Kubota GL11000 Lowboy II 11kW Diesel Generator (11000W, Receptacle)

The Kubota GL11000 is a Lowboy II liquid-cooled diesel generator rated 11 kW standby and 10 kW prime, built around Kubota's own Kubota D722 3-cylinder engine. Kubota builds the engine and the generator, which is the main reason these hold up in rental and contractor service where a machine gets used hard and maintained on a schedule rather than on inspection.

Features and benefits

• Kubota D722 diesel. 3-cylinder, liquid-cooled, with a 200-hour maintenance interval.
• Quiet for a diesel. 68 dB(A) at 23 ft, using a large-capacity radiator and muffler rather than just more insulation.
• Long run time. 7.39 gal tank gives 7 hours at full load, 12.7 hours at 25%.
• Single-side service. Routine maintenance items are reached from one access panel instead of walking around the machine.
• Protected automatically. Shutdown on high coolant temperature or low oil pressure, and double circuit protectors on the 120 V receptacles.
• Built to be moved. One-point lifting eye, 701 lb dry, 50.4 x 24.3 x 27.5 in.
• Output. 120/240 V single phase, 83.4 A at 120 V / 41.7 A at 240 V.

Receptacle model. Power is taken from outlets on the panel, which suits portable and jobsite use where the set moves between locations and gets plugged into cords. If it is going to be hard-wired to a building or a transfer switch, the -TM terminal-lug version is the one to order.

Altitude — read this before sizing

Kubota's own service guidance derates these naturally aspirated engines by about 1.5% for every 100 m (328 ft) of elevation, with losses beginning near 5,000 ft. Along the Front Range that is not a rounding error:

• Denver, ~5,280 ft: about 24% derate — roughly 8.3 kW available instead of 11 kW.
• Colorado Springs, ~6,035 ft: about 28% derate — roughly 8.0 kW available instead of 11 kW.
• Monument / Palmer Divide, ~7,000 ft: about 32% derate — roughly 7.5 kW available instead of 11 kW.

Add roughly 0.5% for every 5 °C above 25 °C on a hot afternoon, and Kubota recommends running at 80% of capacity for continuous duty. Rough idle, extra smoke or an unusual exhaust smell at elevation are normal responses to thin air rather than faults — and Kubota states plainly that modifications made to compensate are not warrantable and void the warranty. The answer is to size the machine for the elevation it will actually work at, not to adjust it afterwards. Tell us the site elevation and we will size against these numbers.