Circuit Breaker

anti pumping ---available in google search. if you mean aunty pumping????.....

IEC 60947-1 definition 2.3.20:

A device which prevents reclosing after a close-open operation as long as the device

initiating closing is maintained in the position for closing.

However, there is no separate 'device' as such in modern CBs. The mechanism is so designed as to take care of this. Electrical antipumping is also offered by some, by giving a momentary closing command even if the input is a sustained command.

When a LOR is used will the anti-pumping relay be bypassed?.

I agree, but I have seen electrical anti pumping relays which also cut off the closing circuit even if the circuit breaker fails to close. The concept is that the anti pumping relay is energised simultaneously with the close signal to the CB close coil, but it has a time delay before it cuts the closing circuit. I guess the idea is also to avoid continuous energisation of the closing coil in the event of a stuck breaker.

This was necessary when closing solenoid coils were short-time rated and were susceptible to burnout if the supply was continously given, and the CB failed to close (a NC contact of the CB was used to cut off supply to the closing coil). However, modern trend is to have closing/shunt/undervoltage coils which are electronically controlled, and, as i mentioned before, the closing (and shunt-trip too) coils get a momentary (say 50ms) command, even if the incoming command to close (or trip) is a sustained one. This saves a couple of aux contacts of the CB and also, in the case of the closing solenoid, gives electrical antipumping.

Mechanical antipumping, which is the best way, is achieved by a nice "escapement" system in the closing linkage.

You are right.But, an electrical antipumping scheme should also be provided to serve as a back up since, mechanical "escapement" in the closing linkage may fail due to obvious reasons.Further,mechanical arrangement being an in-built feature of the CB,user has to depend on the manufacturer in case of any mal-function; whereas, he can easily rectify the electrical scheme if required.Hence, we recommend the electrical antipumping scheme to our clients.

i appreciate your viewpoint, and i believe in providing redundancy where safety is concerned. However, i would urge you to study the escapement design of the following LV CBs..... Schneider Electric's MASTERPACT, ABB's EMAX and CS Electric's WiNmaster. There is negligible or no chance of failure of the escpement. Anyway, the microprocessor-controlled closing coil gives electrical anti-pumping too as a backup in case of the CS Electric ACB,

Thanks a lot.I would certainly like to study the suggested litreature.Can you please provide relevant links ,if possible,for my reference as well as for benefit of the forum?

Regards.

S PRADHAN

Dear Mr Pradhan, i had not forgotten this .

Just that i was searching for some links which mention this. Regrettably, nobody does. i also have many patents of various companies, and again, there is no specific mention of this antipump feature. Nevertheless, this feature is avaialble in almost all modern LV ACBs. i am afraid that a video of a CAD simulation will be the best way to understand. i am willing to send this to you, and answer the queries you will have on it. i will try to send the video clip through the CR4 mail system.

CR4 mail system does not allow attachments. So, i am giving here some images which may be enough to explain the action :

(This is my own design, and has no IP issues )

Wonderful design!Nice images!!But,I'd still prefer to go for an electrical antipumping scheme as aback up to this in-built mechanical antipumping feature.

Thanks.

Lay me understand the requirement of antipumping:

What does a complex antipump scheme do? It prevents reclosure of the CB after ONE closing operation. Right?

In my design, the closing coil gets only ONE pulse of 50 milliseconds. No matter how long the closing command is maintained.

So i submit : (a) i have mechanical antipumping which functions even if an operator holds the closing pb in depressed position for a long time. Also works for an electrical command through the coil and (b) i have a microprocessor-controlled closing coil which operates ONCE per closing pulse. If i have to close the CB again, i need to switch OFF the closing command, so the pcb re-arms itself, and then re-apply the closing command.

In fact my deisgn prevents closing of the CB if (a) there is trip command already present and (b) if the CB is already on. Not unique, everyone in LV ACB field has it.

Now, it is possible that i am unaware of some other feature that is offered in an external antipump scheme. i would like to know more, please respond, thank you.

I sincerely honour your expertise & experience in the field of LV ACB design. You need not doubt your fundmental knowledge base.But you will appreciate the fact that,the life of any mechanical device is poorer than it's electrical counterpart.The actual user's(who runs and maintains the system/equipment )confidence level is an important criterion for selection of the concerned equipment/system.Particularly, when it serves a production shop in which, availability of shutdown for routine maintenance is very rare.The PSU client we are working with, does not mind investing more on back ups,back ups to back ups,redundancies etc since , any loss of production due to outage of power supply ,will offset the savings made on account of non-provision of back ups.

Hope ,this satisfies

In locations where a LOR is used will the anti-pumping device be bypassed?.

Somewhere on this page, there is an excellent explanation of why a lockout relay cannot replace an antipump relay. Excellent link provided by vinodh on another thread...

http://electrical-engineering-portal.com/anti-pumping-and-lockout-relays

Here's the link for EMAX breaker section from ABB low voltage product selection guide.

http://www.clrwtr.com/PDF/ABB-Controls/ABB-Emax-Power-Breakers.pdf