Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

circuit breaker

Status
Not open for further replies.

blibala

New Member
can anyone briefly explain to me what is the difference between MCCB,RCCB,ELCB, ACB and MCB. these circuit breakers confuse me a lot.
thank you
 
MCB - miniture circuit breaker. these are the main switchs for individual circuits an a building. come in different ratings from 6amp

RCD - residual current device. similar to a MCB (as in it trips at a certain rating) but also 'monitors' power flow theu live and neutral. whateva goes thru live must come back - if it doesnt its goin sumwere else (thru a person). if there is a imbalance (stated of RCD - normally 30ma) then itll trip

the otha parts u asked for are similar to these. try searchin altavista.com or summit
 
ACB - Air Circuit Breaker - also breaks on overcurrent, like an MCB, but is usually larger (>200A). Often overload and short circuit current trip values and times are adjustable.

RCD/ELCB - also known in the USA as GFCI (Ground Fault Circuit Interupter)
 
circuit breakers

MCB/Cb: Miniture circuit breakers/Circiut breakers.

Known as circuit breakers. It limits the current flowing through to a circuit.

Ratings can be 5A, 10 A, 15A 20A....etc.

Lets take 10A CB on fuse board at ahouse.

If circuit draws more than 10A, circuit will trip (or break the circuit)

It can happen when you connect so many devices to sockets which is belong to the same circuit.


ELCB/RCCB Earth leakage/ Residual current devices

Known as RCDs. It trips the circuit when there is earth fault current.
Phase(line) and Neutral both wires connected through RCD.

The amount of current flows through the phase(line) should return through neutral . It detects by RCD. any mismatch between two currents flowing through phase and neutral detect bt RCD and trip the circuit within 30Miliseconed.


Fault can happen if some one get electricuted due to electrical fault of an applience.
Then part of current flows through the body of the person to earth.

Mainly CBs are protective devices used to protect peopls as well as machines.

CB can be used to protect circuit from short circuit current and /Or over load current.
 
in the UK, if a house has an earth system connected to an earth rod and not the main incoming cable, then it must have all circuits protected by an RCD (because u mite not be able to get enough fault current to trip a MCB)
 
andrew2022 said:
in the UK, if a house has an earth system connected to an earth rod and not the main incoming cable, then it must have all circuits protected by an RCD (because u mite not be able to get enough fault current to trip a MCB)

There's no requirement in the UK for an RCD, although it might be a requirement on new buildings - no updated regulations apply to old installations.

I don't see the problem with an MCB, it's basically just a resetable fuse, and has nothing to do with any earth lead - so having an earth spike, or not, makes no difference.
 
Nigel Goodwin said:
I don't see the problem with an MCB, it's basically just a resetable fuse, and has nothing to do with any earth lead - so having an earth spike, or not, makes no difference.

No, intrinsically it doesn't relate to earth, but there is much regulation regarding the size of earthing cables - there has to be a low enough resistance in the installation (fault loop impedance) to trip the circuit breaker (or fuse) in case of a short to earth, in the minimum tripping time (which is usually specified as 0.4s)

In Australia, RCDs are a requirement on all new circuits (in both new and existing installations), except hot water and stove circuits.
 
it is now a legal requirement in the uk to have a RCD on all installations with an earth rod. all wring colour codes are also changing
 
andrew2022 said:
it is now a legal requirement in the uk to have a RCD on all installations with an earth rod. all wring colour codes are also changing

Presumably this is on NEW installations, or on serious changes to existing systems? - as far as I'm aware changes don't apply to existing wiring.

What are the proposed colour changes?, sounds interesting!.
 
in single phase supplies red will be brown and black will be blue

in 3 phase red will b brown, yellow will be black, blue will be slate and black will be blue. there is a 2 year changeover period startin jan 2004. by jan 2006 all new installations must use the new colouring system

reasons for this is so we use the same colours as the rest of the world, since if u have an electrical qualification in the uk, it is valid thruout the world

as for changes to existing systems, if u do work on a circuit what does not comply with the regulations then that part must be upgraded (even if u change a socket on a circuit, the rest of that circuit must be to the regs) otherwise other circuits can be left (aslong as they are safe)

as for other changes, everything metal in a bathroom must be earthed by a 4mm cable in a ring connected to the earth in a light (not a shower). there were some more stupid changes but i cant remember some f them
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top