When relying on an oxygen concentrator, a power outage shifts from an inconvenience to an emergency requiring immediate action. Ensuring a continuous supply of medical oxygen depends entirely on having a reliable and correctly sized backup power source. Selecting the proper generator involves a precise calculation based on the machine’s electrical needs and the specific type of power it requires. Accurately matching the generator’s capacity and technology to the concentrator’s specifications is a fundamental step in emergency preparedness. This prevents an underpowered generator that fails to start the equipment or an incorrect power type that could damage sensitive internal components.
Determining the Oxygen Concentrator’s Power Draw
The first step in sizing a generator involves identifying the exact electrical requirements of the oxygen concentrator itself. Every electric motor, including the compressor in a concentrator, requires two distinct measurements: running wattage and starting wattage. The running wattage, also known as continuous wattage, indicates the power required to keep the device operating steadily once it is fully functional. Stationary home concentrators typically have a running wattage that falls between 300 and 600 watts, depending on the maximum oxygen flow rate they can deliver.
The starting wattage, or surge wattage, is a temporary, much higher burst of electricity needed to overcome mechanical inertia and start the compressor motor. This initial power spike can be significantly higher than the continuous operating load, sometimes two to three times the running wattage. Since the surge requirement is often omitted from labels, consult the user manual or manufacturer’s website for the precise surge rating. A generator must be capable of supplying this maximum surge power to successfully start the concentrator.
Higher flow settings require the compressor to work harder, which directly correlates to a higher running wattage. For example, a machine set to five liters per minute (LPM) will consume more power than the same machine set to two LPM. Portable oxygen concentrators, designed for mobility, draw substantially less power, often under 100 watts. Verifying the specific wattage on the device’s nameplate is the only way to get the foundational data needed for accurate generator sizing.
Calculating Your Total Emergency Wattage Needs
Accurately determining the necessary generator size requires accounting for all other essential devices needed during an outage. An emergency scenario demands power not just for the medical equipment, but also for minimal life-support functions and communication. A comprehensive calculation ensures that the generator can handle the full load without overloading or suffering a system shutdown.
The primary formula for generator sizing begins with the concentrator’s surge wattage, as this represents the highest single electrical demand the generator must meet. To this figure, you must add the running wattage of all other necessary appliances that will be operating simultaneously. These secondary loads might include a small refrigerator for medication storage, a phone charger for communication, and a single low-wattage lamp for visibility. Unlike the concentrator, these devices do not typically have a large surge requirement, so their continuous running wattage is used in the calculation.
The basic calculation is: (Concentrator Surge Watts) + (Running Watts of all other essential devices) = Minimum Required Generator Capacity. Once this minimum capacity is established, add a safety buffer of 10% to 20% to the final number. This margin prevents the generator from operating at its maximum capacity for extended periods, which helps maintain stable voltage and prolong the generator’s lifespan.
Choosing the Right Generator Technology
Once the total wattage requirement is calculated, selecting the correct generator technology is the next step, which is important for sensitive medical devices. Generators are separated into conventional and inverter models, distinguished by the type of power they produce. Conventional generators, often called open-frame models, produce AC power directly from the engine’s alternator, resulting in power with voltage fluctuations and a higher Total Harmonic Distortion (THD).
Inverter generators utilize advanced electronics to convert raw AC power into DC power, then “invert” it back to clean AC power. This two-step process results in an electrical output characterized by a pure sine wave, mimicking the quality of power supplied by the utility grid. This “clean power” is highly recommended for sensitive electronics like oxygen concentrators, as their sophisticated circuit boards can be damaged by the less stable output of a conventional generator. Inverter technology also allows the engine speed to adjust based on the load, making them significantly quieter and more fuel-efficient when running at partial capacity.
Regardless of the technology chosen, the physical placement and connection of the generator must adhere to strict safety standards due to the risk of carbon monoxide poisoning. Generators must be operated outdoors in a well-ventilated area, positioned at least 20 feet away from the home and any doors, windows, or vents. The power connection to the concentrator should be made using a heavy-duty, outdoor-rated extension cord plugged directly into the generator’s outlet. Avoid connecting a portable generator directly to a home’s electrical panel via a wall outlet, a dangerous practice known as back-feeding. The only safe way to connect a generator to a home’s wiring is through a properly installed manual transfer switch or interlock kit, which must be installed by a licensed electrician.