Cummins QuietConnect RS20AC 20kW with 200A ATS vs Generac Guardian 14kW (7224)
The Cummins QuietConnect RS20AC 20kW with 200A ATS is the more powerful unit: 20,000 running watts against 14,000 — about 30% more capacity for the Cummins QuietConnect RS20AC 20kW with 200A ATS.
| Cummins QuietConnect RS20AC 20kW with 200A ATS | Generac Guardian 14kW (7224) | |
|---|---|---|
| Type | home-standby | home-standby |
| Fuel | natural-gas, propane | natural-gas, propane |
| Running watts (gas / LP for standby) | 20000 W | 14000 W |
| Running watts (propane) | 20000 W | 14000 W |
| Running watts (natural gas) | 18000 W | 14000 W |
| Noise level | 65 dBA | 65 dBA |
| Output voltage | 120/240V | 120/240V |
| Automatic transfer switch included | Yes | No |
| Main-line circuit breaker | 100 A | 60 A |
| Start type | automatic | automatic |
| Engine | Cummins QSJ999G | Generac G-Force 800 |
| Engine displacement | 999 cc | 816 cc |
| NG use at half load | 172 ft³/h | 195 ft³/h |
| Propane use at half load | 1.81 gal/h | 1.81 gal/h |
| Weight | 596 lb | 385 lb |
| Warranty | 5 yr | 5 yr |
Frequently asked questions
Which is more powerful, the Cummins QuietConnect RS20AC 20kW with 200A ATS or the Generac Guardian 14kW (7224)?
The Cummins QuietConnect RS20AC 20kW with 200A ATS, at 20,000 running watts on its best fuel versus 14,000 W. Remember that dual-fuel and natural-gas ratings are lower than gasoline ratings — the comparison table shows the published per-fuel figures.
Which costs less to run, the Cummins QuietConnect RS20AC 20kW with 200A ATS or the Generac Guardian 14kW (7224)?
Estimated fuel for 24 hours at about 50% load: $62 on natural gas for the Cummins QuietConnect RS20AC 20kW with 200A ATS vs $70 on natural gas for the Generac Guardian 14kW (7224), at national average prices. These are spec-sheet-derived estimates — the assumptions are on the methodology page, and different fuels make this a cost comparison, not an efficiency ranking.
Where do these specifications come from?
Every record on BackupAtlas is hand-curated from manufacturer documentation and spec sheets, and each generator page links to its source document.