by Generac
Generac Guardian 20kW 3-Phase
20 kW standby generator
Key specifications
- Rated output, propane
- 20 kW
- Rated output, natural gas
- 17 kW
- Fuel
- Dual fuel (NG / LP)
- Phase
- Three-phase
- MSRP (starting)
- $6,239
- Dimensions
- 48 x 25 x 29 in
- Weight
- 466 lb
- Engine displacement
- 999 cc
- Sound, running (23 ft)
- 67 dB
- Sound, exercise (23 ft)
- 58 dB
- Warranty
- 5 years
Unverifiable specs are omitted, not estimated. See sources below for what we can defend.
Fuel use
| Fuel | Half load | Full load |
|---|---|---|
| Propane | 2.39 gal/hr | 3.56 gal/hr |
| Natural gas | 219 ft³/hr | 307 ft³/hr |
On propane, a 500-gallon tank filled to 80% holds about 400 gallons. That runs the Generac Guardian 20kW 3-Phase for about 167 hours (7.0 days) nonstop at half load, or about 112 hours (4.7 days) at full load. See how much propane a generator uses for other tank sizes.
On natural gas, the gas line and meter have to deliver the full-load figure, 307 ft³/hr, even if the generator rarely runs that hard. Installers size the pipe to it.
Sources
Every spec above traces back to one of these citations.
- Generac product page — Standby Generator 20kW 3-Phase WiFi Enabled (G0070770) · checked July 2026
- Generac spec sheet: 20 kW 3-phase Guardian (G007077) · checked September 2026
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