A few other combination units, such as the Miller Electric Trailblazer, also incorporate independent weld/generator elements to provide clean power.

Fuel savings rank near the top of the list of requirements for many applications, and a combination welder/generator/compressor package may help. “For light-duty applications, it is a simple solution. For light or intermittent use, there can be a fuel savings, which of course saves you money and is better for the planet,” says Tod Gilbert, M.Sc, P.Eng, VMAC business transformation manager.

Maintenance and Reliability

Consider utilization of the various standalone components. “Fuel right now is as low quality as it has ever been,” says Leisner. “If it sits too long and separates, it can be harmful to your engine.” A combination unit will run the engine more consistently. It will therefore use up fuel faster than some individual units.

“In that same vein, you’re maintaining only one engine instead of two or three,” says Leisner. “In terms of scheduled maintenance and general upkeep, maintenance and repair is simplified because you’re only maintaining one machine. And you’re only dealing with depreciation on one machine.”

Reliability is also a consideration. “Most combination machines come standard with screw compressors, which produce 100% deliverable air all of the time, whereas you often have to stop and wait for reciprocating compressors to build up and kick in,” says Leisner. “Miller’s combination units are rated at 104° F, whereas many standalone units are only rated at 68° F. This higher rating means that you’re going to have greater performance and reliability regardless of your working conditions.”

Customers often have a misperception that combination units are more likely to overheat. “They actually cool more efficiently than standalone machines because there is an additional fan to pull air through the radiator for the compressor,” says Leisner. “It assists airflow through the machine rather than fighting it. Therefore, these machines tend to run slightly cooler.”

Vanair also dismisses concerns about excessive heat. “Some of our units are not enclosed in sheet metal and resemble more of a compressor design,” says Strathman. “This wide open design eliminates any concern of overheating. The enclosed combination units were designed with many features to prevent overheating. By utilizing remote engine oil coolers and 12-volt cooling fans, the units are rated for operation in ambient conditions up to 110° F.”

Realize potential limitations

There are limitations to combination units. This is especially true with the coming emissions regulations.

“Engines above a certain size are going to require a more advanced emission system, which is going to drive up cost,” says Gilbert. “If you are limited to engine size and splitting the power between multiple requirements, each one is going to be more limited. If you only really need one option, it is better to buy an individual product where all of the power available is dedicated to that feature.”

“The only real concern is the reduced horsepower,” agrees Strathman. “Combination units typically are sized to multifunction, but not at 100% capacity of all functions. Therefore, if you need to utilize the unit at 100% of multiple functions, you would be better off to stay with separate units.”

Building multiple functions into one machine also adds complexity to the design. “If there are more systems involved, there is potential for more to go wrong. The more complex units involve a greater understanding of all the systems for repair,” notes Gilbert. “Most systems are nicely designed with service and repair in mind. But again, if you don’t need an option, then there is no point in maintaining it.”

It is important to stick with the recommended preventive maintenance schedules. On the other hand, service is simplified. “Having the compressor, welder and generator in one self-contained unit actually makes repairs easier because there is only one service point for all three components,” says Worman.