Medium-voltage lines (750–34,500 V)

Medium-voltage lines are at the top of power poles. They may look harmless, but they are extremely dangerous.

These are the two most common configurations of medium-voltage lines:

  • A single line without an insulating sheath mounted on a porcelain insulator
  • Three wires without an insulating sheath mounted on porcelain insulators

While work is being done, workers, equipment and materials should be kept at least 3 m away from medium-voltage lines at all times.

While work is being done, workers, equipment and materials should be kept at least 3 m away from medium-voltage lines at all times.

If so, is any part of the equipment liable to get within 3 m of a medium-voltage line while work is being done?

Recognizing dangerous lines

Low-voltage lines (120–600 V)

The term “low-voltage” may suggest that these lines do not pose any danger. But that’s not the case. Even 120-V lines can transmit hundreds of amperes, enough to cause a serious accident.

These are the two most common configurations of low-voltage lines:

  • Two wires with a black insulating sheath, twisted around a bare metal wire
  • Three stacked wires with an insulating sheath