BUY New & Used Commercial Backup Generators 100kW-499kW GENERATORS FOR SALE

Industries That Use 100 kW to 499 kW Generators

Here a generator stops covering one system and starts covering an operation, whether that is a building through an outage or a jobsite from a trailer.

• Hospitals and clinics: 100 kW is a common minimum for small clinics covering critical circuits; mid-size medical buildings often land at 150 kW or above.
• Construction: Towables running several major pieces of equipment at once, then moving to the next job.
• Rental fleets: Trailer units from 110 kW to 375 kW for short-term and project work.
• Agriculture: Grain elevators and irrigation districts, where pumps and augers stack up at harvest. Many land near 300 kW.
• Hotels: 200 kW covers many mid-size properties; larger hotels and convention space push to 250 kW and up.
• Data rooms: Server rooms in commercial buildings, on an automatic transfer switch.
• Water treatment and airports: Infrastructure where downtime is a compliance issue, often specified around 400 kW.
• Manufacturing: Groups of motors, pumps, and fans, where an outage stops output.

For sector-by-sector sizing, see the industries served section.

100 kW to 499 kW Generators at a Glance

• Apparent power: 125 to 624 kVA at 0.8 power factor.
• Current: 150 A at 100 kW to 602 A at 400 kW at 480V. At 208V the same span runs 347 to 1,390 A.
• Diesel burn at full load: 7.4 gal/hr at 100 kW, 10.9 at 150 kW, and 28.6 at 400 kW on our chart.
• Towable weight: 8,424 lb wet for a Multiquip DCA125SSIU4F on its trailer to 22,130 lb with a full tank for a Cat XQ425.
• Two formats side by side: trailer-mounted diesels for jobsites and rental, and pad-mount diesel or natural gas standby sets for buildings.
• First decision: scope. Backing up critical circuits and backing up the whole facility produce very different numbers, and the crossover usually sits near 150 kW.

The Three Bands Between 100 kW and 499 kW

A 400 kW spread is too wide to shop as one size. A load total usually lands in one of these:

For one size at a time, go to our 100 kW, 125 kW, 150 kW, 175 kW, 200 kW, 250 kW, 300 kW, 350 kW, and 400 kW generator pages.

Towables and Pad-Mount Sets We’ve Listed From 100 kW to 499 kW

A sample of units that have come through our yard, by listed output:

Listings thin out as size climbs: most sit between 100 kW and 249 kW, led by a long run of 110 kW Multiquip and Airman towables, and only a handful sit above 375 kW. Natural gas appears only on stationary sets and one power module, never on a trailer.

Spec Sheets for Five Models Between 110 kW and 375 kW

Towable and stationary, diesel and gas, from manufacturer sheets:

Multiquip rates the DCA125SSIU4F at 100 kW prime and 110 kW standby, and we list it at the standby figure, which is why so many 110 kW units appear above. The Generac pair shows what fuel changes at the same rating: the diesel SD150 runs a 6.7 L engine and the gas SG150 a 14.2 L engine, both rated 150 kW standby and 135 kW prime.

How Much Diesel a 100 kW to 400 kW Set Burns

Rows inside this band from our diesel fuel consumption chart:

Spec sheets here track the chart within a gallon or two an hour. Cat lists 7.4 gal/hr at full load for the D100 GC, matching the 100 kW row; Generac lists 11.2 for the SD150 against 10.9; and mtu’s DS400 lists 26.9, under the chart’s 28.6.

At full load a 100 kW set burns about 178 gallons in 24 hours, a 150 kW set 262, and a 400 kW set 686. Pad-mount sub-base tanks are quoted in hours of runtime: Generac’s SD250 tanks run from 153 gallons (8 hours) to 1,325 gallons (71 hours) at standby load.

Amps at 208V, 480V, and 600V

Our generator amperage chart gives these three-phase figures at 0.8 power factor:

At 208V, current crosses 1,000 A by 300 kW, more than double the 480V figure. The transfer switch, conductors, and breaker follow that number. Towables carry their own main breaker, 600 A on Generac’s MDG150DF4 and 800 A on Atlas Copco’s QAS 250, so check it against the current at your voltage. Our power calculators turn a load list into a working figure.

Critical Circuits or the Whole Facility?

Below about 150 kW most buyers are backing up chosen circuits; at 150 kW and above, many are backing up the building.

Between 100 kW and 150 kW the question is usually whether the next size up is needed at all. Settle it with the facility’s own data: peak demand from a utility bill, the motors that start together, and growth planned within a few years. At 150 kW many facilities cross into keeping most of the building running, and by 175 kW the load list sorts into tiers: life-safety and process loads, comfort loads, and anything that can wait. Total each tier, then decide how many the generator carries.

Trailer or Pad: How the Format Changes Across the Band

Towables fit work that moves or ends; pad-mount sets fit a building that will need backup for decades.

Trailer weight climbs steeply. Multiquip’s DCA125SSIU4F weighs 8,424 lb wet on a double-axle trailer, Generac’s MDG150DF4 12,990 lb on two 8,000 lb axles, and Cat’s XQ425 22,130 lb with a full tank, at 283.7 x 102 x 126.1 inches. Match the tow vehicle and hitch to the wet weight of the exact unit, and check your state’s towing rules.

The towables on these sheets are Tier 4 Final and list 66 to 75 dB(A) at 23 ft. Stationary emergency sets such as Cat’s D300 GC and Kohler’s 350REOZJC are EPA Tier 3, with housing and sub-base tank priced as separate line items. Browse towables in trailer-mounted generators and permanent sets in industrial standby generators.

Diesel or Natural Gas at Mid-Size?

Diesel for anything that moves or must carry its own fuel; natural gas for building standby where the gas service can hold the pressure and flow the set needs.

The gas line becomes part of the project, and supply requirements vary by model: 7 to 11 in. water column on Generac’s SG150 and SG200, 11 to 15 in. on the SG250, 15 to 20 in. WC on the Cummins C300N6, and 1.25 to 1.5 psi at the base frame on Cat’s DG350. Flow climbs with size, from 1,280 scfh at full load on the SG100 to 4,620 scfh on the SG400. Generac calls for a supply line not shared with other appliances and a regulator rated for about 1.5 times maximum flow. Low pressure or flow can cause long cranking and a set that won’t carry full load.

Gas engines run larger for the same rating, 14.2 L on the SG200 against 8.7 L on the diesel SD200, and the SG130 and SG250 carry no prime rating. Diesel units are listed under industrial diesel generators and gas units under industrial natural gas generators.

Ratings, Hours, and Buying Used at This Size

Price a set on the rating that matches its duty, and judge a used unit by format as well as hours.

Caterpillar defines standby as typical use of 200 hours a year with a 500-hour annual maximum. Generac ties warranty to the rating on the SG400, 2 years on standby and 1 year on prime, and some prime ratings, such as the SD175’s 158 kW, aren’t offered in the U.S. In our listings, used stationary standby sets in this band carry 68 to 931 hours, while used towables commonly carry several thousand and the highest-hour 110 kW units more than 18,000. Compare used industrial generators against new industrial generators when a spec calls for a factory warranty or a current tier.

Paralleling Near the Top, and When to Rent

Around 350 kW, two smaller sets in parallel start to compete with one large one; below that, a single set is the norm.

Paralleling keeps power on when one unit is down, but the controls have to match: Kohler’s APM603 and Decision-Maker 6000 can run up to 8 generators on an isolated bus, but only with units on the same controller, and Cat’s XQ425 parallels with other EMCP 4.4 units. For a single project or a bridge to a permanent set, rent through Stag Power Rentals; when budget timing is the obstacle, see our generator financing options.

Too Small or Too Large for 100 kW to 499 kW?

A diesel set that idles far below its rating collects unburned fuel in the exhaust, so oversizing is not a free safety margin.

Under 100 kW, the smaller range costs less to buy and install; past 499 kW, step up rather than run a set at its limit. Every size we carry is on shop by kW.

Inspected, Load Tested, and Backed After the Sale

Each unit in this range passes a 22-point inspection and load bank testing before shipment, which matters most on high-hour towables, some past 10,000 hours. Turnkey Industries has bought and sold industrial generators for over a decade. New or used, every purchase includes our 30-day IronClad warranty, and our service and maintenance team handles industrial generator repair and emergency service once the set is running.

Ready to Buy a 100kW – 499kW Generator?

Tell us whether you’re backing up circuits or a whole building, what voltage you run, which fuel you have on site, and whether the unit moves, and we’ll narrow it to a band and a format. See our used industrial generators and new industrial generators, or contact us to work through the load list together.