Buy New & Used industrial backup Generators 50 kW GENERATORS FOR SALE

50 kW Generators for Welders, Compressors, Fabrication Equipment, and More

A 50 kW generator handles serious equipment without needing to step up to a larger industrial class. It comfortably runs large pumps, air compressors, and welding machines — the kind of loads that show up on active construction sites where several trades are drawing power at once. At the upper end of its range, a 50 kW unit can also supply enough capacity to keep essential services running for a small facility or remote operation entirely off-grid.

Standby Duty at Small Facilities and Remote Sites

Not every backup power need is tied to a jobsite. Rural facilities, remote outposts, and small standalone buildings without reliable grid access often land on 50 kW because it’s the smallest size with enough headroom to run an entire small operation — lighting, HVAC, water systems, and basic equipment — off a single unit instead of piecing together several smaller generators. It’s a size that shows up as often in “always-on” remote power as it does in temporary jobsite use.

Peak Draw, Not Average: Sizing at 50 kW

Accurate sizing starts with identifying every electrical load that could run at the same time, not just the average draw. Starting wattage matters as much as running wattage — motor-driven equipment like welders and compressors pull a sharp surge the moment they kick on, and that surge is often what actually determines whether a generator can handle the job. From there, factor in duty cycle, expected runtime, and site conditions like altitude and ambient temperature, all of which affect real-world output.

What to Total Before You Buy

• Running wattage for every piece of equipment operating simultaneously
• Startup surge wattage for motor-driven loads (welders, compressors, pumps)
• Expected duty cycle — continuous operation vs. intermittent backup
• Environmental factors affecting output, like altitude and temperature

A list with many overlapping loads is easier to total in our power calculator, and our team can help when it gets tangled. For output amperage, our amperage chart lists a 50 kW generator (3 phase, 80% power factor, 62.5 kVA) at 173 A at 208V, 152 A at 240V, 76 A at 480V, 61 A at 600V, and 8.7 A at 4160V.

Tank Runtime on Diesel, Pipeline Flow on Gas: 50 kW

At 50 kW, choosing a fuel comes down to how long the set has to run between refills, or whether it should draw from a supply line with no refills at all.

• Diesel, carried on board: Our diesel fuel consumption chart lists 40 kW and 60 kW but not 50 kW. For 40 kW it shows 1.6 gal/hr at 1/4 load, 2.3 at 1/2, 3.2 at 3/4, and 4.0 at full; for 60 kW it shows 1.8, 2.9, 3.8, and 4.8 gal/hr. For runtime, look for the figure the maker prints rather than working one out. Generac’s MMG55FHDCAN6 lists a 106-gallon tank, 95 gallons of it usable, a maximum run time of 28.5 hours, and 3.6 gph at 100% prime load.
• Natural gas, piped in: With no tank to size, the gas service has to deliver the flow instead. The Cummins RS50 sheet, which covers model C50N6, lists 341.3, 481.6, 624.6, and 806.3 cubic feet per hour at 1/4, 1/2, 3/4, and full load, and a supply pressure between 6.0 and 14.0 inches of water column. Gas units fall outside what the diesel chart covers.

Two inventory pages split the stock by fuel: industrial diesel generators and industrial natural gas generators.

Base Tank Size and Trailer Load on a Mobile 50 kW Unit

Mobile sets in this class keep their diesel in a base tank, so the tank decides how long the unit runs on site and adds to what the trailer carries on the road. Generac’s Magnum MMG55FHDCAN6 prints these figures:

• Tank: 106 gallons, with 95 gallons usable.
• Printed maximum run time: 28.5 hours.
• Weight on the standard single-axle trailer: 3,050 lb dry and 3,770 lb operating.
• Running gear: one axle rated 5,000 lb, surge brakes, and a 2-inch ball hitch.
• Trailer-mounted size: 150 x 57 x 67 inches.

When two units list different runtimes, ask what load each figure assumes before comparing them. Current mobile units are under trailer-mounted generators.

Why Two 50 kW Generators Rarely Cost the Same

Several things move the price of a 50 kW set, and a few of them are printed on the spec sheet.

• The voltage behind the rating: On the MMG55FHDCAN6, 50 kW standby is the 600V figure. At 480V the same sheet lists 43 kW standby and 41 kW prime, and at 208V it lists 37 kW and 35 kW. Check the rating at the voltage you will run.
• Current draw: Cable, breaker, and transfer switch sizes all follow the output current, so a 208V site and a 480V site end up with different hardware. Our amperage chart and power calculators cover both voltages.
• Tank capacity: a bigger base tank or an added auxiliary tank raises the cost and stretches the time between refills.
• Fuel system: a diesel set with its own tank and a natural gas set such as the Cummins C50N6 are built differently, and the gas set also depends on a supply line sized for it.
• Age and use: compare new generators with used generators, and check the hour meter and service history on anything used.
• Transport: trucking or towing the unit to your site.

The 50 kW sets we list can be quoted when you contact us.

50 kW Between Light Commercial and Heavy Industrial

Choosing around 50 kW is a question of crews and tools. A single major tool or minimal backup coverage points to our 45 kW generator, several crews drawing power together point to our 65 kW generator, and operations heading toward continuous, high-capacity use should look at our 100 kW generators.

Technician Certification Before a 50 kW Unit Leaves

Choosing a 50 kW generator is easier when the seller has been doing this for ten years. Ours clears a 22-point inspection before it ships, whether new or used, then carries our 30-day IronClad warranty. Preventative care and repairs after installation are handled by our service and maintenance team. To talk through your site requirements, get in touch or review the full inventory.