Dual-fuel generators

Fuel capability and generator type

Dual-fuel describes an engine’s fuel capability. The generator can also be an inverter model or a conventional portable model. Similarly, a standby generator approved for natural gas or propane may be configured for one installed supply; that does not necessarily provide automatic backup fuel switching. [3]

Tri-fuel products support a third specified fuel, often natural gas in addition to gasoline and propane. A supported fuel must be listed by the manufacturer for the exact model. Similar-looking equipment or an aftermarket conversion does not establish the same approval, capacity, or operating procedure. [4]

Read each rating

Fuel-specific running capacity can differ even when the headline starting rating is the same. As a concrete manufacturer example, Champion’s model 201321 lists 3,650 running watts on gasoline and 3,285 on propane, with 4,500 starting watts on either fuel. These figures apply to that model. [1]

A load plan intended to work on either fuel must be checked on both ratings. Also review voltage, available connections, starting behavior, and site corrections. A higher gasoline rating cannot be treated as the available continuous capacity when the engine is operating on propane.

Supply and switching

Gasoline and propane create different storage and replenishment tasks. Gasoline use involves the model’s tank, approved fuel, and storage requirements. Propane use involves the approved supply equipment and adequate vapor delivery. Comparing runtime requires the specified fuel quantity and load; two advertised runtime figures may use different test conditions.

Switching procedures vary. Some manuals require the engine to stop before changing fuel, while other designs provide different controls. Do not infer an automatic changeover feature from the words dual-fuel. Check the model’s instructions before planning an outage around uninterrupted switching. [2] [3]

Both fuels produce engine exhaust, including carbon monoxide. Fuel choice does not make indoor or enclosed operation acceptable. The generator’s safety equipment complements the operating precautions and maintenance requirements in its manual. [1]