johtojännitteisiä

johtojännitteisiä is a Finnish adjective used to describe electrical equipment or components that operate with or are exposed to line voltage, i.e., mains electricity. The term combines johtojännite (line voltage) with the suffix -inen, and its plural form johtojännitteisiä is used when modifying plural nouns (for example, johtojännitteisiä laitteita). It contrasts with alhaisjännitteisiä, meaning devices designed to operate at low voltage.

In practice, johtojännitteisiä devices are those connected to the mains supply and therefore presenting a potential hazard if accessed while energized. They are common in household and industrial electronics and are typically associated with voltages around 230 V AC in Finnish domestic networks, though exact values depend on the regional electrical system. Documentation, safety standards, and product descriptions often label equipment as johtojännitteistä to indicate the need for appropriate safety measures.

Safety and handling considerations are central to the concept. Exposed conductive parts of johtojännitteisiä equipment can cause electric shock or arcing, and improper maintenance or servicing while energized increases risk. Protective measures include proper insulation and enclosures, segregation from low-voltage circuits, grounding, and the use of protective devices such as fuses or residual current devices (RCDs). Work on such equipment is generally restricted to trained personnel and often requires de-energization before inspection or repair.

Examples of johtojännitteisiä devices include many household appliances, lighting fixtures, and power tools. By contrast, equipment designed for low voltage or isolated control circuits may be described as alhaisjännitteinen. See also alhaisjännitteinen, sähköturvallisuus.