Novices question regarding steel conduit

[str]

Quick question on the use of steel conduit to carry electrical cables - they have been used in my house, although maybe only on the lighting circuit - would this be the norm?

Does the cable need to include an earth or is this taken care of by earthing the steel conduit? Reason I ask is that some light cables in the ceiling don't appear to have an earth?!

the above is just for my own curiosity - we have having some fairly major work carried out soon, so I will have a spark take care of any issues.

Also, when I top up the insulation in the loft - can I run the insulation material over the steel conduit (I know you have the lay any exposed cables over the insulation to avoid overheating.

cheers

 

[ban-all-sheds]

Quick question on the use of steel conduit to carry electrical cables - they have been used in my house, although maybe only on the lighting circuit - would this be the norm?

It used to be fairly common, or possibly even more so. Been a while though, but the use of C&N slip conduit for drops in walls persisted.

Does the cable need to include an earth or is this taken care of by earthing the steel conduit?

It can be, and if properly done it's a good system, but it's time consuming to do properly and a PITA to modify and extend.

Reason I ask is that some light cables in the ceiling don't appear to have an earth?!

Maybe they really don't. How old is the wiring? What type of cables? Are they rubber insulated? Do they have multi-stranded tinned conductors?

the above is just for my own curiosity - we have having some fairly major work carried out soon, so I will have a spark take care of any issues.

Leave it to him then - just don't install any metal switches or lights that need an earth until it's sorted.

If he's any good he'll do a full inspection before starting any major work.

Also, when I top up the insulation in the loft - can I run the insulation material over the steel conduit (I know you have the lay any exposed cables over the insulation to avoid overheating.

You know wrong - at least as far as lighting cables go insulation can be laid over them. Shower cables are a different matter...

Tell the electrician how much insulation you plan to install and he will use the right sized cables to avoid problems.

 

[str]

thanks for that.

all the cabling in the house appears to be fairly new - certainly modern looking cable, looks the same as you can buy now. The fuse board is a modern board with trip switches so the house has been rewired at some point (we have only been there for 5 years).

I should know more (my dad was a spark) but I obviously didn't pay enough attention when he took me on homers and had me crawling under floors to pull cables!

 

[holmslaw]

..

 

[ban-all-sheds]

all the cabling in the house appears to be fairly new - certainly modern looking cable, looks the same as you can buy now. The fuse board is a modern board with trip switches so the house has been rewired at some point (we have only been there for 5 years).

some light cables in the ceiling don't appear to have an earth

 

[securespark]

Non rubber cable came in in the early 60's. The regulations requiring cpc's in lighting circuits were introduced in 1966.

So it is entirely possible you have lighting cables without cpc's.