Pyro..

[303mc]

Hey all.
I live on the top floor of a 3-storey block of flats that were built in 1964. My main supply is TN-S, and the supply from the meter room downstairs is 2 core pyro...
The CU was changed just after i moved in last year. I have a test certificate at work with the readings on. Lighting needed to be replaced because there was no earth, and i was advised the original under floor heating shouldnt be used.
I had a new bathroom put in last week, and the guy said i'd need to bond my bath and pipes before he came back to tile the walls.
I was wondering where i should bond to. I have searched the net and looked in my copy of the OSG, but from what i can see i need to bond to the main earthing terminal (downstairs) not the earth bar in the CU...
Can anyone advise me on this please.
I was also wondering about this nasty looking pyro.. is it up to spec to still use it as the main earthing conductor?..
My REC fuse is 60a and the conductors in the pyro look like 16mm. i have a 40 amp cooker, 40 amp shower, 22amp instant water heater, 2 ring mains, an immersion heater and the lights in the hall are on their own breaker for some reason... does this all sound ok on this old cable?
I know it would be a b****** to replace the pyro as it runs through other flats and i think may be set in concrete, but if its got to be done then its got to be done.
i am only the second out of about 50 to have had their electrics looked at, quite worrying really if you saw the state mine was in. For starters the brass light in my bedroom was live because someone had put a screw through the cable, and there was no fuse wire in my board.. many copper strands probably from some flex
There is an AGM soon so i can put my points across.
Any advice at all would be greatly appreciated as i can't seem to find much about pyro being used as the main incomer..
Thankyou!

 

[andy]

the load should be OK on 16mm. after all, the fuse is at 60A. pyro is very good providing dampness doesnt get into it, but if the ends are done properly this shouldnt be an issue. you could run the earths to the earth terminal in the CU. most newer CU's have 2 extra earth terminals for the water and gas

 

[ChrisRogers]

just have the insulation resistance of the pyro checked, pyro lasts forever if installed properly.

 

[ban-all-sheds]

I was wondering where i should bond to. I have searched the net and looked in my copy of the OSG, but from what i can see i need to bond to the main earthing terminal (downstairs) not the earth bar in the CU...

Regulation 601-04-01 requires that the protective conductor terminals of each circuit supplying Class I and Class II electrical equipment in zones 1, 2 or 3, and extraneous-conductive-parts in these zones, are all connected together by local supplementary equipotential bonding conductors complying with Regulation Group 547-03.

There is no requirement to connect the supplementary equipotential bonding back to the MET.

 

[baldelectrician]

it is quite common (up here) to have pyro running to tenement flats (they don't do it now - probably cost)

The copper outer of the pyro gives an excellent earth, although it is the rec's property and they should provide an earth from it.