Briggs & Stratton PowerProtect 10kW with 200A ATS (040684) vs Briggs & Stratton PowerProtect 12kW (040666)
The Briggs & Stratton PowerProtect 12kW (040666) is the more powerful unit: 12,000 running watts against 10,000 — about 17% more capacity for the Briggs & Stratton PowerProtect 12kW (040666). The Briggs & Stratton PowerProtect 10kW with 200A ATS (040684) is the quieter of the two (67 dBA vs 70 dBA — though manufacturers measure noise at different loads and distances).
| Briggs & Stratton PowerProtect 10kW with 200A ATS (040684) | Briggs & Stratton PowerProtect 12kW (040666) | |
|---|---|---|
| Type | home-standby | home-standby |
| Fuel | natural-gas, propane | natural-gas, propane |
| Running watts (gas / LP for standby) | 10000 W | 12000 W |
| Running watts (propane) | 10000 W | 12000 W |
| Running watts (natural gas) | 8000 W | 10800 W |
| Noise level | 67 dBA | 70 dBA |
| Output voltage | 120/240V | 120/240V |
| Automatic transfer switch included | Yes | No |
| Main-line circuit breaker | 50 A | 60 A |
| Start type | automatic | automatic |
| Engine | Briggs & Stratton Vanguard M35 | Briggs & Stratton Vanguard M38 |
| Engine displacement | 570 cc | 623 cc |
| NG use at half load | 111 ft³/h | 117 ft³/h |
| Propane use at half load | 1.2 gal/h | 1.7 gal/h |
| Weight | 272 lb | 361 lb |
| Warranty | 6 yr | 6 yr |
Frequently asked questions
Which is more powerful, the Briggs & Stratton PowerProtect 10kW with 200A ATS (040684) or the Briggs & Stratton PowerProtect 12kW (040666)?
The Briggs & Stratton PowerProtect 12kW (040666), at 12,000 running watts on its best fuel versus 10,000 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 Briggs & Stratton PowerProtect 10kW with 200A ATS (040684) or the Briggs & Stratton PowerProtect 12kW (040666)?
Estimated fuel for 24 hours at about 50% load: $40 on natural gas for the Briggs & Stratton PowerProtect 10kW with 200A ATS (040684) vs $42 on natural gas for the Briggs & Stratton PowerProtect 12kW (040666), 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.