Picture 1 – Temporary electrical submain cables
===== RELATED ARTICLES: Temporary Electrical Earthing Pictures | Electrical grounding electrode pictures | Electrical installation pictures
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I wish to make one thing very clear on temporary electrical installations.
The installations for purposes of temporary electricity supply are not "nice" installations in majority of construction scenarios.
If I am to show only the nice and proper temporary supply installations on this blog, then I only serve the readers with only less than half of my experience on this matter.
With that also it means that only less than half of the lessons can be learned by beginners of electrical installations.
With all these good and bad examples of electrical installations, beginners can learn more of the real life scenarios that they will face when they start work at real construction sites.
Now back to the pictures.
Picture 1 above shows how the low voltage (LV) submain cables are installed in this project.
These cables are 4-core, steel-wire-armored copper cables. They connect the temporary main switchboard to individual sub-switchboard inside the building under construction.
Personally I do not really have any objection to the way the contractor installed these cables because they are steel wire armored cables even though they look a little unsightly.
They however should be protected from accidental damage. Some sort of barricade should be installed because one of the main construction roads is just a few feet away from the steel fence.
An alternative might be to raise the temporary cables higher so that any possible accidents by construction vehicles would not hit the electric cables.
Notice the picture label that I put on the right of the picture: temporary earthing electrode. The indication pointed to a white signboard.
Actually this was one of a few improvements made by the main contractor to the temporary electrical installation at this project site. I have sent a post earlier on this issue, which you can read here, Temporary electrical panel and cord pictures.
The warning sign indicating the location of temporary electrical grounding is a very important safety matter. If the earthing is damaged and not functioning well enough, hundreds of workers at the job site faced risks of electrocution or serious injuries from electric shocks every day.
If you have not seen these sorts of injuries before, you can see them see them at this post, Electric shock injury pictures. If you have seen then, then don’t. Once should be enough. I lose my appetite for food almost a whole day every time I look at those pictures.
The temporary grounding electrode should have also been barricaded for protection from damage, which was also carried out one or two weeks after this photograph was taken.
Later the temporary submain cables on the fence were also provided with some DANGER warning signs.
Picture 2 – Temporary site flood lighting
This flood light was installed on the fence not far from the sub-main cables in Picture 1.
If I remember it correctly, this flood light fixture was 400 watt, IP 65 metal halide.
You can see more photographs of temporary lighting at another post, Temporary lighting installation pictures.
Picture 3 – Temporary electrical panel without earthing connection
This electrical panel was installed to operate a machinery at a very wet condition and outdoor.
The electric panel was very neat and of a high quality.
A brief look inside might not alarm you at all. It did look good.
However, a closer observation revealed something sinister. The panel did not have the electric shock protection at all.
In case some readers may wonder, the machinery supplied by this panel was not an automated machine. It was a manned at the machine itself with the motor near the operator and in a very wet area.
You can read the post here, Electrical panel pictures. There are more pictures of this electric panel there also.
Picture 4 – Burned 13A socket outlet
This is a temporary switched 13A socket out installed on a temporary electrical panel at a construction site.
Notice burn mark around one of the socket pin holes. This is the “LIVE” terminal of the socket.
You would get this mark if you use the socket the way photographed in Picture 2 (check the photo at the post link below). It could have been caused by fire sparks when the live wire was pulled out of the socket without turning off the socket switch.
It could also be caused by fire or heat because the contact between the live conductor and the socket terminal inside was not good enough to handle the current taken by the electric tools being operated.
In any case, this would be a very good source of electrical fires.
This temporary DB was actually installed outside of the new building and there was not really anything that could catch fire. However, if it were inside the building, it would be also a real fire hazard.
Visit this post, Temporary socket outlet pictures, to see more photos of temporary electrical panels and temporary socket outlets.
Picture 5 – A method(?) for a temporary electrical distribution
Would you believe it if I say that the above picture was a distribution system for a temporary electrical supply at a building under construction?
I took the above picture quite a while back. I thought it was interesting.
You can see the rest of the pictures here, Temporary electrical distribution.
Picture 6 - Another temporary electrical panel
I saw the above temporary installation at a new project I just get involved in. So I took some pictures and sent out the following Site Memo:
SITE MEMO:
Dear Sir,
Re: Temporary electricity supply: Electric shock hazards
As I have explained on Saturday last week, please find attached photographs of the temporary electrical cabling.
I believe the photos are self-explanatory. However, I wish to highlight the following points:
1. Many extension cords do not have the grounding cable.
2. The extension cords are laid on the floor along main work traffic. Cables can be damaged leading to exposures of LIVE cables. A few have already been damaged and improperly patched up.
3. Observe that the area is a very wet area. The risks of electrocution here is very high.
I suggest the following action be taken IMMEDIATELY:
1. If possible, the temporary DB is relocated to a more suitable and DRY area.
2. Enforce the rules that all subcontractors run their extension cords at high level along walls or columns.
3. Enforce the rules that all extension cords have a working grounding conductor.
It is my opinion that the present situation is VERY DANGEROUS and a fatal electric shock accident can happen any time.
Regards,
Lee Wan Seng
Resident Electrical Engineer
Visit this post, Temporary electrical cabling, to see the rest of the pictures.
That’s all I have time for today. I will update this post with more pictures soon.
Chiao.
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