Frequently Asked Questions

Portable generators are shipped without a battery, so you will need to supply it. See the spec sheet or manual. Most electric-start portables can also be started by a pull-cord recoil start.

Since generators of 45kW and below are only shipped set up for natural gas, a simple field conversion will be required to use propane. For most models, in the regulator replace the natural gas orifice with the supplied propane orifice, and close the regulator about a quarter turn.

Other generators are available in both this size range and up to 6 million watts. Please call us with your requirements.

Your electrician will tell you what voltage and phase is currently being supplied to your building. Normally you would use that voltage and phase, unless a reason exists to change the service (which can be expensive). These are the voltages and phases which we supply:

• 120/240Volt, single phase (written as 1ph)

• 120/208Volt, three phase (written as 3ph)

• 277/480Volt, three phase (written as 3ph)

• 120/240Volt, three phase (written as 3ph)

“kW” stands for kilowatts, or thousands of watts. A 35kW generator will power 35 thousand watts, for example.

1. Is natural gas available at your site? If so, it may be the cleanest, most dependable source of fuel you can use. You will not have to refill a tank.
2. If natural gas is not available, propane vapor is the next alternative to consider. The propane supplier should be able to answer your questions about availability in your area and how large a tank you should consider.
3. Diesel fuel requires a tank also, which is sold with the generator. The generator may sit on top of the tank. Diesel fuel is more polluting than natural gas or propane vapor. Diesel supply in a power outage could be a problem if the diesel supplier does not have power to refill his trucks.
4. Gasoline should be the fuel of last resort because of the dangers associated with keeping it, and the possibility that it will degrade over time.

Aluminum does not rust. Steel inevitably rusts; Generac Power Systems’ warranty for steel enclosures is one year.

The description of the generator contains the wattage, the engine size, the word “generator,” the fuel, the enclosure, the voltage, and the electrical phase:

20 kW 1.6L Generator – natural gas – steel enclosure – 120/208V 3ph

In this example, “1.6L” is the engine size.

Federal standards (Tier 1) for new off-road diesel engines were adopted in 1994 for engines above 37 kW (50 hp), to be phased in from 1996-2000.

Tier 2 standards were phased in from 2001-2006 and yet more stringent Tier 3 standards were phased in from 2006-2008 (applying to engines from 37 – 560 kW).

Tier 4 standards, were phased in from 2008-2015, and further reduced CO and NMHC + NOx and PM emissions for engines from 37 kW – 560 kW.