Anti-pumping device vs. Latching relay 1

[tszpun]

Hello experts

I was reading about anti-pumping device. So basically, (if i understood correctly), this device protects tripping mechanism of the circuit breaker from having too many CLOSE-OPEN loop commands, which could happen when the CLOSE command is given, when fault is not cleared.
Then, if it is correct, could somebody tell me, is this device necessary when we have "latching relay"? With latching relay whenever CB is OPEN, the operator has tp reset the relay, physically. So, thats why i i think with the latching relay this anti pumping device is not necessary. Could somebody confirm me?

Thanks

 

[davidbeach]

The anti-pump circuit is because stuff happens. Also many, perhaps most in the utility world, breakers don’t have lockout relays on them so that they can auto-reclose or be closed via SCADA. Or they get locked out for some trips but not others.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[tszpun]

Also many, perhaps most in the utility world, breakers don’t have lockout relays on them so that they can auto-reclose or be closed via SCADA.

Does it mean that if i have lockout / latching relay in the circuit breaker, the anti-pumping device is not necessary?

 

[davidbeach]

Let me repeat, "stuff happens". Things stick, standing closes exist. You probably don't really want to reset a lockout and discover that there was a standing close that didn't get blocked by the anti-pump circuit. Don't think I've seen a breaker in years that didn't come standard with anti-pump circuitry anyway, why try to get rid of it? It's not a device, in my experience, just a basic part of the breaker's internal control wiring.

I’ll see your silver lining and raise you two black clouds. - Protection Operations

 

[JezNZ]

I think your assertion might be slightly incorrect. The anti-pump device prevents operation (other than initial OPEN) when the open & close commands are simultaneous maintained. There are certainly scenarios where this can be the case (usually involving external commands).

Do NOT remove it, this is critical safety functionality.

 

[bacon4life]

Typically the anti-pump components would be part of wiring included by the breaker manufacturer. Latching relays are customer wired devices. As others mentioned, they are not substitutes for each other.

Without the anti-pump relay, a stuck close command could cause the breaker to cycle between closed and open.

 

[davidbeach]

And even then, the anti-pump circuit doesn't keep a bonkers reclosing relay from closing the breaker into the same line fault 30 some times. That becomes a good way to get an ancient oil breaker replaced with something using newer technology. I've also seen, either the other end of that line or the other end of the parallel companion line, a fault that caused a time overcurrent element to take 75 seconds to time out, but reclosing reset after 60 seconds. That one only operated 17 times before somebody got the breaker open.

So, like I said stuff happens (although there's a slightly shorter word that starts with 's' that works much better than stuff) and everything we can do to deal with "stuff" is a good thing. Belts are good. Belts and suspenders are better. Belts, suspenders, and sky hooks are far superior. Not sure what to name the fourth approach, but it can't hurt either. Cover all the bases, in depth.

It's like what I've run into on line protection; I like just adding layers but I've run into others that start removing stepped distance when they add comm assisted tripping. Look where that got ConEd, a dual loss of comms and a 138kV fault that lasted nearly 5 minutes. I don't want to make the news that way.

Layer, built on layer, built on layer. Never remove an "underlying" layer. It might bite you in the hinnie, and hard. Every breaker need an anti-pump that operates all the time. Pretty much every breaker will also have one or more lockout relays that can keep it open for certain trip. Neither replaces the other.

I’ll see your silver lining and raise you two black clouds. - Protection Operations