Translations:Electricity types/3/en
In any electrical system, whether AC or DC, all components or appliances must be rated to function with the characteristics of the electrical system - voltage, current, and frequency if AC. If they are used improperly it can lead to a failure that results in fire or injury. For DC components this will likely be 12 V, 24 V, or 48 V. AC component voltages vary significantly by country, but common ratings are 120 V, 220 V, 240 V. Common AC frequencies are 50 or 60 Hz. These ratings are called nominal voltage or nominal frequency as no electrical system is able to operate at all times at an exact value, especially stand-alone PV systems which have a highly variable form of power generation and a storage system with a voltage that will sag under heavy loads or when low on energy. Therefore all components made for use with an electrical system accept a range of voltages and frequencies that should work with other components or systems that share that similar rating (some accept smaller or larger ranges than others).