Generator manufacturers are producing a wide variety of models for fire departments to choose from to outfit their apparatus, offering a wide range of kilowatt (kW) sizes and a selection of footprints. Fire Apparatus & Emergency Equipment talks with generator makers and examines the array of generators available, their attributes, and how they are being put to use on fire apparatus.
Paul Newton, marketing director for Harrison Hydra-Gen, notes his company makes multiple models of generators in different levels of functionality and sizes, from standard and modular systems to complete systems and retrofit systems. “What we do is a bit different within any given kilowatt because the real difference is in manipulating the air flow,” Newton points out. “Our models are the Stinger, Falcon, Stealth, and Vulcan, with 6-, 8-, and 10-kW models being the most popular ones used on fire apparatus.”
In today’s environment with 12-volt LED lights, a lot of departments have moved to the 6-kilowatt Stinger, Newton says. “It’s very compact and can be installed in a number of different ways, in an assortment of places,” he notes. “The Stinger also is available in 3.6- and 4.8-kilowatt models. This year, we’re introducing a Stinger 3-kilowatt model with a whole new frame in a slightly smaller size that helps bridge the gap between a traditional generator and an inverter.”
Newton says that Harrison Hydra-Gen has been seeing a trend toward using smaller hydraulic generators on fire apparatus. “We’re also doing a large number of retrofits for fire departments that bought a fire truck without a generator but want one now,” he observes.
Harrison Hydra-Gen’s other generator models include the Falcon in 6-, 8-, and 10-kW sizes; the Stealth in 6-, 8-, 10-, and 12-kW models; and the Vulcan, in 6-, 8-, and 10-kW sizes. But, Harrison Hydra-Gen doesn’t limit itself to only those sizes, Newton says, adding, “We will build generators of 15 and 20 kilowatts or greater depending on the need and the specific requirements of the fire department.”
1 Harrison Hydra-Gen makes the Stinger model generator in 3.6-, 4.8-, and 6-kW models. (Photos 1-2 courtesy of Harrison Hydra-Gen.)
2 Harrison Hydra-Gen is introducing its newest model Stinger generator in a compact 3.0-kW size.
Karl K. Wilson, North American sales manager for Cummins, says Cummins makes the Onan brand of power takeoff (PTO) generators for mobile applications, hydraulic generators, diesel-driven generators, and gasoline-driven generators that are used by fire and emergency medical services departments. “The most traditional generator you’ll find on fire apparatus is the hydraulic generator,” Wilson points out. “They have a very flexible design, can be installed in various places, and have the ability to be engaged and running when traveling on the road, unlike a PTO-driven generator. For fire apparatus, 8-kilowatt hydraulic generators seem to be the most popular size, although we make hydraulic generators in sizes from 6 kilowatts up to 25 kilowatts.”
In a PTO generator for mobile operations, Wilson notes that its advantage is that it is cheaper than hydraulic and also can drive a higher kW load. “Some PTO generators go up to 40 kilowatts and also come in different voltages and three-phase options,” he says. “You’ll see these larger generators on trucks that have very large compressors or very large electrical draw demands.”
3 Cummins Onan makes a variety of hydraulic generator models like this one in sizes from 6 to 10 kW. (Photos 3-4 courtesy of Cummins Onan.)
4 This Quiet Diesel hydraulic generator made by Cummins Onan comes in sizes of 10 and 12 kW.
The diesel-driven generators made by Cummins Onan are separate from a vehicle’s chassis and typically are found on rigs such as command vehicles, Wilson says. “They range in size from 5 kilowatts to 20 kilowatts, with 12 kilowatts being the sweet spot,” he says. “They are used to power all the air-conditioning, lighting, electronics, and everything else on the truck.” Gasoline-driven generators typically are air-cooled, Wilson says, as opposed to all Onan’s other generators, which are liquid cooled. “The gasoline-driven generators are smaller packages and usually used on brush trucks and ambulances where space is at more of a premium.”
SMART POWER SYSTEMS
Jay Farrell, director of sales for Smart Power Systems, says Smart Power makes three main series of generators: the HR, ER, and Liberator series as well as two others, the LR and LRT series, that are made specifically for Ford chassis to work off a 10-speed transmission. “Our HR series is specifically designed for mounting on the top of a truck and has a top exhaust where heat vents through a heat exchanger for optimum cooling efficiency,” Farrell says. “It’s 32 inches long, 13½ inches wide, and 17 inches tall and is our most popular model generator.” The HR is available in 6.2-, 8-, 10-, 15-, 20-, 25-, and 30-kilowatt versions.”
5 The Smart Power Systems messaging screen in its ECU system. (Photos 5-6 courtesy of Smart Power Systems.)
6 A Smart Power Systems 10-kW HR model generator is shown installed in a pumper’s dunnage area.
Smart Power’s ER series is a side exhaust model that is made in 6.2-, 8-, and 10-kW sizes. “The ER and all of our generator products feature an ECU (electronic control unit) that is able to communicate with multiplex screens on fire apparatus,” Farrell points out. “The smallest industry size of the ER series is designed to mount in the dunnage area or in a compartment and saves valuable space for other gear and equipment.” Smart Power’s Liberator series is available in 10-, 15-, 20-, and 25-kW electrical output and is integrated with a hydraulic extrication tool power system by XRT Power Systems that can handle up to three hydraulic rescue tools simultaneously.”
Smart Power’s LR series comes in 6.2- and 8-kW models for Ford F-250 through F-650 chassis, Farrell says, while its LRT models are available in 6.2-, 8-, 10-, and 15-kW versions for Ford F-250 through F-650 chassis.
XRT POWER SYSTEMS
Bob Hansen, marketing manager for XTR Power Systems, says his company teamed up with Smart Power Systems to provide the fire industry with a fully integrated hydraulic generator and hydraulic rescue tool system. “The combined system uses one PTO to simultaneously produce 15 kilowatts hydraulic power to make 10 kilowatts of AC power, plus hydraulic power to operate three rescue tools at full capacity independently of each other,” Hansen says. “The generator and rescue tools can be run at full load, at any rpm (revolutions per minute).”
ALAN M. PETRILLO is a Tucson, Arizona-based journalist, the author of three novels and five nonfiction books, and a member of the Fire Apparatus & Emergency Equipment Editorial Advisory Board. He served 22 years with the Verdoy (NY) Fire Department, including in the position of chief.