SELECTION OF KAIC RATING 1

[khank4u]

HI CAN ANY ONE TELL ME SHORT CIRCUIT CURRENT RATING (KAIC) SELECTION DEPENDS ON BREAKER OR BUSBAR. IF WE HAVE TO SELECT ACCORDING TO BREAKER SIZE. WHAT IS THE TECHNICAL REASON.

 

[jraef]

AIC means "Amps Interrupting Capacity", the k is shorthand for thousand. So if a breaker says it is 65kAIC, that means it can survive the physical forces that take place when interrupting a fault current level of 65,000 Amperes and interrupt the flow of current without becoming a bomb.

Selection has nothing whatsoever to do with bus bars or breaker trip ratings. It has ONLY to do with the Available Fault Current in your system, in other words the MAXIMUM amount of current that your power utility (or generator) can deliver in the event of a fault in the system down stream of the breaker.

If you do not know what this means, then you are not the right person to be making this decision. It is not something to be taken lightly. You should defer this task to someone with the proper qualifications.


"Will work for salami"

 

[waross]

For the purpose of equipment rating the symmetrical short circuit current, calculated from the transformer percent impedance voltage, is used.
The actual fault current and the actual capability of the equipment is often asymmetrical and may approach the peak to peak value of the symmetrical current.(Over twice the symmetrical value.) If you are selecting equipment based on the available short circuit current, use the symmetrical current value or your equipment may be over spec'ed and more expensive than it has to be.
To borrow a phrase from jraef;
"If you do not know what this means, then you are not the right person to be making this decision. It is not something to be taken lightly. You should defer this task to someone with the proper qualifications. "

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ScottyUK]

If you have local generation you must consider the effect of high X/R ratio and also the high asymmetric peak current. The former places greater demand on the breaker, while the latter places greater stress on the bus bracing. If you don't know what this means then swallow your pride and ask for help from someone qualified to give it. The internet is a great resource but it's no substitute for a qualified and experienced engineer with all the information relating to your installation available to him.

 

[khank4u]

HI,
I NEED TO KNOW WHAT IS THE STANDARD SIZE OF ELECTRICAL ROOM. AS I HAVE ONLY THE PLOT AREA NOT A BUILDING PLAN... 20116 SQ.M. AND ALSO WHAT SHOULD BE THE MINIMUM DISTANCE BETWEEN ELECTRICAL ROOMS. AS IN OUR OFFICE WE HAVE CONFLICT THAT BECAUSE I HEARD THAT THE EVERY 60 METER THERE SHOULD B ONE ELECTRICAL ROOM. AS I KNOW TO REDUCE THE VOLTAGE DROP FOR THE CIRCUITS AND DEPEND UPON THE PANELS AND ROOM AREA WE SELECT THE ELECTRICAL ROOMS. CAN ANY ONE TELL ME WHAT IS THE STANDARD SIZE AND WOYHOUT ANY PLAN HOW V CAN DECISDE HOW MANY ELECTRICAL ROOMS REQUIRED AND THE ELECTRICAL CLOSET.
HOPING FOR A QUICK RESPONSE FROM SOME OF THE GOOD ELECTRICAL ENGS.

 

[LionelHutz]

The interrupt rating depends on all the equipment in the system.

The standard electrical room size is big enough to house the required equipment plus room for future expansion.

 

[EEJaime]

khank4u,
These are basic design questions that need to be addressed by someone with the experience and knowledge about the basic system components you are describing. There are many factors that go into the solutions to the questions you are asking. And to all of the questions you are not asking. You REALLY need to follow jraef and ScottyUK's advice and get an engineer to look at this and apply actual engineering principles to the problems. There is no such thing as a "STANDARD SIZE" for any of this.
Good luck,
EEJaime