A recloser is a protection device for electrical distribution networks. It combines a circuit breaker that trips if an overcurrent is detected (indicating a short circuit somewhere in a section of the network), with an electronically-controlled reclosing function that automatically restores power to the affected line if the fault clears itself quickly – which usually happens around 80 percent of the time.
There is a double incentive
for electricity distribution companies to deploy reclosers in their networks.
1. The first is that reclosers prevent transient short circuits from triggering prolonged power outages. This results in better supply continuity to customers.
2. The second benefit is that reclosers restore power automatically, without requiring an engineering site visit.
A transient short circuit is the type of event that can be caused, for example, when a branch of a tree momentarily touches overhead cables as it falls to the ground. Reclosers handle this type of event much better than circuit breakers. Typically, power would be restored to customers in a matter of a few seconds or less. Only if the cause of the short circuit has not cleared itself would the recloser keep the breaker open until the cause is manually cleared.
Reclosers like the new ABB Gridshield also have electronic control equipment with multiple network interfaces, so the reclosers can be integrated into a wider network automation strategy. However, even with a fast-acting recloser installed in a feeder network, a transient short circuit will still cause a momentary interruption to customer supplies. But this is much preferable to a power outage that lasts until a maintenance team can get to the breaker site to restore power.
Download GridShield recloser training program
Download OVR recloser training program
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