Introduction
Imagine you’ve just set up your inverter to power your appliances, only for the inverter to beep, indicating that it has detected an oversized load and is switching off to protect itself. You read the nameplate on your device. It says 350W. You read the one on the inverter. It says 500 W max. 350 is definitely a smaller number than 500, so what’s going on? The issue is a phenomenon called inrush current. In this guide, we’ll explore what inrush current is, which devices are prone to it, and why it’s essential to be mindful of it, when deciding what size inverter to buy and when deciding what devices to plug into it at any given moment.
Understanding Inrush Current
1. What is Inrush Current?
Inrush current is like a brief power hiccup that occurs when certain appliances are turned on. It’s a brief but large increase in electrical demand that happens in the immediate moments after certain types of devices are switched on. Think of it like opening a bottle of peanut butter. When it’s on tight, it takes a whole lot of effort to turn it. However, as soon as it has turned that tiny little bit, suddenly it’s super easy to open. In that same way, inrush causes a power demand which is much higher than the rated output of the device, but only when it’s switched on. Thereafter, it will operate within its normal rated demand.
2. Causes of Inrush Current
Devices with motors, compressors, or transformers exhibit inrush current. When these appliances start, they demand a momentary surge of power to get going, causing a spike in the electrical demand (2 to 5 times the rated power demand). When your home is powered by the grid, the effect of this surge is rarely noticeable (fluorescent lights may dim slightly, or make a slightly different buzzing sound).
What Appliances Cause Inrush Current?
1. Refrigerators:
Your trusty fridge is a prime candidate for inrush current. The compressor, responsible for cooling, requires a surge of power to get going. This surge is often substantially more than the refrigerator’s regular rated operating power.
2. Microwave Ovens:
Microwaves, especially high-powered models, can generate inrush current when initially switched on. The sudden demand for power to power the magnetron (the component which generates microwave energy) can cause a short current surge.
3. Air Conditioners:
Air conditioners may cause inrush current when the compressor starts. This initial surge is crucial to spinning up the motor and getting the cooling process underway, just like a fridge.
4. Power Tools:
Devices like drills and saws with electric motors can also produce inrush current when powered up. The motor needs an extra jolt of energy to start spinning.
Implications of Inrush Current:
1. Voltage Drops:
Inrush current can lead to momentary drops in voltage, affecting the stability of your electrical system. This can be particularly noticeable if you’re running your devices at or near the limits of you inverter’s power rating.
2. Inverter Performance
Inverters exhibit different abilities to exceed their rated output. Some models may operate above their rated output for several seconds or even longer. Others may immediately trigger an overload condition as soon as demand approaches the rated maximum. Thus some models may be able to ride out the inrush caused by your fridge while others will switch off immediately.
Even if your inverter does not self-protect, it is not a good idea to operate an inverter above its rated output for a long time or on a routine basis. The excess heat generated by this could cause premature wear and shorten its lifetime. Instead, it’s a good idea to select an inverter with at least 2 times the rated power of any inrush-susceptible device you may want to power. That gives you a good chance of avoiding problems with inrush current.
There are a few ways you reduce any inconvenience associated with inrush current when you’re powering your devices using an inverter. The simplest is just to be mindful of what you plug in and when.
If you want to switch on an appliance that might cause inrush current, it’s advisable to turn off other devices for a few seconds until the inrush has subsided.
Conclusion
Understanding inrush current and its implications is essential for users of inverters, especially when powering appliances like refrigerators and microwaves. By being mindful of the temporary surges in power demand, you can ensure a trouble-free experience. A little strategic planning and a few seconds of patience can go a long way in optimizing the performance of your appliances and maintaining the health of your inverter. If you are interesting in taking your backup power setup to the next level, visit the Electric Market and let us help you get more power, in your hands.