Question about ELCB and RCCB need help!

[Markokk888]

My question is how to tell from the looks if I have old ELCB or a new RCCB ? I know the functionality of the devices but I don’t know how to tell if I have ELCB or RCCB just looking at it. How can I tell which is who ? again i'm asking not about the functionality but how to identify it quickly ?

[Specmaster]

The answer is (provided the ELCB has been made within the last 20 years or so, ones produced before then may have been voltage operated and were often used in areas which had very poor ground earth resistance figures) nothing, zero difference its just a change in terminology. ELCB refers to an Earth Leakage Circuit Breaker. Any current leaking away to earth will cause an imbalance between the live and neutral wires that pass through the toroidal transformer and this will produce a small voltage on the detection coil wound around the toroidal core which will operate a sensitive relay to operate and cause the circuit breaker to trip, disconnecting the supply. This imbalance causes a current to flow in the detection winding, this is called Residual Current, so therefore a RCCB is just the old ELCB brought upto date with the new terminology and is called a Residual Current Circuit Breaker.

Does that help? If you require more info or some diagrams that show how these work, google is your friend.

[Markokk888]

Well thanks for the replay but that doesn't answer my question i know the history and technology that is involved here but the old elcb and the new rccb looks exactly the same how to know if its actually elcb or rccb installed. i cant tell the differences when i see one installed. if its rccb then everything is fine but if there is elcb i want to update it to rccb but i really don't know if its elcb or rccb. the breakers are look exactly the same to me.

[Specmaster]

Then in that case I would bet that they are identical in every sense. I used to sell these for many years and the old earlier ELCB's were much larger than the current ones are. Are we talking commercial or domestic here?

[Markokk888]

Domestic. Basically in use with the apartments or houses. ELCB using a ground connection to detect the voltage leaks.. but it's basically connected through a din rail so you wont able to tell if its old ELCB or newer RCCB type or RCBO. So the problem is if you don't know which type is it you cant upgrade it. it will be stupid to replace RCCB with a new RCCB.. there has to be a way to know the differences just by looking at it. or something like that..

[Specmaster]

That's what I thought and simply, if its DIN rail mounted then it will be the new type of current operated ELCB as the voltage types ceased to be after 1981 and where way to big for DIN rail mounting as can be seen in this video https://www.youtube.com/watch?v=0s7Wqivg0lw&feature=youtu.be

This site will show you the connections to each type, the principles of operation etc https://www.elprocus.com/working-principle-of-earth-leakage-circuit-breaker-elcb/
and if your not sure which type you have then a simple and quick method is to look at the cables going to it. Voltage operated requires 6 cables for a domestic installation and a current operated only requires 4, supply in and supply out (double pole) and all the sensing of any leakage is done internally the device.

In a voltage operated, you need supply in, supply out (double pole) and also 1 cable goes to the main earth stake/point and the other cable goes to the earth terminals on switches, sockets, fuse outlets etc so that it is then connected to the metalwork (exposed framework) the anyone would normally come into contact with in the normal operation of the appliance. These devices can be deadly as they rely on the fault path being live connection to the metal frame work, connected back to the ELCB device via that critical cable between the exposed metal and the frame terminal on the breaker. if this or the other cable to main earth stake is compromised ie. broken the breaker will not disconnect the supply.

[Specmaster]

A voltage operated ELCB is normally labeled as VoELCB and a modern current operated one is either ELCB or RCCB or can be RCD.

VoELCB = Voltage operated Earth Leakage Circuit Breaker No longer in common use, sometimes found in some industrial equipment (very rare)

ELCB = Earth Leakage Circuit Breaker    Very Common type and are the only ones allowed to be used these days.

RCCB = Residual Current Circuit Breaker    Very Common type and are the only ones allowed to be used these days.

RCD = Residual Current Device    Very Common type and are the only ones allowed to be used these days.

[Markokk888]

Thank you for your time

[Specmaster]

No problem.