vaihejohdon

Vaihejohdon is a term from electrical engineering that refers to a phase conductor in a polyphase electrical system. In systems with multiple alternating current phases, a vaihejohdon carries one phase of the electrical supply relative to the others. In common three-phase systems there are typically three vaihejohdot, often labeled L1, L2, and L3, along with a neutral conductor (N) and a protective earth (PE) in four-wire configurations.

Construction and materials commonly involve copper or aluminum conductors that are insulated to withstand the system voltage. The insulation may be made of materials such as PVC or XLPE and the conductors can be solid or stranded depending on the application. Color coding helps identify phase conductors and their voltage level, with standards varying by region. In many European contexts, the phase conductors are identified separately from the neutral and earth to reduce the risk of accidental contact with live parts.

Function and usage in electrical systems center on delivering electrical power from sources such as transformers or generators to loads like motors, lighting, and electronics. The vaihejohdon carries voltage that is phase-shifted relative to other phases in the system, which enables efficient power distribution and the operation of three-phase equipment. It is distinguished from the neutral, which provides a return path for current, and from the protective earth, which is a safety path to ground.

Safety considerations are essential when handling vaihejohdot, as they can carry dangerous voltages. Proper insulation, secure connections, and adherence to local electrical codes are required to prevent shock, short circuits, and fire hazards.