when is a ring main not a ring main

[BoudinC]

hi guys and gals,
I'm in the process of renovating my kitchen and had a quick look at the sockets with a view to changing the faceplates.

There are 6 double and 2 single sockets, but none of them are served by twin cables I would expect in a ring main, I.e. A serial connection or daisy chain of sockets.

what the Dickens is going on and how do I fix it!

any help appreciated

 

[Taylortwocities]

If it is a ring FINAL, there would be two cables at each socket.

Even a radial would have two cables at most sockets, except for the last one.
I would guess that the sockets are actually spurs from a circuit. Could be a ring, could be a radial. There may be a big JB somewhere. Or lots of individual ones hidden under the floor above.
Our friends the kitchen fitters have been known to do all sorts of stupid things.
Like this

Untitled

• Taylortwocities
• 27 Oct 2011

You would need to trace a cable or two to see where they go.

First job. Look at the MCB/fuse for the kitchen sockets, tell us what value the MCB is. That may be a clue...

 

[BoudinC]

hiya, the MCB fuse is 30amp.

 

[Taylortwocities]

Well it is either a fuse or an MCB!
I guess you have the old style rewire able fuses?
if it is 30A then it is probably a ring final, would need to see inside the fuse board and do some tests to be sure.

As I said, you would need to trace the cables to find out what is going on.

 

[BoudinC]

sorry old fashioned layman here! It's a 30amp RCCB. Looking forward to spending some time in my crawl space!

 

[deadshort]

I would think so! If it's a refit i would rewire the kitchen.

Regards,

DS

 

[JohnW2]

sorry old fashioned layman here! It's a 30amp RCCB.

Is that what it's labelled (are you sure the device in question does not say 30 mA?). Exactly what is written on it? Does it have a test button?

Kind Regards, John

 

[BoudinC]

it's a Crabtree C50 RCCB with a test button. Just marked up 30!

 

[deadshort]

If you do not have an electric cooker , i would not be surprised to discover that all your sockets are connected to an old cooker circuit That's a bodge it, dodge it trick !

If you can safely remove the cover of the rccb and take a pic that would perhaps help us work it out.

 

[BoudinC]

cooker is on a separate 30 circuit with isolator switch.

I'll have a look under the floor to trace wiring and advise in due course.

 

[JohnW2]

If you can safely remove the cover of the rccb and take a pic that would perhaps help us work it out.

I'm getting a bit confused here. Is this device a C50 RCBO? If so, all sorts of things would seem to be wrong!

Kind Regards, John

 

[deadshort]

If your C50 RCCB has a BS 4293 number this does not provide over current protection and is an RCD (earth leakage protection only). If that's the case you have dangerous situation which needs urgent attention.

Sorry.

DS

 

[JohnW2]

If your C50 RCCB has a BS 4293 number this does not provide over current protection and is an RCD (earth leakage protection only). If that's the case you have dangerous situation which needs urgent attention.

That's why I said I was getting confused - if it were just an RCD/RCCB (as you say, providing no over-current protection) and not an RCBO, then what would "C50" mean? It sounds like a C50 (50A, Type C) RCBO installed for a shower circuit!

Kind Regards, John

 

[EFLImpudence]

OP has since written:

cooker is on a separate 30 circuit with isolator switch.

 

[JohnW2]

OP has since written:

cooker is on a separate 30 circuit with isolator switch.

I know - and, anyway, a 50A OPD would be rather OTT for a cooker circuit. That's why I suggested that maybe it's a C50 RCBO installed for shower.

Kind Regards, John