Changing Consumer Unit

[DangerToDIY]

I posted a while ago regarding my dodgy old wylex metal enlosure CU here [url]//www.diynot.com/forums/viewtopic.php?t=12138 [/url]

I am now finally about to change it but the REC arent willing to move my incomer. This means I only have 240mm between the wall and the side of the incomer. I cant move down or up with the CU because the 6mm t+e will not budge in the conduit and I dont have the money for a full rewire.

I intended on buying a spit load metal enclosdure cu from MK but the narrowest one is about 380mm wide. Too wide.

Could i fit a standard CU (ie not split load) and still have a safe installation? the k5508 from MK will fit snugly.

What do you guys recommend?

Can I still earth the enclosure as you see in the previous post, but replace the galv strap with 16mm earth cable?[/url]

 

[ban-all-sheds]

I posted a while ago regarding my dodgy old wylex metal enlosure CU here [url]//www.diynot.com/forums/viewtopic.php?t=12138 [/url]

I am now finally about to change it but the REC arent willing to move my incomer. This means I only have 240mm between the wall and the side of the incomer. I cant move down or up with the CU because the 6mm t+e will not budge in the conduit and I dont have the money for a full rewire.

That's unfortunate, because you do need at least some rewiring - you've got no earths on your lighting circuit for example. That implies an overall installation age where an inspection is warranted.

The reason that 6mm won't budge is why we commented before that it shouldn't be in conduit - it's too tight a fit, which means that it can't dissipate heat the way that it is expected to and could therefore overheat and become damaged and unsafe.

I intended on buying a spit load metal enclosdure cu from MK but the narrowest one is about 380mm wide. Too wide.

Could i fit a standard CU (ie not split load) and still have a safe installation? the k5508 from MK will fit snugly.

You'd have to have your entire house on RCD, which you will come to regard as inconvenient.

What do you guys recommend?

Doing it properly - sorry.

 

[plugwash]

one option is use of a switch only CU and using rcbos for the rings

this avoids the problem of putting the whole house on rcd but rcbos do cost a bit

 

[DangerToDIY]

Ok, looks like I am going to have to find some more cash.

We are already going to rewire the lights and my friend who is a spark said we can run 1.5mm in singles in the conduit for the lights and it would be up to regs. Is he right? It would be so much easier than trying to get t+e around the bends

We are definitely going to rewire the kitchen too, so I guess I might as well go the whole hog.

This still doesnt help me as far as the space for the cu goes because the rec wont move the incomer - so what can i do?

If i was to use rcbo's would I use the same rating as if they were mcb's?

 

[dingbat]

We are already going to rewire the lights and my friend who is a spark said we can run 1.5mm in singles in the conduit for the lights and it would be up to regs. Is he right?

Yes

If i was to use rcbo's would I use the same rating as if they were mcb's?

Yes. a RCBO is a residual current circuit breaker with combined overload protection - in other words a combined RCD/MCB

 

[ban-all-sheds]

If you have the services of a sparky available, can't he just put in some longer tails so that you can put the CU somewhere with more space?

 

[DangerToDIY]

My sparky mate lives too far away to help out. What is the longest you can safely make the tails? What are the regs with regards to routing and protecting the tails?

 

[ban-all-sheds]

The acceptable length limit varies from DNO to DNO, but it's in the range of 2-3.5m, AFAIK.

The problem is that replacing them involves practices which are not advised for DIYers to attempt, like cutting the seals and pulling the main fuse.

 

[plugwash]

you generally have to do that to replace the CU anyway

 

[DangerToDIY]

i guess i'll call the rec to pull the main fuse.

I have decided to remove some of the wall to get a bigger cu in. Will let you know how it goes.

Thanks for all the help guys, its much appreciated

 

[ban-all-sheds]

you generally have to do that to replace the CU anyway

Sorry - sloppy wording. Yes, in any event you need to pull the fuse, but to replace the tails you need to breach the meter seals as well. At least, you would on my meter.

Guess you could pull the fuse and insert a Henley block - seems a bit tacky though if you're extending rather than splitting.

 

[plugwash]

at least the meters i have seen the terminal seals are totally seperate from the body seal (which you would need to open to tweak the meter)

if you really wanted to steal lecky i still think the foolproof way would be to resin joint the service cable
(note: while i think this would be the most effective way remember stealing is illegal and resin jointing live cables requires special training to do safely)

 

[ban-all-sheds]

at least the meters i have seen the terminal seals are totally seperate from the body seal (which you would need to open to tweak the meter)

If you can access the tail terminals you could take a feed off the incoming ones, e.g. just for your new 10.5kW shower. No drop in metered consumption.

if you really wanted to steal lecky i still think the foolproof way would be to resin joint the service cable

Blimey, Plug - you've already been in trouble for telling people to pull service fuses - I dread to think what'll happen now....

 

[plugwash]

If you can access the tail terminals you could take a feed off the incoming ones, e.g. just for your new 10.5kW shower. No drop in metered consumption.

sure you could but it would be easy for them to spot that you had done that

anyway as i have said before they really don't seem to pay attention anymore
the terminal seals on our meter and our service fuse seals have been gone for a few years now since we had our extention built (cu replacement was part of the work done)

with this in mind even if the recs do spot it they are left with no idea who did it and when

 

[securespark]

Have just skimmed thro' quickly.... no one has queried WHY the REC won't move the incomer?