Why is my MCB buzzing?

[spxy]

Hi all.Any one good with mains problems.
About 6 months ago I changed from a fuse holder to a circuit breaker on my consumer unit on the mains line that feeds all my power sockets in the house. Just recently (or maybe I've just noticed) the circuit breaker has started buzzing loudly when heavy duty items such as my tumble dryer are turned on.
I took it out and found that if you shake it it rattles a bit inside, or if you hold it while on the, buzzing stops .
Is this normal or is the thing broken .
Or could it be too much power going through, its rated at 30 amps , do i need more?
All the sockets in the house 18 in all are connected to this MCB.Is this too many?
The cooker is seperate and so is the shower.

 

[BR]

Is the MCB bussing internally or on the connection at either the top or bottom? The connections to the MCB must be made as tight as possible with a large screwdriver (without overdoing it)

More likely the fault is inside the breaker in which case it needs to be replaced with an identical model (should be 32A Type B)

The number of 13A sockets on the ring is irrelevant, Provided the total floor area is under 100msq (I presume these sockets are on a ring) You should have two cable entering the top of the MCB.

Or could it be too much power going through, its rated at 30 amps , do i need more?

The MCB is designed to prevent more than 32A flowing at any time, should this happen it will trip. So this comment doesn’t make sense and indeed it would be dangerous to install a larger breaker.

It is in my opinion bad practice to install all the sockets on one breaker like this and perhaps something you should have looked at in the future. In modern houses I generally install a minimum of four. (kitchen,utility,sitting room,rest of house)

If it's a new MCB it should be covered under warranty.
This isn't an MCB which plugs into the fuse holder it it? If it is then the fuse holder may be damaged or for some other reason the plug in MCB may not be fitting properly.

 

[securespark]

He says 30A mcb, so sounds like elderly unit......

 

[spxy]

It is a MCB that fits into the fuse holder.Its a Wylex consumer unit.
All the screws are tight in the consumer unit and the MCB is a tight in the socket.Do you think its rattling against the holder then.
So why does it rattles only when my tumble drier or washing machine is on , not anything else?

 

[plugwash]

where did you get this mcb

is it a 30A with push buttons or a more recent 32A with an operating lever

my guess is the buzzing is the mcb running close to its trip point but thier being not enough current to actually cause a trip before the load disapears and the mcb starts to cool down again

 

[Richardp]

maybe its an MCBEE te he!!

 

[spxy]

I got it from B&Q.They designed to fit in the fuses holder and have a lever switch on them.I say its 30 because thats number is on the plug by itself I assume that means amps but I no longer have the packageing.
Its colour coded red.
I've put a fuse plug back in for now and have no problems with it.
If its possible its a faulty MCB I will get another one .

 

[plugwash]

30A or 32A doesn't make much real differnce anyway

as i said the most likely expanation is you are slowly heating it up towards a thermal trip but the overload is dissapearing before it gets hot enough to trip

 

[BR]

the most likely expanation is you are slowly heating it up towards a thermal trip but the overload is dissapearing before it gets hot enough to trip

Quite possibly the problem if the breaker is buzzing internally but it should not be "buzzing" If this is the case the breaker needs replacing