Terminating SWA in knockout box outside a plastic CU

[ban-all-sheds]

First class work.

 

[f0rmula]

can't you just cut a 20 or 25mm hole in the bottom of the CU?

(or am I being dumb???)

There's no flat place to cut it! It's all moulded with knockouts for cable entry. The back is the only flat bit.

Untitled

• f0rmula
• 1 May 2013
• 3

 

[JohnW2]

Wouldn't it be cheaper (particularly if you were going to get a decent brand of outdoor sockets) to have an RCBO in the CU than to fork out for two RCD-protected sockets?

Hi. The CU is in the cellar, so the plan was to put the RCD out where you can reset it quicker if it does trip.

Fair enough, but how often do you expect the RCDs to trip - and, even if/when it happens, how likely is it that simply resetting it will cure the problem? If it were me, I'd probably be asking myself whether that (hopefully) once-in-a-blue-moon possible 'convenience' justified the additional cost.

Kind Regards, John

 

[RF Lighting]

First class work.

 

[dhutch]

can't you just cut a 20 or 25mm hole in the bottom of the CU?

This is what I did on my plastic wylex garage CU, but some now are so curved/moulded there is not flat face at all.

Wouldn't it be cheaper to have an RCBO in the CU than to fork out for two RCD-protected sockets?

I was thinking this, or even, just have it of an MCB in an RCD protected way.

I used a cheap outdoor socket from tlc, and it was cheap, but bloody hell its rough compaired to the MK one at my parents, time will tell how it worked, but I had to shim under the corners as the slightly uneven brickwork distored the box enough it wouldnt go together as theres no scope for that in the seal.

http://www.tlc-direct.co.uk/Products/LB8810.html

If its a plastic CU, why not use a plastic box?
http://www.tlc-direct.co.uk/Products/WK308G.html

Also never really seen what a piranhna nut gets you over bolting to the supplied earth ring, but im not an electrician.


Daniel

 

[JohnW2]

<piccie>

Aren't those cut core lengths a bit mean? It may be an optical illusion, but it looks as if one might struggle to get them all to whatever is going to be joining them together!

Kind Regards, John

 

[JohnW2]

Wouldn't it be cheaper to have an RCBO in the CU than to fork out for two RCD-protected sockets?

I was thinking this, or even, just have it of an MCB in an RCD protected way.

The OP has an 'all RCBO' CU with no RCDs.

Kind Regards, John

 

[sparkybird]

can't you just cut a 20 or 25mm hole in the bottom of the CU?

(or am I being dumb???)

There's no flat place to cut it! It's all moulded with knockouts for cable entry. The back is the only flat bit.

Untitled

• f0rmula
• 1 May 2013
• 3

Sorry - my bad.... not a great design then!!

 

[ban-all-sheds]

The OP has an 'all RCBO' CU with no RCDs.

There's a plain B20 MCB in it - reason says that's what will supply the RCD socket.

 

[ban-all-sheds]

<piccie>

Aren't those cut core lengths a bit mean? It may be an optical illusion, but it looks as if one might struggle to get them all to whatever is going to be joining them together!

Yes, well...

Done. Before re-making when I found I'd not got long enough cores to get into the choc-block OK..

 

[JohnW2]

The OP has an 'all RCBO' CU with no RCDs.

There's a plain B20 MCB in it - reason says that's what will supply the RCD socket.

Indeed. One assumes that is the OP's intention. However, I was pointing out to dhutch that his idea of feeding the RCD sockets from an MCB 'on the RCD side' of the CU is not possible if there is no RCD

I still think that (even taking into account the minor cost of that B20, which would become redundant), it would probably be cheaper to pay for one RCBO and two ordinary (decent brand) oudoor sockets than to buy two (decent brand) outdoor RCD sockets - but maybe I'm wrong.

Kind Regards, John.

 

[JohnW2]

<piccie>

Aren't those cut core lengths a bit mean? It may be an optical illusion, but it looks as if one might struggle to get them all to whatever is going to be joining them together!

Yes, well...

Done. Before re-making when I found I'd not got long enough cores to get into the choc-block OK..

Ah, so maybe I don't need that trip to Specsavers quite yet

Kind Regards, John

 

[dhutch]

The OP has an 'all RCBO' CU with no RCDs.

Yes, hadnt seen that.

 

[f0rmula]

The OP has an 'all RCBO' CU with no RCDs.

There's a plain B20 MCB in it - reason says that's what will supply the RCD socket.

Indeed. One assumes that is the OP's intention. However, I was pointing out to dhutch that his idea of feeding the RCD sockets from an MCB 'on the RCD side' of the CU is not possible if there is no RCD

I still think that (even taking into account the minor cost of that B20, which would become redundant), it would probably be cheaper to pay for one RCBO and two ordinary (decent brand) oudoor sockets than to buy two (decent brand) outdoor RCD sockets - but maybe I'm wrong.

Kind Regards, John.

When I explained the idea of having "that switch" at the socket rather than in the cellar to my GF, she was all over it. So, given that, and the fact an RCBO would take a week to get here (I want to do it this weekend), I'll recognise you're probably technically correct, but leave as is. Thanks for the advice though. If I ever have to do this again, I'll maybe do it differently

 

[JohnW2]

When I explained the idea of having "that switch" at the socket rather than in the cellar to my GF, she was all over it. So, given that, and the fact an RCBO would take a week to get here (I want to do it this weekend), I'll recognise you're probably technically correct, but leave as is. Thanks for the advice though. If I ever have to do this again, I'll maybe do it differently

Fair enough. I can see nothing wrong, electrically, with what you propose - it's only really a matter of possibly saving a few pounds.

Kind Regards, John