TT-no earth rod

[Engineer54]

Loads of tt's round me. all in the regs... Not many earth pits.. not entirely essential.. Into most ground 1 mtr rod is fine (depending on install...) I got a rod stuck 200mm in one day. Thought I would test it.. Same reading as the 1 mtr rod i put in next to it...

Cant believe the no earth install.. And in this sort of case agree with the Electrical Trainee generation.. :smilewinkgrin:

This post just shows that you know absolutely Nothing about installing a TT earthing system!!!

 

[snoopydo]

what is the proceedure when coming across dangerous installs like this? would you riddor it like a gas installation?

 

[Steve Richards]

Should also remember not to install a rod within rod x 2 length of other extraneous parts buried in the ground e.g metallic water or gas mains.

 

[Engineer54]

Should also remember not to install a rod within rod x 2 length of other extraneous parts buried in the ground e.g metallic water or gas mains.

Fine if you have a service layout drawing to hand!! Neigh on impossible to confirm one way or the other in normal circumstances though!!

The best way is as Marvo employs, dig a square hole to around a metre deep, then drive your rod(s) in the ground. Then you can be relatively sure, that at least your not going to hit a service pipe... lol!!!

 

[rich.250]

25 ohms is a good enough Ra although i would still supply a 100mA rcd upfront (type s) and then follow the need for 30mA for additional protection where required.

 

[rich.250]

Are 100ma RCds still required? they have got a 16th ed split load board. half circuits on 30ma rcd, other half just MCBs.

also, for TT is the max Ze 200 ohms.

Table 41.5 sets out the maximum for different ratings of RCDs

 

[Marvo]

at least your not going to hit a service pipe... lol!!!

It's the thought of hitting an MV cable that scares the hell out of me. I saw a bulldozer do it one time and it became something of a phobia after I saw the ensuing mayhem.

I got a rod stuck 200mm in one day. Thought I would test it.. :smilewinkgrin:

Are you being serious or did you mean 200cm? It would be a bit of a pointless exercise doing any testing on a rod that's only 20cm into the ground.

 

[trev]

It's the thought of hitting an MV cable that scares the hell out of me. I saw a bulldozer do it one time and it became something of a phobia after I saw the ensuing mayhem.

My mate's Dad was a HIAB op, I'll leave you to guess the rest but it wasn't pretty