Oxygen Concentrator Wattage for Generator Sizing
About the Oxygen Concentrator
A home oxygen concentrator that extracts oxygen from ambient air and delivers it to patients requiring supplemental oxygen therapy. These devices use a compressor and molecular sieve beds, creating a starting surge when the compressor engages. For oxygen-dependent patients, a generator is a medical necessity during power outages. Many oxygen concentrator users also maintain a backup supply of portable oxygen tanks, but tanks have limited duration while a generator can power the concentrator indefinitely. Medical equipment should be prioritized in any generator sizing calculation.
Generator Sizing for a Oxygen Concentrator
Running a oxygen concentrator by itself requires a generator with at least 625 W of capacity (1 kW), which includes a 25% safety margin. However, you rarely run a single appliance on a generator. When combined with other appliances, the oxygen concentrator contributes 300 W to the continuous running load and adds a potential 200 W starting surge gap when its motor starts.
The oxygen concentrator is an inductive (motor-driven) load with a starting surge of 500 W, which is 1.7 times its running wattage. This starting surge occurs for a fraction of a second when the motor first engages and must overcome inertia to begin rotating. Your generator must be capable of delivering this peak wattage even though it only lasts briefly. If the oxygen concentrator has the largest starting surge gap of any appliance in your generator load, its surge gap of 200 W will be the primary driver of your peak demand calculation. Avoid starting the oxygen concentrator at the same time as other large motor loads to prevent generator overload.
To determine the total generator size you need, use our interactive calculator to combine the oxygen concentrator with your other appliances. The calculator automatically handles the starting surge calculation and applies the 25% safety margin to give you an accurate recommendation. Alternatively, browse the scenarios below to see common generator setups that include the oxygen concentrator.
Scenarios That Include Oxygen Concentrator
The following pre-calculated generator scenarios include the oxygen concentrator in their appliance list. Each scenario shows the total generator size needed for all appliances in the set, not just the oxygen concentrator alone. Click any scenario to see the full appliance breakdown.
| Scenario | Total Appliances | Running Watts | Recommended Size |
|---|---|---|---|
| Emergency Medical Equipment | 5 | 635 W | 2 kW |
Tips for Running a Oxygen Concentrator on a Generator
When running the oxygen concentrator on a generator, the most important consideration is the starting surge. Before starting the oxygen concentrator, check that no other large motor-driven appliances are starting simultaneously. Stagger your startups: let the oxygen concentrator reach steady-state operation (usually within 1-2 seconds) before starting the next motor load.
If the generator struggles to start the oxygen concentrator (indicated by the generator bogging down, lights dimming significantly, or the appliance failing to start), it likely means the generator's peak surge capacity is insufficient. Try reducing other loads before attempting to start the oxygen concentrator again. If the problem persists, you may need a larger generator with more surge capacity.
Modern inverter generators handle motor starting surges particularly well due to their electronic power management. If you are purchasing a new generator specifically for loads that include the oxygen concentrator, verify that the generator's peak (starting) wattage specification meets or exceeds the 500 W starting requirement plus the running wattage of all other connected appliances.
Oxygen Concentrator Wattage Compared to Similar Appliances
The following table compares the oxygen concentrator to other appliances in the medical equipment category. Understanding relative power requirements helps you make informed decisions about which appliances to prioritize on your generator and where you might find opportunities to reduce your total load.
| Appliance | Running Watts | Starting Watts |
|---|---|---|
| Oxygen Concentrator (this appliance) | 300 W | 500 W |
| CPAP Machine | 60 W | — |
| Nebulizer | 40 W | — |
| Medical/Insulin Refrigerator | 100 W | 300 W |
Frequently Asked Questions
How many watts does a oxygen concentrator use?
A oxygen concentrator uses approximately 300 watts of continuous (running) power during normal operation. It also requires 500 watts of starting (surge) power when the motor first turns on, which is 1.7 times the running wattage. This starting surge lasts only a fraction of a second but your generator must be capable of delivering it.
What size generator do I need to run a oxygen concentrator?
To run a oxygen concentrator by itself, you need a generator rated for at least 625 W (1 kW), which includes a 25% safety margin above the starting wattage of 500W. However, most people run additional appliances alongside the oxygen concentrator, so your actual generator needs will be higher. Use our calculator to add your other appliances and get a comprehensive recommendation.
Can I run a oxygen concentrator on an inverter generator?
Yes, a oxygen concentrator can run on an inverter generator as long as the generator's peak (starting) wattage capacity meets or exceeds 500 watts. Inverter generators handle motor starting surges well and provide clean power that is safe for the electronic controls found in many modern oxygen concentrator models. Verify the inverter generator's surge rating in the specifications.