# Rated Voltage

on . Posted in Electrical Engineering

Rated voltage is the voltage level at which an electrical or electronic device is designed to operate optimally and safely.  It is the voltage at which the device can perform its intended functions without risking damage or malfunction.  For example, in the case of household appliances, the rated voltage might be 120 volts or 230 volts, depending on the region's electrical system.  Similarly, electronic devices like computers or smartphones have a rated voltage that ensures they function correctly when connected to a power source within that voltage range.  Exceeding the rated voltage can lead to overheating, component damage, or even electrical hazards.

### rated Voltage formula

$$V_r \;=\; \sqrt{P_r \ R}$$     (Rated Voltage)

$$P_r \;=\; V_r^2 \;/\; R$$

$$R \;=\; V_r^2 \;/\; P_r$$

Symbol English Metric
$$V_r$$ = rating voltage $$V$$ $$kg-m^2 \;/\; s^3-A$$
$$P_r$$ = rated power $$P$$ $$kg-m^2\;/\;s^3$$
$$R$$ = normal resistance $$\Omega$$ $$kg-m^2\;/\;s^3-A^2$$

### Operating Voltage

Operating voltage, in the context of electrical or electronic devices, refers to the voltage range within which the device is designed to function properly.  It's the range of voltages that the device can tolerate while still performing its intended functions safely and efficiently.

For example:

• In the case of electronic gadgets like smartphones or laptops, the operating voltage might be specified as 3.3 volts to 5 volts for the internal components to function correctly.
• For household appliances like refrigerators or washing machines, the operating voltage might be 110 volts to 120 volts or 220 volts to 240 volts, depending on the region's electrical standards.
• In industrial machinery, the operating voltage can be higher, such as 208 volts, 240 volts, 480 volts, or even higher, depending on the equipment's power requirements.

Operating voltage is a critical consideration during the design and manufacturing process because exceeding this voltage range can lead to damage, malfunction, or even safety hazards.  Manufacturers typically specify the operating voltage range in the device's datasheet or user manual to ensure proper usage and prevent potential issues.

### Normal Voltage

Nominal voltage is the level of electrical power in a system.  Nominal voltage is a crucial part of voltage systems because it builds the foundation upon which we can communicate about voltage systems.  It indicates the standard and foundational nominal voltage at which something was installed.  In turn, it tells us what range the system best operates in.  Normal voltage can vary depending on the context in which it's used.

• Household Electrical Systems  -  In many countries, the standard or "normal" voltage for residential electrical systems is either 120 volts or 230 volts, depending on the region's electrical grid standards.  This voltage is what most electrical outlets provide for powering household appliances and devices.
• Industrial and Commercial Electrical Systems  -  In industrial and commercial settings, normal voltage can vary widely depending on the specific requirements of the equipment and the infrastructure in place.  It might be 208 volts, 240 volts, 480 volts, or even higher, depending on the needs of the machinery and equipment being used.
• Power Grids  -  In the context of power grids, normal voltage refers to the typical voltage level of the electricity being transmitted across transmission lines and distributed through substations.  This can vary depending on factors such as the capacity of the grid, the distance of transmission lines, and local regulations.  For example, in the United States, typical transmission voltages can range from 69 kV to 765 kV.
• Electronics  -  In electronic circuits and devices, normal voltage can refer to the operating voltage range specified by the manufacturer.  For example, a microcontroller might operate with a normal voltage range of 3.3 volts to 5 volts.

### Voltage Supply

• Low Voltage Supply  -
• Low voltage typically refers to electrical systems or circuits that operate at lower voltage levels compared to standard household voltages.  While there isn't a universally agreed-upon threshold for what constitutes low voltage, it generally refers to voltages significantly below typical household voltages, which are around 120 volts or 230 volts.
• Low voltage typically implies a lower risk of electrical shock and reduced power levels compared to higher voltage systems.  However, even low voltage systems must be designed and operated safely to prevent electrical hazards and ensure reliable performance.
• Medium Voltage Supply  -
• Medium voltage typically refers to electrical systems or circuits that operate at voltage levels higher than low voltage but lower than high voltage.  The precise range defining medium voltage can vary depending on the context and industry standards, but it generally falls within the range of 1,000 volts to 69,000 volts AC or 1,500 volts to 100,000 volts DC
• Medium voltage systems require specialized equipment, such as transformers, switchgear, circuit breakers, and protective devices, designed to handle the higher voltages safely and efficiently.  Additionally, safety precautions and maintenance procedures are crucial when working with medium voltage systems due to the increased risk of electrical hazards compared to low voltage systems.
• High Voltage Supply  -
• High voltage refers to electrical systems or circuits that operate at significantly higher voltage levels compared to low voltage and medium voltage systems.  While there isn't a precise threshold universally defining high voltage, it typically starts at voltages above 69,000 volts AC or 100,000 volts DC.
• Extra-high voltage systems are primarily used for long-distance transmission of electricity from power generation facilities to major load centers, such as urban areas or industrial zones.  By transmitting electricity at higher voltages, power losses due to resistance in transmission lines can be minimized, making the overall transmission process more efficient.
• High voltage systems require specialized equipment, including transformers, circuit breakers, insulators, and protective devices, designed to handle the increased voltage levels safely and reliably.  Additionally, working with high voltage systems requires strict adherence to safety protocols and regulations to prevent electrical hazards and ensure the safety of personnel and equipment.
• Extra-high Voltage Supply  -
• Extra-high voltage (EHV) refers to the highest voltage levels used in electrical power transmission and distribution systems.  While definitions may vary slightly between regions and standards organizations, extra-high voltage typically refers to voltage levels above 230,000 volts AC or 320,000 volts DC.  These voltage levels are significantly higher than those used in standard high voltage systems.
• Extra-high voltage systems are primarily used for long-distance transmission of electricity from power generation facilities to major load centers, such as urban areas or industrial zones.  By transmitting electricity at higher voltages, power losses due to resistance in transmission lines can be minimized, making the overall transmission process more efficient.
• Extra-high voltage systems play a crucial role in modern electrical grids by enabling the efficient and reliable transmission of large amounts of electricity over vast distances, supporting economic development, and meeting growing energy demands.
• Ultra-high Voltage Supply  -
• Ultra-high voltage (UHV) refers to the highest voltage levels used in electrical power transmission and distribution systems, surpassing even extra-high voltage (EHV).  While there isn't a universally agreed upon threshold for defining UHV, it typically refers to voltage levels above 800,000 volts AC or 1,000,000 volts DC.
• UHV systems represent the pinnacle of power transmission technology and are characterized by their ability to transmit large amounts of electricity over extremely long distances with minimal losses.  These systems are primarily used for interconnecting large scale power generation facilities with distant load centers, enabling the efficient transfer of electricity across vast geographical regions.
• Ultra-high voltage systems represent a cutting-edge solution for addressing the challenges of long distance power transmission, enhancing grid reliability, and enabling the integration of renewable energy resources on a global scale.  As energy demands continue to rise and the transition to a more sustainable energy future accelerates, UHV technology is expected to play an increasingly important role in shaping the modern electric grid.

Tags: Electrical Voltage