Cable leaving house to underground.

[hard-work]

Just a quickie. A cable connected to a house ring, it leaves the ring as a spur, using armoured cable, then goes underground to a shed or garage.

1. Does any cable, as it leaves a house, need additional fuse protection at that point - is there a reg stating so?
2. Is the mcb/rcbo at the CU good enough?

thx

 

[chivers67]

It will be protected by the Fuse inside the house but without knowing the Conductor size I can't give you reassurance it will be adequate.

Ideally the Armour will be Earthed & it should have an RCD or RCBO protecting it too. (Edit - Meant what's on the end of the Armour rather than the Armour itself)

 

[hard-work]

2.5mm ring, 2.5mm armoured cable to outside.

 

[EFLImpudence]

1. All cables must have fuse (etc.) protection.
2. If the cable is good enough.

It is preferable NOT to have an RCD for SWA.

 

[hard-work]

My prime question is:
Does any cable spurred off a ring, as it leaves a house, need fuse protection - is there a reg stating so?

 

[DetlefSchmitz]

Your question is ambiguous so cannot have an answer. As usual, if you give more detailed information, and ask a more specific question then you may get a definitive answer. This secrecy does not help communication.

 

[hard-work]

The question is very clear indeed, with no ambiguity whatsoever. I itemised it into two in the first post. I put in into numbers for ease of reading as I know I may get a whole lot of noise coming back. I reiterated the question, clarifying it even more. I cannot be more clear.

 

[DetlefSchmitz]

Up to you - just trying to be helpful.

 

[hard-work]

If you cannot understand a very clear question, I cannot help you. Unfortunately yours is one of the types of posts I regard as noise. So, if you cannot answer just butt out - simple.

 

[EFLImpudence]

In that case, I answered you questions - even wrote 1 and 2.

 

[bernardgreen]

If you are happy for a fault in the shed / garage to prevent you from using power from the sockets on the ring then no need for anything. It would be sensible to have a double pole isolator between the ring and SWA

If the ring is supplied from a 32 Amp MCB then would the 2.5 mm² cable have adequate protection. From CCU to SWA is 5mm² ( 2 x 2,5 mm² in parallel )

 

[winston1]

My prime question is:
Does any cable spurred off a ring, as it leaves a house, need fuse protection - is there a reg stating so?

It will be protected by the 32A MCB that protects the ring. But note the normal rules for a spur apply. It can only feed one single or double socket or one FCU.

 

[hard-work]

In that case, I answered you questions - even wrote 1 and 2.

You wrote:

1. All cables must have fuse (etc.) protection.
2. If the cable is good enough.

It is preferable NOT to have an RCD for SWA.​

No. 1, did not answer the question of fuse protection as the cable leaves the house. We all know all cable need fuse protection, so the answer was worthless.
No. 2 answered nothing at all relating to the question.

What I asked was very simple to understand.

 

[chivers67]

My prime question is:
Does any cable spurred off a ring, as it leaves a house, need fuse protection - is there a reg stating so?

Is it longer than 3M?

Reg 433.2.2 The Device protecting a Conductor against overload may be installed along the Run of that conductor if the part of the Run between the point where a change occurs

My prime question is:
Does any cable spurred off a ring, as it leaves a house, need fuse protection - is there a reg stating so?

Covered in 433.2.2 . As the circuit has altered in Method of installation if it is longer than 3m I think I'd be more comfortable if it had a DP Switchable FCU where it spurs off the Ring but then again it depends on what it's terminated into and what is supplying.

 

[hard-work]

It will be protected by the 32A MCB that protects the ring. But note the normal rules for a spur apply. It can only feed one single or double socket or one FCU.

Thanks. Good we are getting somewhere
So the cable does not need fuse protection as it leaves the house to dive under the ground. Of course it cannot have more than one socket off spur. If the cable runs say into a garage, the garage CU will take care of all inside. As there will be a main fuse/mcb in the garage, it can be split into sub circuits after - sockets, lights.