Air Circuit Breaker

yes.. but duty cycle test differs for breakers. (i.e. between normal CB and Generator circuit breakers)

If u meant poles= Interrupters=contacts...

Assuming you are referring to IEC/IS specifications, yes, the test sequences call for additional tests on four-pole CBs to be conducted after those on the three-pole version. You need to study IEC 60947-1 and 2 thoroughly.

i am also intrigued by vijaymail's post ... i have not come across any special standards for generator CBs. Can you please elaborate ? Thanks.

Of late, I have also been coming across a lot of talk on this GCB (Generator Circuit Breaker). On analysing the name plate details of a GCB, I observed that these GCBs do not have a Short Circuit Breaking Capacity. Only, Continuous Current and making & latching current. So, though in construction they are circuit breakers, they, in fact, are being used only as Switches. Because, when the Generator is connected thro the GCB to the GT (Generator Transformer) thence to the grid, in the event of a fault in the generator side of the GCB, the entire grid would feed into the fault and the "so called" GCB would definitely not have the capacity to break this aggregate fault current feed-in. Hope I am correct.

Also, ABB's Switchgear Manual has a chapter on GCBs.

Thanks. Makes sense. Regrettably, in a misplaced surge of compassion, i gifted my copy of the ABB manual to a young engineer, so i am bereft. Must study more. Please keep sending any gems on this as and when you come across, thank you in anticipation.....

KVS, I do have a soft copy of the ABB Switchgear Manual. If you so like, I am ready to send you the same. Pl. let me know your mailID thro this forum's mailbox.

By the by, good to note that you are gifting good books to young engineers. As Bernard Shaw said, many books I have in my library have been gifted to me by my mentors. Keep up the tradition.

Thank you ever so much. i have sent you a PM (if that is what it is called in CR4)... i am grateful to you. Yes, giving away my books, notes etc, and trying to teach youngsters whenever i can during my visits to my clients....one way to leave a small part of myself for posterity

Dear Mr. electrical xperts65,

I also need the soft copy of AAB Switch Gear Manual. I request you TO SEND TO MY MAIL <email removed>

Thanks,

DHAYANANDHAN.S

CR4 Admin - email address removed

From the CR4 Rules: Do not post phone numbers or email addresses. The CR4 Admin will delete all phone numbers posted in threads or comments, and we strongly urge you not to put up email addresses. You can share this information via the CR4 internal messaging system.

Sending today! Sorry for the delay! Pl. acknowledge receipt.

Try the guys at Low Cost Controls. They always seem to be able to hunt down manuals for me, not sure if they do it for non-customers, but worth a try.

Good Luck!