Introduction
Running refrigerators and freezers on inverters or uninterruptible power supply (UPS) systems can pose challenges due to high start-up currents, which are often overlooked. A typical refrigerator consumes about 100-150 watts of energy, leading many to believe that any inverter or UPS rated at 200-300 watts with a pure sine wave output would suffice. Unfortunately, this is not always the case.
The Problem with Start-up Currents
The primary issue is the compressor’s start-up current, which can surge to up to eight times the appliance’s regular power consumption. In addition, refrigerators require significant reactive power to keep the compressor running. This means that even though a unit may draw only 100 watts while operational, the power required to start it is much higher.
To guarantee that any standard household refrigerator starts up reliably, an inverter rated at 2,000 VA (approximately 1,400 watts) is recommended. Inverters rated at 1,500 VA (around 1,050 watts) will start approximately 80% of refrigerators, but some models may still struggle. Even certain inverter refrigerators—those that are more budget-friendly—can experience significant start-up current demands. If you’re interested in the details of choosing the right inverter type for your system, check out our Inverter Guide for more insights.
When selecting an inverter, it’s also crucial to consider inrush currents—the brief surge of power when an appliance starts up. For more information on this, read Accounting for Inrush Currents in Inverter Selection .
Managing Energy Use During Power Outages
For those relying on home backup power, energy conservation is crucial, especially when a refrigerator running at 100 watts could otherwise power a mobile phone several times or a laptop for up to three hours. This is why it’s important to plan ahead for power outages. Understanding idle power consumption can also be helpful when managing backup power systems—find more information in Idle Power Consumption in Inverters and UPS .
Cold storage batteries, also known as ice packs, are an affordable and effective solution. By keeping these batteries in your freezer, you can extend the cooling period during outages, often up to 12 hours. A proactive approach includes lowering the refrigerator’s temperature before a planned outage. Keep it cold enough to preserve food but avoid freezing items like vegetables. This ensures that when the power goes out, your food, medicine, and cold storage batteries are as chilled as possible, helping your refrigerator maintain low temperatures for up to 20 hours.
Solutions for Solar Systems
If your home is equipped with a solar power system, the situation is more straightforward. Solar systems with storage allow for continuous operation of essential appliances, including refrigerators, regardless of grid outages. The sun will rise again, recharging your batteries and continuing the cycle, ensuring uninterrupted power.
When building or upgrading a solar setup, consider how solar panels and inverters work together. Learn about the importance of the correct inverter choice for solar systems in Solar Panel Connections and Parameters . Additionally, if you’re still determining the appropriate number of solar panels needed to power your home, How Many Solar Panels for Home Heating provides practical insights for calculating your energy needs.
