1 Answer
The number of volts in AC (alternating current) depends on **where** and **how** it's being used, because AC voltage can vary depending on the country, application, and context (household, industrial, transmission, etc.).
Let’s break it down clearly so that anyone can understand:
---
### **Standard Household AC Voltage**
Most people asking "how many volts is AC?" are usually referring to the voltage supplied to homes and buildings. This varies by country:
#### **Common Household AC Voltages**
* **United States, Canada, Mexico, and parts of Japan:**
➤ **120 volts** AC (sometimes called 110V or 115V; it's nominally 120V at 60 Hz)
* **Most of Europe, Asia, Africa, and Australia:**
➤ **230 volts** AC (sometimes referred to as 220V or 240V; it's nominally 230V at 50 Hz)
---
### ⚙️ **Industrial and Commercial AC Voltages**
In factories or commercial buildings, AC power is often supplied at **higher voltages** to support heavy machinery. Examples include:
* **208V, 240V, 277V, 480V (US)**
* **400V or 415V (Europe, Asia)**
These are usually **three-phase** systems, which are more efficient for running large motors or heavy electrical loads.
---
### **High Voltage AC (Power Transmission)**
For long-distance power transmission, very high voltage AC is used to reduce energy loss:
* **Common transmission voltages:** 11,000V (11kV), 33kV, 132kV, 400kV, or even higher.
* These voltages are **stepped down** by transformers before reaching homes and businesses.
---
### ⚠️ Important Notes
* **AC voltage is not constant.** It alternates in polarity and magnitude — this is why it’s called “alternating” current.
* The voltage values mentioned above are **RMS (Root Mean Square)** values, which represent the effective voltage (kind of like the average usable power).
* The **peak voltage** of a 120V AC signal is actually about **170 volts**, and for 230V AC it's about **325 volts**, but RMS is what's usually quoted.
---
### Summary Table
| Region / Use Case | Voltage (RMS) | Frequency |
| -------------------- | ------------- | --------- |
| USA/Canada (homes) | 120V | 60 Hz |
| Europe/Asia (homes) | 230V | 50 Hz |
| Industrial (US) | 208V–480V | 60 Hz |
| Industrial (EU/Asia) | 400V–415V | 50 Hz |
| Transmission lines | 11kV–400kV+ | 50/60 Hz |
---
Would you like a diagram or map showing voltage standards by country?
Let’s break it down clearly so that anyone can understand:
---
### **Standard Household AC Voltage**
Most people asking "how many volts is AC?" are usually referring to the voltage supplied to homes and buildings. This varies by country:
#### **Common Household AC Voltages**
* **United States, Canada, Mexico, and parts of Japan:**
➤ **120 volts** AC (sometimes called 110V or 115V; it's nominally 120V at 60 Hz)
* **Most of Europe, Asia, Africa, and Australia:**
➤ **230 volts** AC (sometimes referred to as 220V or 240V; it's nominally 230V at 50 Hz)
---
### ⚙️ **Industrial and Commercial AC Voltages**
In factories or commercial buildings, AC power is often supplied at **higher voltages** to support heavy machinery. Examples include:
* **208V, 240V, 277V, 480V (US)**
* **400V or 415V (Europe, Asia)**
These are usually **three-phase** systems, which are more efficient for running large motors or heavy electrical loads.
---
### **High Voltage AC (Power Transmission)**
For long-distance power transmission, very high voltage AC is used to reduce energy loss:
* **Common transmission voltages:** 11,000V (11kV), 33kV, 132kV, 400kV, or even higher.
* These voltages are **stepped down** by transformers before reaching homes and businesses.
---
### ⚠️ Important Notes
* **AC voltage is not constant.** It alternates in polarity and magnitude — this is why it’s called “alternating” current.
* The voltage values mentioned above are **RMS (Root Mean Square)** values, which represent the effective voltage (kind of like the average usable power).
* The **peak voltage** of a 120V AC signal is actually about **170 volts**, and for 230V AC it's about **325 volts**, but RMS is what's usually quoted.
---
### Summary Table
| Region / Use Case | Voltage (RMS) | Frequency |
| -------------------- | ------------- | --------- |
| USA/Canada (homes) | 120V | 60 Hz |
| Europe/Asia (homes) | 230V | 50 Hz |
| Industrial (US) | 208V–480V | 60 Hz |
| Industrial (EU/Asia) | 400V–415V | 50 Hz |
| Transmission lines | 11kV–400kV+ | 50/60 Hz |
---
Would you like a diagram or map showing voltage standards by country?