When a power outage occurs, maintaining the operation of an oxygen concentrator is critical for health and safety. Choosing the correct generator size requires a methodical calculation to ensure the concentrator receives continuous and reliable power. This article provides a step-by-step guide to accurately determine the generator capacity needed, ensuring the unit can handle both the continuous power demand and the initial surge required by your medical equipment. The process involves understanding the device’s specific power demands, calculating the total load, and selecting a generator with the proper electrical output quality.
Understanding Concentrator Power Needs
Determining your oxygen concentrator’s power consumption is the first step in sizing a generator correctly. The power consumption of a stationary home concentrator typically falls within a range of 300 to 600 watts (W) for continuous operation. This running wattage is the baseline power the generator must supply constantly. The actual power draw is directly influenced by the oxygen flow setting; a higher liters per minute (LPM) setting will increase the required wattage.
A generator must also account for the brief but significant electrical spike that occurs when the concentrator’s internal compressor initially turns on. This momentary demand is known as the Starting Watts or surge wattage, and it is always higher than the continuous running wattage. For example, a concentrator running steadily at 350 watts might have a starting requirement that momentarily jumps to 800 watts. You can locate both the running and starting wattages, or the amperage and voltage needed to calculate the wattage (Watts = Amps x Volts), on the concentrator’s data label or in the owner’s manual.
Calculating Total Required Running and Starting Watts
The calculation for generator capacity must include the power needs of the oxygen concentrator alongside any other essential devices you plan to run simultaneously. This sizing process involves three distinct steps to ensure the generator is never overloaded. First, list the running watts for all items you intend to power, such as the concentrator, a refrigerator, and minimal emergency lighting. For example, a concentrator might require 350 running watts, a modern refrigerator 150 running watts, and a few LED lights 50 running watts, totaling 550 running watts.
The second step is to identify the single highest starting wattage among all your essential devices. While the concentrator has a surge, the refrigerator’s compressor often has a higher starting wattage, perhaps 600 watts for a modern unit. The total surge capacity the generator must handle is the sum of the total running watts of all other devices plus the highest single starting watt requirement. In this example, the total running load (550W) minus the refrigerator’s running load (150W) plus the refrigerator’s starting load (600W) equals a peak surge requirement of 1000 watts.
The final step is applying a safety buffer to the calculated total to prevent overloading and premature generator wear. It is recommended to add a 20% safety margin to the highest surge wattage requirement. If the highest calculated surge is 1000 watts, multiplying this by 1.2 yields a minimum required generator capacity of 1200 surge watts. Therefore, select a generator with a rated running wattage that exceeds your total running load (550W) and a maximum starting wattage that exceeds the buffered surge load (1200W).
Generator Features Essential for Sensitive Medical Equipment
The quantity of power a generator produces is only one part of the equation; the quality of the electricity is equally important when powering medical devices. Oxygen concentrators contain sensitive electronic components that rely on receiving “clean power,” which refers to electricity with a smooth, consistent waveform. The measure of power quality is known as Total Harmonic Distortion (THD), which quantifies the deviation of the power signal from a perfect sine wave.
Conventional portable generators typically produce power with a high THD, often ranging from 9% to 20%, which is considered “dirty” power. This erratic power quality can cause malfunctions, reduce the lifespan of the concentrator’s electronics, and potentially void the device’s warranty. Sensitive medical equipment requires a THD of less than 3% to operate safely and reliably.
For this reason, an inverter generator is the preferred choice for medical backup power. Inverter models condition the raw power they produce through a multi-step process, resulting in a pure sine wave output with a THD of 3% or less. While inverter generators are often more expensive per watt than conventional models, the investment ensures the long-term integrity and reliable function of the oxygen concentrator.
Safe Setup and Connection Protocols
Proper physical setup and connection are safety procedures when operating a generator, especially for life-sustaining equipment. The generator must always be placed outdoors, as its exhaust contains odorless, toxic carbon monoxide (CO) gas. Position the unit at least 20 feet away from the home, ensuring the engine exhaust is directed away from all doors, windows, and vents to prevent fumes from entering the living space.
A working, battery-operated carbon monoxide detector should be installed on every level of the home and near sleeping areas. For connecting the generator to the concentrator, use heavy-duty, outdoor-rated extension cords that are appropriately rated for the electrical load. The safest connection method is a professionally installed manual transfer switch or an interlock kit wired to your main electrical panel. This prevents the hazardous practice of “back-feeding,” which can electrocute utility workers attempting to restore power.