Quick electrical question

[barossa]

Hi all,

I have a trip switch on my mains ring that keeps tripping only in the last few days.

Everything on that side of the ring has been disconnected, and it is still tripping.

Tried the ring into a different trip switch and this tripped also.

All the power points seem to be dry.

Any ideas of where to look next

cheers

[Smelly]

With everything switched off and the ring unconnected check whether there's a circuit between the hull and live/neutral. It sounds like there probably will be and a short's developed somewhere. Then it's just a case of finding it.

[chris w]

Hi all,

I have a trip switch on my mains ring that keeps tripping only in the last few days.

Everything on that side of the ring has been disconnected, and it is still tripping.

Tried the ring into a different trip switch and this tripped also.

All the power points seem to be dry.

Any ideas of where to look next

cheers

Do you know if it is a miniature circuit breaker (MCB) that is tripping or the Residual Current Detector (RCD) that is tripping? These are tripped by different faults. The MCB is tripped by an overcurrent fault, ie: a short between live and neutral that exceeds the current rating of the MCB (eg: 16A)). The RCD is tripped by a short between live and earth and will trip at about 30 mA (30/1000ths of an amp).

It's easier to fault find if we know which it is.

 

Chris

[barossa]

Do you know if it is a miniature circuit breaker (MCB) that is tripping or the Residual Current Detector (RCD) that is tripping? These are tripped by different faults. The MCB is tripped by an overcurrent fault, ie: a short between live and neutral that exceeds the current rating of the MCB (eg: 16A)). The RCD is tripped by a short between live and earth and will trip at about 30 mA (30/1000ths of an amp).

It's easier to fault find if we know which it is.

 

Chris

It is one of the MCB that is tripping

cheers

[GUMPY]

It is one of the MCB that is tripping

cheers

How old is it?

I do find at work that MCB that have been used near their limit a lot tend to malfunction after a while and trip for no reason.

[barossa]

How old is it?

I do find at work that MCB that have been used near their limit a lot tend to malfunction after a while and trip for no reason.

its aprox 3 months old

[Nickhlx]

its aprox 3 months old

 

 

An RCD could also trip with a neutral to earth fault.....

 

Nick

[kayDee]

Hi

You could disconnect the ring at its furthest socket (and in the consumer unit) - giving you two radial circuits and then see which one still keeps tripping. This will tell you which side of the (old) ring was the problem. Once you have isolated a particular side of the (old) ring - you'd have to start checking sockets and cable runs on that particular stretch of cable.

Its somewhere to start anyway... You'd need to meter out one cable from the other one to ensure you had the correct side connected into the MCB and the furthest socket. The other cable needs to be isolated while you're working on it even though it SHOULDN'T theoretically be live!

 

REMEMBER TO ISOLATE ANY BARE RING CABLE THAT YOU'RE NOT TESTING (WHERE YOU DISCONNECTED THE RING AND IN THE CONSUMER UNIT) AND MAKE SURE THE OTHER CABLE IS CONNECTED TO THE SOCKET (AS THE SOCKET MAY BE THE PROBLEM!)

Kay

x

Edited March 27, 2009 by kayDee

[chris w]

It is one of the MCB that is tripping

cheers

Check behind each socket for a frayed or disconnected wire. If it is tripping an MCB with nothing plugged into any of the sockets, then either a live or neutral wire has come out and is touching the other main conductor or the mains cable has frayed somewhere and the same is happening. Check any connection blocks en route. The fact that it is an MCB not an RCD that is tripping will make the fault easier to find. RCD faults are often a b*gger to find.

 

As someone else suggested, it could be the MCB itself at fault and a simple substitution will prove or disprove that eventuality.

 

Chris

Edited March 27, 2009 by chris w

[barossa]

Check behind each socket for a frayed or disconnected wire. If it is tripping an MCB with nothing plugged into any of the sockets, then either a live or neutral wire has come out and is touching the other main conductor or the mains cable has frayed somewhere and the same is happening. Check any connection blocks en route. The fact that it is an MCB not an RCD that is tripping will make the fault easier to find. RCD faults are often a b*gger to find.

 

As someone else suggested, it could be the MCB itself at fault and a simple substitution will prove or disprove that eventuality.

 

Chris

THANKS TO YOU ALL

THOSE IDEAS ARE A GREAT HELP CHEERS FOR NOW