AUTO RECLOSER
Amala Joseph
Electrical Protection, Testing and Commissioning Engineer at Aura Engineering LLC | PDO Approved Testing Engineer | MIC-North PDO
RECLOSER
- Also known as Reclosers
- A mechanism that can automatically close the breaker after it has been opened due to a fault.
- Mostly used in transmission lines
In our power system, only a less number of fault is permanent, others are semi transient or transient in nature.
So during transient or temporary fault circuit breaker will opens, after some predetermined time called as dead time, recloser will try to close the circuit breaker and monitors the system for some another predefined time called as reclaim time.
If the fault still persists or appears again with in the reclaim time then the recloser will tri the lockout relay (that is, it will open the breaker and block the auto recloser operation/function until reset the lockout relay).
Sequence of operation of recloser – it describes that how many close open can be allowed for recloser. Settings depends on customer requirements.
For Example, Operation sequence will be O-t1-CO-t2-CO-t2-lockout. Normally t1 range is 0.1–0.3s; while t2 range is 1–3s. It has 2 reclose operation. Some cases we will provide only one reclose operation also.
Example
For instance, a tree limb blown off a tree during a windstorm that lands on the power line may cause a short circuit that could cause damage. However, the fault could quickly clear itself as the limb falls to the ground.
Reclosers are programmed to automate the reset process and service restoration. The result is increased availability of supply.