Overview#
The Gillette SP-250 is a 25-kilowatt natural gas (also rated 25 kW on LPG) standby generator built for small commercial applications: restaurants, retail spaces, small offices, and light-duty commercial buildings that need reliable backup on piped natural gas. At 25 kW, it covers essential loads — refrigeration, lighting, POS systems, and HVAC controls — without the footprint or cost of a larger unit.
Like all Gillette SP Series units, the SP-250 uses industry-standard name-brand components: a PSI 2.4L inline-4 engine, Stamford alternator, and Deep Sea Electronics DSE 7420 MKII controller. Every unit is assembled and 100% load-tested at Gillette's factory in Elkhart, Indiana. For Northern California commercial customers who value non-proprietary parts and open-architecture service access, the SP-250 is a practical entry point into gaseous standby power.
The PSI engine platform#
The SP-250 is powered by PSI's 2.4-liter naturally aspirated inline-4 engine — a compact, purpose-built industrial gas engine with 143.5 cubic inches of displacement. This is not a converted automotive or diesel platform; PSI designs these engines specifically for stationary power generation on natural gas and LP fuel.
Key characteristics of the 2.4L platform include an electronic governor with isochronous frequency regulation (1/4% steady-state), electronic fuel injection for consistent air-fuel ratio across the load range, and catalytic converter compatibility for sites requiring additional emissions control. At 1800 RPM the engine produces 42 brake horsepower on natural gas — well-matched to the 25 kW generator rating with adequate reserve. At this power class, the PSI 2.4L competes against Generac's proprietary engine platforms, with the advantage of open-market parts availability.
Our service experience#
We service PSI engines across multiple generator brands in our territory, so the 2.4L platform is familiar territory for our technicians. The DSE 7420 MKII controller is the same platform we see on Gillette, Blue Star, and other commercial generator brands — no proprietary software or dealer-locked diagnostics required.
Parts availability in Northern California is straightforward: PSI and Stamford components are available through industrial distributors, and common consumables (spark plugs, oil filters, air filters) cross-reference to widely available part numbers. There is no local Gillette dealer in our area, so we recommend customers keep critical spares on-site — a set of spark plugs, oil filters, and a replacement battery. The 25 kW class is easy to support and the SP-250's open-component architecture means you are never locked into a single service provider.
