Choosing a portable industrial generator is a matter of matching serious power output to the realities of a job site. You need to know whether the unit can handle the loads, how portable it really is, and whether the price and condition line up with your expectations. The CAT MG-4 diesel 3-phase trailer-mounted generator set is a high-output option that demands that kind of scrutiny.
Quick Verdict
The CAT MG-4 is a 100kW three-phase generator engineered for demanding applications. It is powered by a D333 diesel engine that shows 1,441 hours, produces 480V, and is mounted on a trailer with new tires. At $9,000, it lands in a specific spot: serious capacity at a price that undercuts new industrial units, but with the risk that comes with a used machine.
Who It Suits
This unit is a good match for anyone who needs a big three-phase supply on wheels. Common scenarios include construction sites with multiple 480V tools, temporary power for industrial equipment, agricultural operations, or event production that requires substantial capacity. The trailer mounting means you can move it from one location to another without separate hauling gear, and the two 50 hp motor starts indicate it can handle the inrush current of large motors.
What Stands Out
The most obvious strengths are the 100kW rated output (putting it in the 50,100-100,000 watt range), the 480V three-phase output, and the D333 Cat engine. The 1,441-hour engine is a concrete figure that gives a sense of the unit's history, and the new tires are a useful sign that the trailer was recently refreshed. The two 50 hp motor starts are a practical detail for anyone powering large motors on site.
Meaningful Trade-Offs
The biggest trade-off is that this is a used generator. The $9,000 price is listed as "or best offer," which gives negotiators room, but it also means you're taking on the condition of a machine that has already been in service. The 1,441 hours on the D333 engine is not high for a diesel of this class, but it's not new either. The 480V output is a specific fit; not every site can use it, so your equipment and infrastructure need to match that voltage.
Bottom Line
The CAT MG-4 diesel 3-phase trailer-mounted generator is a purpose-built industrial tool. It offers 100kW of three-phase power, 480V output, and enough motor-starting capability for two 50 hp motors, all on a trailer that rolls on new tires. The $9,000 price reflects a used unit with 1,441 engine hours. If that matches your power profile and budget, it's a serious contender.
CAT MG-4 Diesel 3-Phase Trailer Mounted Industrial Generator Set
At $9,000, you get 100kW of rated output, a D333 diesel with 1,441 hours, and a trailer with new tires. It earns its keep on job sites that need real three-phase power. The demanding side is the 480V output: it's powerful and specific, so your equipment and site infrastructure need to match that voltage.
