A lineman needs to open a URD elbow to switch a loop feed that is carrying about 150 A. The cabinet has 200 A loadbreak elbows and 600 A deadbreak elbows. Which one may he operate energized? Decide first.
The 200 A loadbreak elbow. The load is 150 A, which is inside its 200 A rating, and a loadbreak elbow is built to make and break load current. The 600 A deadbreak elbow at the same current must still be de-energized before anyone touches it, because it has no load-break rating at all. Both parts are IEEE 386 separable insulated connectors: plug-in elbows that connect a URD cable to a bushing inside a padmount cabinet. The difference is whether they are rated to switch live.
A 200 A loadbreak elbow is designed to be operated energized, switched under load up to 200 A. Its mating parts are built to interrupt that current cleanly and survive the arc when the contacts part. A 600 A deadbreak connector has no load-break rating, so you open the circuit upstream first and confirm it is dead before you operate it. Loadbreak means switch it live up to its rating; deadbreak means kill it first, every time.
This is why padmount switchgear in a URD loop-feed scheme uses switchable elbows. A loop feed brings two sources into the same cabinet, one from each direction. Two source-side loadbreak elbows let an operator transfer the feed from one direction to the other, so a section of cable can be isolated for work without dropping every customer on the loop. That transfer happens under load, which is exactly what a loadbreak elbow is rated to do and a deadbreak connector is not.
The split between the two classes is mostly about current. A loadbreak elbow tops out at 200 A continuous. A circuit that runs above 200 A continuous needs the 600 A deadbreak class, which carries the higher current but gives up the ability to switch live. You switch it dead: open the breaker or upstream device, verify zero voltage, then operate the connector. Specify the class by the circuit’s continuous load first, then plan the switching around what that class allows. Guessing wrong here is not a paperwork error. Treating a deadbreak connector as if it were switchable is how a worker ends up pulling an energized 600 A connector apart by hand.
Every component on this list, conductor, switchgear, cutouts, regulators, carries its own lead time and supplier landscape. DistroForge report editions track capacity and lead times across the distribution equipment categories covered in this track.