Plug in MCB upgrade

[JohnW2]

My present set up has a RCCB (i think that's what it is) .... Black box with red test button & sliding off/ on switch. This is between the meter & the fuse box.

As has been said, we could do with a photo, so as to be sure what it is. This could be important - see below.

There is also, before the meter, another black box with a seal on it but no switches - what would this be for?

I imagine you're referring to the housing for the electricity company's ("DNO's") fuse. Again, if you want a definitive answer, include this in a photo!

Also, what extra protection would a new circuit breaker unit give me over staying with the existing box fitted with or without plug in mcb's

If the 'black box' is a modern-type ('current-operated') 'RCD', then a new CU would give you no additional protection - merely added 'convenience' in that it would contain more than one RCD, so that one fault resulting in a trip would not 'take out' your house's entire electricity supply. If the black box is not an RCD but, rather, an old-fashioned Voltage-Operated Earth Leakage Breaker (VOELB), you ought to arrange to get it changed for a proper RCD as a matter of some urgency (if you don't decide to get a new CU), since VOELBs are no longer acceptable, and do not provide adequate protection (which is why we need a photo!). I'm a bit suspicious since, whilst VOELBs were often black, it's rare to see black modern RCDs.

Kind Regards, John

 

[JohnD]

I'm thinking Henley.

 

[sparkwright]

In agreement with what John has said above.

Electrically, just replacing the fuses with circuit breakers isn't much of an improvement at all. The only main advantage is you don't need to change fuse wire when resetting.

If the black box is a VOELB, this ought to be replaced for an RCD (RCCB).

HOWEVER, if it is an RCD (RCCB), or gets replaced for one, this still is far from ideal. The reason being, if one fault in the house cuts out the RCCB, then nothing in the house will work.

A modern consumer unit is divided into two or more RCDs, so you won't lose all the power.

You could, however, have RCBOs instead of circuit breakers in your NEW consumer unit. RCBOs are a combination of both an RCD and an MCB (circuit breaker).

I should point out, RCDs nowadays usually have to be 30 mA. It may be that the black box, if it is an RCCB, is 100 mA - which probably would have been ok at the time.

So, without getting too technical, it does sound like your house would benefit from a new consumer unit.

Don't forget the photos, if possible.

 

[JohnW2]

I'm thinking Henley.

I would think that a Henley upstream of the meter would be extremely unusual, and quite a temptation to those who might be attracted by the idea of free electricity!

Kind Regards, John

 

[sparkwright]

Good point.

Islandman, a Henley is an unofficial name for a junction box used for joining meter cables (or tails) together. There will be no switches/breakers on a Henley/Isco block.

EDITED for spelling.

 

[JohnD]

I got the impression it was downstream of the meter

"before the meter" depends where you are starting from. The photos will tell us.

 

[JohnW2]

Good point. Islandman, a Henley is an official name for a junction box used for joining meter cables (or tails) together....

I'm not sure I would describe it as 'an official name' - I would say that it's more a case of 'sloppy electrician-speak'!! As you know, Henley was the brand of what was once the main (or only) 'service connector block'. Although few, if any, such blocks are made by Henley any more, many electricians continue to call them that!

... a bit like 'hoover' and 'biro', I suppose!

Kind Regards, John

 

[sparkwright]

Good point. Islandman, a Henley is an official name for a junction box used for joining meter cables (or tails) together....

I'm not sure I would describe it as 'an official name' - I would say that it's more a case of 'sloppy electrician-speak'!! As you know, Henley was the brand of what once once the main (or only) 'service connector block'. Although few, if any, such blocks are made by Henley any more, many electricians continue to call them that!

... a bit like 'hoover' and 'biro', I suppose!

Kind Regards, John

Just corrected that before I read your post. An offical sounds a bit like unofficial!

 

[islandman]

Right, had a close look with a torch & i'm afraid the thing is a VOELB! It's written across the top!

I think i'll speak to my sparks tomorrow to get this sorted asap!

Thanks for clarifying this

 

[JohnW2]

Just corrected that before I read your post. An offical sounds a bit like unofficial!

Or "An official", even

Kind Regards, John

 

[islandman]

Will also get some pics!

 

[JohnW2]

Right, had a close look with a torch & i'm afraid the thing is a VOELB! It's written across the top! I think i'll speak to my sparks tomorrow to get this sorted asap!

Indeed - but this is where you need to make a decision, presumably in consultation with your electrician. There obviously would be no real point in getting the VOELB changed for an RCD if you were soon to replace the CU with a modern one.

Do you know what sort of earthing system you have - one provided by the electricity supplier or one connected to an 'earth rod' in the ground outside your house?

Kind Regards, John

 

[sparkwright]

It sounds like you may be getting a new consumer unit (fuse box).

To have ALL RCBOs is the best you can have, though it will be more expensive. But it will leave you and your wife in a more comfortable position if a fault occurs, as only one individual circuit will trip.

Your electrician may or may not go through this with you, so I'm telling you now, so you're ready.

Also, when replacing a consumer unit with one with RCDs, some old, undetected faults on the house wiring can occasionally be discovered.

It's preferable to test the wiring of each circuit before fitting the new consumer unit. You may like to mention this to him as well.

 

[JohnD]

RCBOs are great

 

[islandman]

JohnW2........... I think this is going from ok, to not so ok & now to worse!

There is an earthing 'rod' in the corner (nearest the house) in our attached garage/workshop. I suspect you are going to tell me this is not good................but it does have a 'hat' on the top,......if that helps!