E – 1655 High Voltage Busbar Protection

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 is used for feeders and plants, the busbars are not inherently protected.

It is a fact that the risk of a short circuit happening on modern metal clad equipment is insignificant, but it cannot be completely dismissed. Nevertheless, the damage resulting from one short circuit may be huge, up to the overall loss of the substation by fire. Severe damage or destruction would possibly end in widespread and prolonged supply disruption.