Supply to a garden hut

[Bul]

I have an armour cable out to a garden hut and used a RCD 2 way consumer unit.

The supply comes from an MCB in the consumer unit into a rcd/spur and out on the armour cable.

There are 2 rcds I know. Would you use a fused spur on its own to protect the armour cable (instead of the rcd/spur) and would a standard fuse provide discrimination to avoid nuisance tripping?

As always comments appreciated.

 

[johnboy6083]

i wouldnt neccesarly use an FCU. i would joint it an thats it. no need to introduce more protective devices into the circuit that are not needed. Also the MCB would react long before the fuse thought about it IMO. This is assuming of course that the supply cable to the SWA doesnt require RCD protection, and that you will provide RCD protection to the final circuits at the other end, if its needed.

 

[Dave 85]

Why use anything? Its protected by an MCB, thats all you need on the SWA as far as I'm aware

 

[wallyanker]

I wouldnt use an rcd fcu at the origin, the mcb is adequate protection for the supply swa to the hut. RCD board in the hut is a yes.

 

[johnboy6083]

does the cable from the MCB to the SWA require RCD protection, ie buried less than 50mm, no steel protection?

 

[wallyanker]

Depending on where the CU is situated, the swa could be glanded to the CU itself and then fed straight to the hut, dependant on CU brand, type, location, etc..

 

[johnboy6083]

im assuming that as he has mentnioned using a spur, then this isnt possible.

 

[Bul]

No, the metal box of the spur /rcd was used as a way to terminate the armour. The spur is next to the CU.

 

[wallyanker]

Is the cable surface mounted from CU to FCU?

 

[johnboy6083]

Then do away with the spur, just use the box as a JB, and feed it straight from the MCB. Provide RCD protection in the summer but for final circuits.

 

[nickblake]

what size is the armoured cable

 

[Bul]

The cable is surface.

 

[Bul]

The armour is 6mm.

 

[Bul]

Guys
I'm getting it now that i can use the spur box as a junction box.

Many thanks !

 

[johnboy6083]

Don't forget to earth your SWA.