In an electrical system, there are two ways to measure voltage: line-to-line voltage and line-to-neutral voltage. Here is the difference between the two:
What is line to line voltage?
The LL voltage is the electrical potential difference that exists between two phases of a three-phase or two-phase system. It is measured between two conductors (or phases) of the three-phase system and is represented by the initials L-L.
In a balanced three-phase configuration, the line-to-line voltage is the square root of 3 (approximately 1.732) times greater than the line-to-neutral voltage.
In this case there is no L-N voltage.
For example, for a three-phase “Y” system, the voltage between phase and neutral is 120V and the line-to-line voltage will be approximately 208V (120V x square root of three), as shown in figure 1.
If the system is in “Delta” there would only be LL voltage which would be 208V as shown in figure 2.
Formula to convert voltage from LN to LL:
There are also calculators that automatically convert from L-N to L-L .
The most common line-to-line powered voltages are 208V, 220V, 240V, 440V, 480V, and 600V. These voltages are commonly used in three-phase electrical systems, where electrical power is distributed across three conductor lines.
Electrical equipment that is supplied with line-to-line voltage are usually those that require more power, such as electric motors, pumps, water heaters, and industrial furnaces. They are also used in centralized air conditioning systems and in the lighting of large spaces, such as parking lots or commercial buildings.
The most common line-to-line powered voltages are 208V, 220V, 240V, 440V, 480V, and 600V. These voltages are commonly used in three-phase electrical systems, where electrical power is distributed across three conductor lines.
Electrical equipment that is supplied with line-to-line voltage are usually those that require more power, such as electric motors, pumps, water heaters, and industrial furnaces. They are also used in centralized air conditioning systems and in the lighting of large spaces, such as parking lots or commercial buildings.
What is line to neutral voltage?
Voltage LN is the electrical potential difference that exists between a phase and the reference point of the electrical system, which is generally the neutral.
It is measured between a conductor (or phase) and the reference point of the system and is represented by the acronym L-N. It is important to clarify that the neutral is different from the ground conductor, this is because the neutral can conduct return current, while that the ground conductor should not.
In a balanced three-phase configuration, the line-to-neutral voltage is equal to the line-to-line voltage divided by the square root of 3 (approximately 1.732). Although the LN voltage is found in three-phase systems as shown in figure 1, its use is also found in single-phase and two-phase systems.
For example, in a 208V three-phase system, the line-to-neutral voltage would be 120V. This is because each phase has a voltage of 120V relative to the neutral conductor.
Formula to convert voltage from LL to LN:
There are also calculators that automatically convert from L-L to L- N .
Line-to-neutral voltage is important in low-power applications such as lighting equipment and appliances.
The 120V line-to-neutral voltage is commonly used to power low-wattage electrical appliances and equipment, such as lamps, televisions, computers, and fans.
Difference Between L-L and L-N Voltages
L-L (line-to-line) voltage refers to the electrical potential difference between two phases of a three-phase system. In a three-phase system, each line or phase has an alternating voltage signal that is 120 degrees out of phase with respect to the other two lines or phases. The LL measurement is important to know the voltage that is supplied to high power three-phase electrical equipment such as motors, compressors and transformers.
On the other hand, LN refers to the line-to-neutral voltage, that is, the electrical potential difference between a current or phase conducting line and the neutral of a single-phase or three-phase system with star connection.
In a single-phase system, there is a conductive line and a neutral, while in a three-phase system with star connection, there is a conductive line connected to one of the phases and a common neutral to all three phases.
L-N measurement is important to know the voltage supplied to low power single phase or three phase electrical equipment such as lamps, televisions, computers and fans.