Bus/Jumpers – Types Flashcards
The most common type of substation in use today is the air-insulated type.
True
Common names given to bus types are main bus, ring bus, and ? bus.
transfer
One of the common methods to make connections to aluminum tubular bus is with ? .
Tungsten Inert Gas (TIG) welding
Older substations with copper rigid bus systems use welded connections.
False
Minor defects in rigid bus may be repaired by ? .
filing, then polishing with a fine emery cloth
A ? is a flexible bus consisting of a stranded conductor strung between substation structures and may be supported by suspension insulators.
strain bus-bar
Insulated bus-bar is a rigid tubular aluminum conductor installed in a larger metal tube, filled with high pressure ? gas.
sulfur hexafluoride
The type of substation bus that is a rigid bar supported by insulators and covered by a grounded metal shield is the ? bus-bar.
insulated-phase
The most common types of rigid bus-bar used in substations are flat, hollow tube aluminum, and ? .
angle
Where high-current substations are built, ? bus-bars are used because its shape allows heat to dissipate more efficiently.
hollow tube
Strain type bus-bars are used in substations primarily for ? conductors.
high voltage transmission
Hollow tube aluminum bus is the easiest type to connect to with bolt-on jumpers.
false
Because of the lower voltages on the secondary side of a transformer, a ? bus allows for closer spacing and is easier to connect with bolt-on jumpers.
flat or angle aluminum
If the load is heavy enough, two or three large copper conductors may be used per phase as jumpers.
true
Expansion and contraction of rigid bus-bars due to load variation and ambient temperature changes are small amounts and are generally disregarded by designers.
False
If multiple or parallel jumpers are used on the same phase, they must be ? .
bolted or wired together
Vibration of substation buses will occur if the spans are long enough to vibrate and the ? .
wind blows across the bus at right angles
Only round hollow aluminum substation buses will vibrate.
False
A substation bus will vibrate because the supporting insulators are rigid and cannot absorb any vibrations.
False
If a four-inch hollow tube bus is used, the support separation can be up to ? before damping should be used.
17’
