Neutral Wire Connection and ELCB Tripping

I'm with you on that John! The ELCB is being unbalanced so shift that neutral to the same side as the phases before the ELCB in box 1!

I would also suggest putting an ELCB and an RCD in box 1 on the new line to give it some protection! Is that a simple isolator switch in Box 1 if so, the new line needs protection against accidental damage on route to the new board which an isolator switch won't offer!

Thanks everybody, your advice helps.

I like to ask another question, the neutral line connected to the ELCB1 is directly from the service meter. will it be risk of electrical shock when i do the connection there?

another question is to Mr Truman, isn't that the ELCB and RCD having the same function; to cut of the circuit whenever there is differencial current detected? Why need to have both ELCB and RCD? Please enlighten me, thanks :), and where should i add in the RCD if really needed.

Is there a distance contraints for the ELCB/RCD to work properly? as mentioned, my secondary box is 60 meter away from main box.

Hi all

What is RCD.I think it is used in LT circuits.

regards

gova

You really need to check out your local regulations for both your safety and electrical conformity! They may state that only a qualified Electrician can modify or install electrical circuitry in your area!

Not knowing where you are or you local terminology, I would hazard a guess (only a guess) that your ELCB is an overcurrent/thermal overload circuit breaker (I may be wrong, does it have a test button?) An RCD is a residual current device which detects differences in current between the neutral and the phases! This can also detect ground leaks and line faults! Used on LV stuff (LV being 50V to 1000V)

If in any doubt at all, don't play with it! Get a certified professional to do the connection! And yes, the neutral may hold some dangerous current which could kill you! Be safe, get the pros in!

ELCB Earth Leakage Circuit Breaker or Earth Leakage Core Balance.

RCD Residual Current Device (another way of saying Earth leakage core balance).

What can confuse the issue is some units are core balance only and others are a combined MCB ELCB (Magnetic and/ or thermal overcurrent combined with ELCB). Whenever I install these units I read the supplier details carefully and look at the tiny diagram on the device. If an ELCB (RCD) only is installed overcurrent protection will need to be supplied seperately.

GA

GA from me and a fully correct answer......

It amazes me that so few people "really" understand electricity......but they play around and connect to it! The diagram "SHOUTS" the problem out loud for ANYONE with a minimum of intelligence and knowledge!!!

No wonder the "Darwin Awards" site has so many dead Stars!!!

Andy,

You got it in one. So many amatuers not only do it wrong but stand and defend their actions like an over unity clown.

Right on!!

there is no need for the insulator for the second elcb. just remove it and see

Hi Piggy,

As already stated the N needs to be connected at the same place as the phases.

RCD = Residual current device = Earth Leakage Circuit Breaker= ELCB.

However, Mr Truman's comment about the isolator needing to be an overcurrent device (MCB)to protect the cable to your second site (garage/workshop?) is very valid. I would suppose it is from the way you have drawn it, but make sure it is sized correctly.

regards

Chas.

OK, now ELCB makes sense! I had it in my head that it was something else! (Too long in Spain!) But you still want protection on that line! At the moment it has none! Bad move and highly dangerous! It needs overload protection and why not put the new circuit in the DB of box 1 that way it uses the ELCB of that board?

Thanks everyone for good advice, and Mr Truman's suggestion is very useful, i will, might as well use the ELCB at box1 to protect the long cable

and... the ELCB came with test button...

Hi Piggy,

You need to protect the cable to board nº2 with an MCB not an ELCB.

Although you can protect the whole installation with one ELCB you might regret it if you get any leakage. By using two individual ELCBs, one in each board, you still have the same protection but you have the convenience of being able to reset it locally and so find the fault much easier/quicker

Chas

Hi Capblanc,

I have done the installation today, the 3 phases and neutral went through the ELCB in box1 and it works fine. at the end of 60 meter cable, i added a main swith with fuses and ELCB.

Box1 was installed by pros contractor, so I will not modify its content.

thanks...

Piggy, Is the cable protected for overcurrent?

Chas

Hi,

this cable only protected with ELCB. But downstream each equipment, power socket, light points and etc being used are with MCB installed.

thanks....

The problem there is that your cable run from box 1 to box 2 is not protected - a fault could lead to a fire. Please, for your own safety, fit overcurrent protection for the cable at the box 1 end.

GA from me.

It does look as though he does not have a clue, even with several people actually telling him what is wrong.....he should nget a Darwin Award.....

Let's also hope that his tails are of big enough csa to take the increase in load, also his ELCB is rated to take the new increase in load and he has connected the new cable in an MCB in box 1 after the ELCB and is rated for the new load! Not to mention checking to see if his electrical supply line is rated to take the new load! Who knows, it might be one of the old 3*25/1*54 Al lines! We can only hope that nothing goes wrong and all the above are in a good working state! I still think it would be in his best interests to get a pro in to check it out!

I suspect that your installation now looks like this:-

The second ELCB does nothing that the first one already does.....and it will be a guessing game as to which one trips first if they are of the same type and size!!!

Totally pointless.

What you should have, assuming that you have over current protection in either the isolator or the ELCB (that is a must!) is this:-

Or you should have fuses where L1, L2 and L3 are shown!!

Lets hope not Andy, In your 2nd drawing, the new line has only the protection of the main fuses and they could be anything up to a couple of hundred amps! Enough to fry anybody that comes into contact with the conductor! That new line needs protecting with an MCB and some form of RCD/ELCB otherwise you might as well tell him to climb up the pole and hang on for dear life! That 2nd drawing is just plain dangerous!

I thought I mentioned all that, did you only look at the diagram and not read (or not understand) my comments!!!

Hello Andy,

Indeed, I looked at you drawing, read your comments and even understood what you were implying! But I'm sorry, I still have to disagree with you! I will give you my reasons as follows:-

1. In your drawing, your connection is before any circuit protective device. You say that it should have fuses at L1, L2, L3 (Valid point, Agreed) but if this new line is just a plain cable which is just thrown on the floor or draped over rafters or is placed where it could get damaged, then the fuses will not offer the protection needed! Think of a cable getting a spike through it! Maybe not enough current to blow the fuse but enough current to cause injury or death when they pull out the spike! If the new installation was installed underground with concrete on top with protection against accidental damage, then maybe this is an acceptable approach but we can't assume this is the case.

2. 'What you should have, assuming that you have over current protection in either the isolator or the ELCB (that is a must!) is this:-' This is fine as long as the new cable run is connected after the protective devices which in your drawing they are not. The overcurrent protection and the ELCB is only protecting the cables after the protective devices and not before!

3. We have to assume that the OP has no knowledge what-so-ever when it comes to electricity. Therefore, any advise given must assume that the new cable will not be installed with the same care as if it was installed by you or I! We need to cover all scenarios including the OP using an old 4 core extension lead running through his workshop and out under his metal garage door, across the garden and into his shed!

Andy, I hope you understand what I'm getting at and don't take it personally!

OK, you are looking at in a way that nobody has really defined up to now - how long the cables are and whether they are correctly installed or just draped over the landscape....

I was more concerned at this point with getting the right hardware done and would have left distances and methods of installing as a future (very important) point(s) to be covered, but I have no problems with dealing with them now either....

I am afraid that the original post understand so little with regard to principles and safety, that I was trying to take him "slowly to the well to drink!"

But if you feel firmly that he should be brought to that point quicker, well I cannot see any problems with that!!

Have a great day and thanks for your interest.

Andy,

It's always better to see all sides of the equation. For a professional installation, you were totally correct in your set-up and I value the input you provided on this topic, and hopefully the OP will too. Anyway, I hope we meet on another thread, so take it easy Bud and keep up the quality work!

Best wishes

(Another) Andy

Good name!!

I think it's best that he gets a pro in otherwise he will be so confused by all the stuff we have told him! I for one, am washing my hands of this thread for his own safety and for the safety of any other readers of this thread!

the problem is in your neutral tapping. If it is tapped before the ELCB in the main distribution box then it will function fine