Westinghouse iGen4500
3,700 running / 4,500 starting W. gasoline.
official manual lists 3700 running watts and 4500 peak watts
Amazon searchHome Depot searchUse the about 4,500 W inverter class as the starting estimate for Oxygen concentrator, Refrigerator.
Running 1,050 W + largest start delta 1,400 W = 2,450 W peak. Add 25% headroom: 3,063 W.
For life-critical equipment, follow the device maker's backup-power guidance.
Sizing estimate only - confirm with a licensed electrician; never backfeed a panel.
Loads used
| Load | Running W | Starting W | Note |
|---|---|---|---|
| Oxygen concentrator | 350 | 350 | typical small load; follow device maker backup-power guidance |
| Refrigerator | 700 | 2100 | estimated 3x motor start |
Models in this class
Champion 100302
3,500 running / 4,000 starting W. gasoline.
official manual lists model 100302 with 3500 running watts and 4000 starting watts
Amazon searchHome Depot searchGenerac GP3600
3,600 running / 4,500 starting W. gasoline.
official Generac page lists 3600 running watts and 4500 starting watts
Amazon searchHome Depot searchWhy the estimate can change
Use nameplate watts when available. Pumps, compressors, altitude, fuel type, and extension-cord voltage drop can all change the practical generator size.