Earthing concern

[Engineer54]

Undersized, not marked, not connected to earth, I've now put it back to management and recorded it in to the site log book.
C&I is a term we use for Controls & Instrumentation, might just be a term our company uses. That earth bar on the left is for a clean earth but strange that the controls guys alway say we don't have a clean earth, seems we have, I'm sure someone has connected those copper tapes to the wrong bar.

You can't say that it's not connected to earth unless you have tested, and proved that statement. The chances are it is connected to earth, the problem you mainly have, is not knowing how and where it's connected to earth!!

 

[Engineer54]

Undersized, not marked, not connected to earth, I've now put it back to management and recorded it in to the site log book.
C&I is a term we use for Controls & Instrumentation, might just be a term our company uses. That earth bar on the left is for a clean earth but strange that the controls guys alway say we don't have a clean earth, seems we have, I'm sure someone has connected those copper tapes to the wrong bar.

What i don't understand, is why the controls and instrumentation earthing bar, is bigger than the main electrical installations MET bar?? lol!!

 

[tissparks]

You can't say that it's not connected to earth unless you have tested, and proved that statement. The chances are it is connected to earth, the problem you mainly have, is not knowing how and where it's connected to earth!!

Yes, you're quite right, having a drama moment, chances are it is, just not where and how i expected.

 

[tissparks]

What i don't understand, is why the controls and instrumentation earthing bar, is bigger than the main electrical installations MET bar?? lol!!

Usually if it dont like right, it ain't right!!! Then do a little investigative work before placing it on to the boss's desk :yes:And that's where it is now.

 

[Knobhead]

Usually the N-E link in main LV Switchboards is via a copper bus bar. Don't think i've ever seen the link being made by a cable. Unless earthing and bonding conductors are labeled at these larger sized MET's and Switchboards, it can be one hell of a job tracing them out once they disappear into ducts, or as sometimes the case, ....concrete!! We use split removable linked earth bars, which are also labeled as to what each section has been designated....

All the boards I installed or modified had a couple of copper tapes even though the spec was for cable.
OK 50X3 copper tape was stores stock where as the cable wasn’t (don’t ask me), it made life easier for me. The works engineer was happy because it reduced the capital cost. Accountancy in large companies is crazy!

I scrapped a fair number of older boards so had a ready supply of bus-bars to make my own MET’s up. The old Reyrolle boards had the best bars in them, laminated and riveted. Don’t think I’d have got away with mounting them vertically though, some were near 20’ long.

The older boards were all done with cable. Nothing to do with me, all I ever did with them was scrap them!
(Wish I'd taken photographs, some were a work of art)

 

[tissparks]

An update, the two earth bars in the picture have been connected incorrectly. The company that installed it are coming back to set up lightning protection so will advise us at the time. Although it was a different company that ran the cables to the earth bars so I will wait and see. Further update to come.

 

[Knobhead]

Further update to come.

Keep us updated on this.
(Good on you for questioning it in the first place. I just hope you didn't get in trouble for lifting the lid on the can of worms).

Please, make sure the system is dead before they start swaping the N>E link cable around. Or use jumpers while it's done.

I've had to deal with the aftermath of a disconected link, it's not nice!

 

[tissparks]

Thanks Tony, i think it will happen during an outage. I will add it to the method statement in case i'm not there. To be fair all the management have supported me on this apart from one. Its come back to bite him hard i think which is why he tried to warn me off. Funny thing is the lightning protection company wont talk to him for some strange reason.

 

[Engineer54]

Well if this company is going to be conducting remedial works to this installation in the near future, it might be prudent to ascertain exactly what they're intentions are going to be. You don't want to find another incorrect lash-up after they have been and gone!! lol!!