I have a very very basic question, but it seems that I can’t find an answer that satisfies my curiosity
What is the difference between a Circuit breaker and a Recloser?
A recloser is a circuit breaker designed for the specific application to overhead lines for the purpose of interrupting and then restoring supplies after a transient fault.
Regards
Marmite
Reclosers are generally lighter duty, and less expensive than circuit breakers. Reclosers have lower short circuit ratings and are not available in high continuous current rating compared with breakers.
They are similar devices built to different standards. Cooper used to have a device that could be called either one, since it was built to meet both IEEE C37.60 and C37.04.
There's another aspect - size. Breakers are usually of such a size and weight that they can only be mounted on the ground or a platform. Reclosers are light enough and small enough that they can be mounted on a pole.
I rgink that a recloser is a circuit breaker that opeates with cysles OPEN-CLOSE O-C-O, e.g. when a fault appears the recloser opens, then it tries to close , if the fault is not there it remains closed, if th faults still exists makes another cycle and finally trips open. It is used in overhead lines, where we have temperary faults due to thunderstorms.
Consiter other issues with reclosers, and some circuit breakers, like oil, reduced BIL (mostly at 34.5kv), closer bushing spacing, battery issues, people knoledge about device, training, documentation of settings and parts availability.
AS jghrist mentioned, reclosers have brains, breakers do not. Also, a breaker can be used as a recloser in conjunction with relaying,but has to be derated
"a breaker can be used as a recloser in conjunction with relaying,but has to be derated "
can you explain me a little more about this. We have a client that want to add reclosing on his circuit breaker, what do we have to derate and how much? The interrupting rating?
Also i know that we have to look if the charging time of the closing coil is less than the reclosing delay. You cannot close before the breaker is charge.
tem1234, i am not sure for the derating question in my experience that comes from oil breakers, but has no effect in the gas cb. a gas cb is designed to withstand the rated interruption. most cb's either have logic built in (most commonly an Agastat time delay) in the closing circuit, or have a delay in the relaying - this is not required for the first operation.
the timing that i am aware of for a spring mech cb as a recloser can have an immediate O-C, and O- then a short time delay - required to charge after opening again ~13seconds, and then the final time will stay open to be reset manually.
if there is a hydraulic mech it can go for 6, sometimes 7, operations before being recharged.
this is a scheme that i am familiar with. would like to hear of others.