3 core armoured cable to meter tails

[akis_t]

Hello,

There is a 3 core underground armoured cable that emerges into a small "plant" room and from there it will connect to the consumer unit which is a fair distance and inside the property. A previous electrician (left when coronavirus) has already run meter tails between plant room and consumer unit (through the loft space) I suppose about 6 metres.

Another electrician that visited recently, does not like the meter tails and instead wants to run the armoured cable all the way to the consumer box, which means some considerable extra effort to run it into the loft space and down.

Is there a way to make use of the existing meter tails which are already installed, perhaps by adding some sort of protective device between armoured cable and meter tails?

 

[Strima]

What protective device is on the other end of the armoured cable?

Are the meter tails buried in the wall <50mm below the finished surface?

Do the meter tails pass through a special location, such as a bathroom?

Are the meter tails at risk of any mechanical and/or rodent damage?

Without seeing the installation it's hard to say why it wasn't all done in SWA...

 

[akis_t]

What protective device is on the other end of the armoured cable?

Are the meter tails buried in the wall <50mm below the finished surface?

Do the meter tails pass through a special location, such as a bathroom?

Are the meter tails at risk of any mechanical and/or rodent damage?

Without seeing the installation it's hard to say why it wasn't all done in SWA...

UKPN cutout and fuse and the electricity meter at the other end.

Meter tails go through the loft and are not buried anywhere.

Potentially the meter tails could be disturbed by someone working in the plant room or inside the loft.

We have not fitted the armoured cable yet.

 

[westward10]

I see no problem with "tails" so long as they are suitably installed. What circuit protection are you putting in for the tails at the intake.

 

[akis_t]

I see no problem with "tails" so long as they are suitably installed. What circuit protection are you putting in for the tails at the intake.

Ah this is what I was asking for help on, what protection do we need to place between armoured cable and tails? What circuit protection are we allowed to place?

 

[Strima]

Without knowing the load and intended use of the circuit it's hard to say. Is this domestic/commercial???

 

[akis_t]

Without knowing the load and intended use of the circuit it's hard to say. Is this domestic/commercial???

It is a small annexe with one electric oven and not envisaging any other serious loads. The cutout fuse will be 60A. Maybe in the distant future they give me 100A. After the cutout the electricity meter and then 40m of armoured underground cable. The armoured cable will then connect to the long meter tails to power the consumer board. I presume we need something between armoured cable and meter tails, I presume an RCD of some kind, in case someone decides to cut through the tails?

 

[Strima]

The SWA will not need RCD protection, possibly the tails won't require it but without looking at it I can't say.

A switched fuse between the meter and SWA will be required, a fuse rating of around 40 amps would probably suffice depending on loads in the annex.

What heaving loads are there such as shower, water heater, heating systems?

 

[akis_t]

The SWA will not need RCD protection, possibly the tails won't require it but without looking at it I can't say.

A switched fuse between the meter and SWA will be required, a fuse rating of around 40 amps would probably suffice depending on loads in the annex.

What heaving loads are there such as shower, water heater, heating systems?

I understand the armoured cable does not need an RCD.

I would have thought that the long tails might do though as someone (or something) might cut through one?

The only heavy load I am envisaging is the electric oven 3.2KW, kettle 3KW and maybe the NEspresso coffee maker.

 

[Midwest]

Personally I would prefer the completion of the swa cable to be swa cable. How long a run is this part of the circuit?

I've run some sheathed & insulated tails of about 3m surface in trunking. But I've also seen them run for some distance in joists (more than 50mm etc) or up in loft spaces, but I've never been comfortable with that.

 

[ChrisElectrical88]

Personally I would prefer the completion of the swa cable to be swa cable. How long a run is this part of the circuit?

I've run some sheathed & insulated tails of about 3m surface in trunking. But I've also seen them run for some distance in joists (more than 50mm etc) or up in loft spaces, but I've never been comfortable with that.

Agreed, why not just run the SWA the distance? Clip it higher up in the loft so you don’t need any tight radius bends and flop in down in the room where the CU is.