Old MEM board with no main earthing

[paulthemagpie]

Hi Guys,

I came across an old MEM board a couple days back with 3871 breakers and 5419 main switch. It was metal board with no earthing and relying on the trunking as mains of earthing (no main bonding). As well as this no RCD protecting to sockets.

Obs a fail. Would you code 1 or 2 this?

Also when recommending best course of action for remedials. Would you either a. Recommend a full board upgrade, or b. recommend main earthing added and a second small board to divert cables for sockets through a RCBO?

Ka value of the 3871's are 9ka so okay for continued use

thanks

 

[Andy78]

Just as the last thread, You are the inspector and producer of this technical report so you should be aware of the definitions of the C codes and when to apply them.

I would have issued a danger notice and recommended temporary protective measures in the form of RCD protection and an earth rod at the very least.

 

[Risteard]

I'm a bit confused.

Firstly you state that the dist. board is unearthed. Secondly you state that it is earthed via steel trunking.

Which is the correct version?

 

[Andy78]

I'm a bit confused.

Firstly you state that the dist. board is unearthed. Secondly you state that it is earthed via steel trunking.

Which is the correct version?

I missed that bit. I assumed a domestic situation.

 

[Octopus]

What was the Ze? and what were the Zs readings?

 

[davesparks]

Hi Guys,

I came across an old MEM board a couple days back with 3871 breakers and 5419 main switch. It was metal board with no earthing and relying on the trunking as mains of earthing (no main bonding). As well as this no RCD protecting to sockets.

Obs a fail. Would you code 1 or 2 this?

Also when recommending best course of action for remedials. Would you either a. Recommend a full board upgrade, or b. recommend main earthing added and a second small board to divert cables for sockets through a RCBO?

Ka value of the 3871's are 9ka so okay for continued use

thanks

Steel trunking is permitted as an earthing conductor so that alone is compliant (you just have to prove by calculation with the adiabatic equation)

No main bonding is only potentially dangerous, not immediately.

No rcd protection is usually a C3 unless other factors are in play.

There is no such thing as a fail on an eicr, it is only an overall assessment of satisfactory or unsatisfactory.

 

[paulthemagpie]

I'm a bit confused.

Firstly you state that the dist. board is unearthed. Secondly you state that it is earthed via steel trunking.

Which is the correct version?

I meant unearthed in the form of a earthing cable but relying on trunking only as a means of earthing

 

[telectrix]

still vague. is the trunking used as a main earth, or as a cpc for circuits?

 

[davesparks]

I meant unearthed in the form of a earthing cable but relying on trunking only as a means of earthing

Which is completely fine and you can install it exactly the same today in compliance with the regulations, subject to confirming the size via the adiabatic equation.
It's no different to installing your outgoing circuits in trunking and conduit, you use the steel enclosures as your cpc.

 

[7029 dave]

^^^^^ as above.