230v CONSTRUCTION site supply

[SgtTrojan]

Whilst teaching Electrical Safety in Dubai last year I took the group around a local construction site. Here are a few snaps.

Untitled

• SgtTrojan
• 7 Jan 2011
• 1

An exposed consumer unit on a site.
Flexes from here went to supply twin 230v sockets on wooden boards and were dragged around the site by their users.
What do you notice about the supply?

Untitled

• SgtTrojan
• 7 Jan 2011
• 1

Within a switch room. Basic protection granted?

Untitled

• SgtTrojan
• 7 Jan 2011
• 1

Safe isolation?

 

[bernardgreen]

Construction site

First thing is the incomer appears to be supported by the earth conductor with a lot slack on the live and neutral conductors.

One jerk on the incoming could take out the earth connection and leave live and neutral connected.

 

[SgtTrojan]

Double postings

 

[SgtTrojan]

Well, look at the colours. Look again at the supply cable.
BTW The cover was not removed to take this picture.

 

[bernardgreen]

The colours do seem a bit strange, but then in the USA black is live and white is neutral. And Germany used to use red for earth.

I can only see three wires in the neutral block yet there appears to be three supplies from the board.

 

[SgtTrojan]

It is a 5c supply cable (on the left). The black loops out of the pic and back into the terminal on the rail. The three (taped) flexes are radials to the twin socket I mentioned above.

So what's wrong?

 

[matt1e]

no earthing

 

[SgtTrojan]

Yes. The earth is twisted around the supply cable.
Anything else?

 

[bernardgreen]

Yes. The earth is twisted around the supply cable.
Anything else?

Not really, it looks OK for a non UK temporary power supply. It looks better than some of the permanent factory wiring I have seen outside the UK.

 

[londonboy]

MCB's not labelled?

 

[xr4x4]

bottom left and middle?

there looks like there two mains incoming? and the wires are different colours..

 

[ban-all-sheds]

MCB's not labelled?

That's probably a good thing.

Like maps, the only thing worse than no labels are wrong ones, and looking at the overall quality of that, what would be the chances of the labels being correct?

 

[MrTinker]

Yes. The earth is twisted around the supply cable.
Anything else?

Anything to do with the 3ph MCB per chance

 

[mbga9pgf]

Yes. The earth is twisted around the supply cable.
Anything else?

Anything to do with the 3ph MCB per chance

You know how it is here in the middle east. very few standards. Labour is cheap and if a bangladeshi zaps themselves to death, well, there are thousands more on the boat...

I dont agree with the above btw, but as you will know, "Inshallah" rules in this part of the world, so does saving money for polished marble facias instead of safety standards on construction sites.

We have the same issues in aviation as I hear from relatives working in the construction/civil engineering industry.

 

[SgtTrojan]

Yes. The three phase breaker used as a "loop"'for the other site supplies. The busbar is modified to allow for a single line connection.
The earth is not connected.
The neutral is brown.
It was also a normal thing to see whereby the three radials all connected into one 32A cb. I can't remember with this one though.

How would you code it on a periodic inspection?