Monday, October 12, 2009

Electrical panel pictures: The earth was missing

The following pictures of a temporary electrical panel show another common type electrical hazard at construction sites. I took these photos at a building construction site about four months ago.

This panel was located under a shade at the concrete mixing station of the construction site. As you can see, the location of the electrical panel was full of water. No, it was not due to rainwater. The location was always that way, because the plant consumed a lot of water daily. The situation presented a very high risk of electrocution not just to the worker operating the concrete mixing plant, but also to other workers.

Someone at the site told me that the electrical panel was too high above the water. So there was not really much risk. What do you think?

Picture 1 - Electrical panel location (Click on the picture to see full size)

Electrical Panel Image 1
I opened the electrical panel door to check inside (See Picture 2). The panel was a good quality and relatively new. The internal wiring inside the panel was also done nicely and it was neat.

But wait.... Where is the earthing to the panel? There was good earth wiring inside the panel - the green wires. All neatly run and properly terminated to the copper earth bar. But the connection just stopped there. There was no outgoing connection to earth (See Picture 3).

Picture 2- Electrical panel inside view (Click on the picture to see full size)

Electrical Panel Image 2
Picture 3- Earthing copper bar without connection to earth (Click on the picture to see full size)
Electrical panel Image 3
I checked the incoming twisted cable. It was a four-core. No earth cable anywhere (See Picture 4). I checked around the panel to see if the person who installed it used a different conductor and run it direct to earth somehow. Nope, no other conductor installed.

The conclusion? The electrical panel was not earthed at all. So what happens when there is a considerable leakage current? What protects the worker at the concrete mixer machine there, especially with the wet condition there? Sadly to say... no protection at all.

Feeling exasperated, I checked inside the electrical panel again. Surprise... there was not even an earth leakage circuit breaker there, or any other type of residual current protective device.

Picture 4- Incoming 4-core twisted cable without earth (Click on the picture to see full size)

Electrical Panel Image 4
I have to go now. I will add more info to this post in the near future. I know there are questions in the minds of some of the readers relating to the electrical installation shown in these pictures. The electric shock protection issue can be tricky sometimes.

Until next time...
Note: There are more pictures at this post: Temporary electrical installation pictures.

Copyright Electrical Installation Wiring Pictures - Electrical panel pictures - The earth was missing

1 comment:

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