooled
500 kW natural-gas-only standby generator from Blue Star Power Systems. PSI 21.9LHO high-output V12 turbocharged-aftercooled, DSE DCP7310 controller, three-phase 208-600V. LP not available.
The Blue Star NG500-02 is a 500-kilowatt natural-gas-only standby generator built on the PSI 21.9LHO high-output V12 platform. It is rated 500 kWe standby on natural gas at 60 Hz / 1800 RPM. LP fuel is not available on this model — the high-output engine tuning is incompatible with LP operation. Three-phase only (208V, 240V, 480V, 600V).
The NG500-02 is one of two 500 kW natural gas standby models in the Blue Star lineup. The other — the NG500-01 — uses the larger PSI 32L V12 and supports LP but in a 210×96 in OPU. The NG500-02 delivers 500 kWe in the smaller 156×86 in footprint at the cost of LP capability.
The PSI 21.9LHO is the high-output variant of the 21.9-liter V12:
764 bHp (570 kWm) at 1800 RPM standby — 80 bHp more than the standard 21.9L (684 bHp)
Same 21.9L displacement (1,336 cu in) — output increase comes from high-output turbocharging and NG-optimized fuel delivery
Natural gas only — LP operation not supported (same pattern as NG350-02 and the 14.6LHO)
Standard deration: 1.5% per 10°F above 77°F inlet air temperature; 2.5% per 1,000 ft above 1,200 ft altitude
NG500-02 vs. NG500-01: choosing between the platforms#
NG500-02 (21.9LHO)
NG500-01 (32L)
Standby output NG
500 kWe
500 kWe
LP available
No
Yes (400 kWe)
OPU dimensions
156×86×98 in
210×96×103 in
Dry weight
11,450 lbs
15,500 lbs
Deration base
77°F / 1,200 ft
97°F / 4,200 ft
NG consumption @ 100%
5,330 ft³/hr
5,878 ft³/hr
The NG500-02 is the right choice when the site has natural gas only, space is limited to the 156-in footprint, and deration thresholds are manageable. The NG500-01 is preferred when LP backup is required or deration tolerance at altitude/heat is a concern.
The PSI 21.9LHO is less common in service territories than the standard 21.9L, but parts cross-reference to the same PSI catalog. Higher standby output increases thermal loading on V12 ignition and fuel components — budget for more frequent spark plug service than a comparable standby-rated standard 21.9L.
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
5,250,000 BTU/hr≈ 5250.0 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 NG500-02 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
Why does the NG500-02 not support LP?
The NG500-02 uses the PSI 21.9LHO — a high-output variant of the 21.9L V12 tuned specifically for maximum natural gas output at 500 kWe. The LP fuel system is not compatible with the high-output tuning. The spec sheet explicitly lists LP consumption as N/A. If LP backup capability is required at 500 kW, specify the NG500-01 (PSI 32L, which supports LP at 400 kWe standby).
How does the NG500-02 differ from the NG500-01?
The NG500-02 uses the PSI 21.9LHO (high-output 21.9L V12, 764 bHp) in the same 156×86×98 in footprint as the NG400/425/450 family. The NG500-01 uses the PSI 32L V12 (966 bHp) in a larger 210×96×103 in OPU. For sites with tight space constraints, the NG500-02 delivers 500 kWe standby in the smaller chassis — at the cost of LP capability and with standard 77°F / 1,200 ft deration thresholds.
What is the PSI 21.9LHO?
The PSI 21.9LHO is the high-output variant of the 21.9-liter V12 spark-ignition engine, rated 764 bHp (570 kWm) at 1800 RPM standby — 80 bHp more than the standard 21.9L. The increased output is achieved through higher turbocharging and optimized fuel delivery tuned for natural gas only. Blue Star uses the same LHO designation convention as with the 14.6LHO used in the NG350-02.
Is the NG500-02 available in single-phase?
No. The NG500-02 is three-phase only in 208V, 240V, 480V, and 600V configurations.
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