Three Types of Cutouts
Three types of Cutouts
When it comes to cutouts almost all distribution systems in the United State use one of three types of cutouts; Interchangeable, Loadbreak, or Linkbreak.
Interchangeable cutouts are by far the most common style of cutout. All major cutout manufactures manufacture an interchangeable cutout. Interchangeable means that the fuse holder from one manufacturer can be interchanged with the fuse support from another. This interchangeability is demanded by most utility because the intractability means they can more easily service the lines and not have to match the replacement fuse holder with the correct manufacturer’s fuse support.
Loadbreak cutouts are the second most common style of cutout. These cutouts are not interchangeable between manufacturers but what is lost in interchangeability is gained by increased safety and ease of use. A Loadbreak cutout is easily recognizable by is large arc-chute. This mechanism provides the ability for a cutout on a live circuit to be opened without the use special tooling. Typically, if a live cutout is opened there will be a large arc generated as the contacts open. You may have seen tiny version of this arcing if you have ever quickly unplugged a powered fan or vacuum. The arc-chute contains the arc making cutouts safer to operate.
Linkbreak cutouts are the least common but also allow for easy operation. These cutouts contain an additional feature on the fuse holder. Most manufacturers of linkbreak cutouts and fuse holders state that their linkbreak fuse holder can be fitted with any interchangeable fuse support. What the linkbreak feature does is allows a lineman to manually break the fuse inside of the folder. While this destroys the fuse link it allows the, now de-energized, cutout to be opened without using special tools and it will not create a dangerous arc.
Post written by Michael Murphy