Schneider Electric NSX Micrologic1-5,6

You did get an acceptable reply .... an RCBO will trip on an earth leakage of 30mA all the way up to 10 or 15kA.

Not good enough for you?

Micrologic has the feature all right, not only for NSX, also for NS and Masterpact. It still needs a CBCT to sense earth leakage.

This is my last post to you since you insist on remaining anonymous.

i am batman. common, what difference does it make, to know my identity when i am asking a valid question. you are not being rational here.

i didn't get an acceptable reply , that's why i commented again .http://cr4.globalspec.com/comment/782337/Re-Earth-Fault-Leakage-Circuit-Breaker.

i will be remaining anonymous as long as it takes.

i am not being rude, i just want some answers. coming back to this question

according to my knowledge CBCT is for detection of small currents and not large. its used for earth leakage detection and not earth fault detection. also in micrologic, there s no provision to connect CBCT . if CBCT has to be used , it must be connected to ELR which inturn must be connected to shunt trip coil or undervoltage coil of the breaker. and also for normal MCB there is no proper document saying that it will trip on a phase to ground fault.

anyways i am harry from al-ain, uae

GA to you KV, I have used Masterpact 4000A with built in GFI 6.0 and they worked perfect at the farm.

Thanks Jim. Glad you have a good experience with the Schneider Masterpact 4000A. i always considered it a masterpiece of design, the constraints on the designers were stupendous, and they still delivered ! i take my hat off to them. Many times, i used to tell my team at GE "We should strive to make a product which will make people say 'Gosh! i wish i had designed that !!!' " The Schneider products, also some of the ABB ones, were in that class.

i had a superlative team, and we did some great products too. i hope you will use some of them sometime....

1) Does a normal MCCB protect against phase to ground faults

YES. MCCB detects ph-gnd faults as overload on faulted phase. However, it takes more time than CBCTwith ELR/ELCB.

2) If no, is Micrologic 6 the only option for protection against ground faults. because ELCB or Vigi modules are only for earth leakage protection.

Ques doesnt matter. bcoz answer to 1st ques is Yes.

3) If yes, why specify it as a separate term or a additional feature in Micrologic 6.

Already answered in 1st question. Takes less time since it works on residual circuit principle.

now it makes much more sense.thank you for your help.

also can i get any relevant document supporting your answer.

One small point.... the breaker will sense the eath fault as an overload only when it is > 130% of the rated current, is it not so? If yes, it will not act in the event of an earth leakage or earth fault (this terminology is only semantics. In USA, they are all called ground faults...GFCI is what the RCCB is called over there) below this current. This is dangerous, so it is always better to give earth fault protection.

Sensing can be done by CBCT or by 4 separate CTs one on each phase + one on neutral, summed up. One can perhaps also use Hall-effect sensors or something even more sophisticated.

As an anonymous poster, with a definite personality problem, no more replies from me......

Do remember that answers here cost nothing, all we ask for are reasonable manners, which are seemingly in very short supply with you.

Bye.