The protection arrangement for an electrical system should cover the whole system against all possible faults. Line protection concepts, such as overcurrent and distance arrangements, satisfy this requirement, even though short circuits in the busbar zone are cleared after certain time delay. But in the case, unit protection disused for feeders and plants, the busbar is not inherently protected. Busbar have typically been left without dedicated protection, from the following reasons:
- the busbars and switchgear are highly reliable
- it was believed that inadvertent operation of busbar protection might cause cascade tripping
- it was believed that electrical system protection or back-up protection would
give adequate bus protection if necessary Aluminum busbars are typically split into three families
-Low Voltage Busbar (up to 600V)
-Medium Voltage Busbar (between 600V and 38,000V)
-High Voltage Busbar (above 38,000V)

The advantage of aluminium busbar used in high voltage equipment
- limitation of consequential damage
- busbar fault clearance in less time than could be accomplished by back-up line protection, with the object of keeping system stability