for lt breaker

What is the continuous load amps?

If any breaker specifically states it is rated for 100%, it is. If it does not clearly state that, you must assume it is rated for 80% of it's stated rating continuously. Continuous is defined as in excess of 3 hours (I believe).

That said, most Power Breakers such as an ACB are purchased in switchgear as 100% rated devices. Check the documentation on the equipment. In any case, you are playing with fire if you are running at nearly 110% of rated, unless by "jerk load" you are meaning a very short duration at that higher value. Typically you will have at the very least a "Long-time" (L) and Instantaneous (I) trip setting. The, L setting will be based on I²t of the rating, with the maximum time value at 110% load being somewhere in excess of 2 hours. You can request what is called a "trip curve" from the manufacturer of your ACB.

All ACBs are rated for short duration overloads ranging from 20 % overload to breaking capacity of the breaker.

10 % overload for 1/2 an hour need not be a worry.

Manufacturer's specification ( which generally appears on name plate may be refered.)

wat s the maximum current the load can take ? i mean is it ok for the load to take 4350 amps ? if so then select acb nw50 (MG)along WIT A MICROLOGIC and set the micrologic to trip after the max current which the load can take to run safely

I didnt understand your logic, please make it clear

I didnt understand your logic,so please make it clear

K tell me one thing what happens to the load when it gets 4350A.....i want to know whether the load would withstand such current....if it does thn select a acb of rating 5000A .....after selecting tht acb , u need to additonally select a micrologic for tht acb....in tht micrologic u can set the trip current for 0.4, 0.5, 0.6...1 times acb rated current....for more details visit schneider website and search for acb and micrologic....................

Dear Guest,

You have mentioned the load goes to 4350 A on jerk load. what is the duration of jerk load ? regarding the capacity of ACB, there are certain additional factor to be considered : what is the ambient temperature? what is the temperature rise accepted inside the enclosure? if you could furnish the sld/electrical scheme, then the forum members can provide a better solution.

Thanking you

Please Note : it would be nice if could introduce yourself.

Has the circuit breaker ever tripped? If the 4350 amp surge subsides quickly, and the continuous load is somewhat less than 4000 amps, and there has been no tripping, then you are probably okay. I agree with the other recommendations to check the trip curve for this unit.

You might also consider some control strategies, such as unloading some other equipment when starting a large motor. Or starting your largest loads first and your smallest loads last.

The breaker size is to protect the wiring or bus, some way of limiting inrush will have to be done