Does armoured cable to Garage need to be buried?

[JohnW2]

Yes, maybe, but a metal sheath provides no mechanical protection and as you have said neither really does the so-called armour.

Exactly my point - yet again we appear to have a reg which makes no real sense!

Armour does provide a reasonable amount of 'mechanical protection' (it's not that easy to get a spade through it, or a fork into it), but an 'earthed metal sheath can be (and sometimes is) just a very thin metal foil which undoubtedly provides far less 'mechanical protection' than does the PVC/whatever sheath that usually/often surrounds it!

Kind Regards, John

 

[JohnW2]

What about - "A cable buried in the ground shall incorporate an earthed armour or metal sheath, or both, suitable for use as a protective conductor except where installed in a conduit or duct which provides equivalent protection against mechanical damage."

Or - ... "Except where installed in a conduit or duct which provides equivalent protection against mechanical damage, suitable for use as a protective conductor, a cable buried in the ground shall incorporate an earthed armour or metal sheath or both."

I don't think that either of those change much. In both cases, "equivalent" ('protection against mechanical damage') to (the mechanical protection provided by) what?

Kind Regards, John

 

[flameport]

His reply was to the effect that he didn't want to get involved in that,

That's their choice. However installing a 10mm² cable now would allow for one to be installed at a later date. With only 4mm² another new cable would be required if/when such a thing was wanted.

Unless this cable is excessively long, the cost difference between 4mm² and 10mm² is insignificant.

 

[Roy22]

That's their choice. However installing a 10mm² cable now would allow for one to be installed at a later date. With only 4mm² another new cable would be required if/when such a thing was wanted.

Unless this cable is excessively long, the cost difference between 4mm² and 10mm² is insignificant.

What's the general feeling about the splitter unit he wants to put in meter box? Partly he was keeping away from an old Consumer Unit, and the outside run avoids floorboards etc. Is this an OK thing or a bit of a bodge?

 

[flameport]

Depends what they mean by 'splitter unit'.
Cables require overcurrent protection, so just joining the cable to what's in the meter box is unacceptable.
Shoving a mini consumer unit in there is better, but as already stated, meter cabinets are not intended for such things and consumer units designed to be used indoors are not appropriate to be installed in environments like that either.

The proper solution is to take the new circuit from the existing consumer unit, or if that's not possible due to it being full/obsolete, add a second consumer unit next to that, or ideally replace the existing consumer unit with a new one.

 

[Roy22]

Depends what they mean by 'splitter unit'.
Cables require overcurrent protection, so just joining the cable to what's in the meter box is unacceptable.
Shoving a mini consumer unit in there is better, but as already stated, meter cabinets are not intended for such things and consumer units designed to be used indoors are not appropriate to be installed in environments like that either.

The proper solution is to take the new circuit from the existing consumer unit, or if that's not possible due to it being full/obsolete, add a second consumer unit next to that, or ideally replace the existing consumer unit with a new one.

I think I'm inclined to agree with what you and others are saying. In trying to keep the cost down, by keeping away from the older Consumer Unit, he's crossed into some questionable territory, using the Meter Box to house a consumer unit as you say and then the external armoured cable run. I would sort of expect a garage to be fused from the internal Consumer Unit just like a cooker etc. Maybe too much of a 'fix' to get him the job for a lower price when he really should be suggesting a new CU and an internal cable run to it that's heavy enough to carry a future charging point.

 

[flameport]

How 'old' is the existing consumer unit? Can youo add a photo of it?

Unless the existing CU is far away from the meter cabinet, it should still be possible to have most of the cable run outside - it's only an extra hole through a wall.

 

[Roy22]

It's a probably 1995 fitted Memera 2000 with 2 empty fuse slots. One RCD protects three areas with the lights & immersion heater excluded from that. Is that too old?

 

[flameport]

Parts for that may be available, but realistically it's due for replacement.

Adding a smaller consumer unit next to the existing one is still an option.