MEA cleaning insulators using high-pressure water jets

[webfact]

MEA cleaning insulators using high-pressure water jets

By THE NATION

 

 

The Metropolitan Electricity Authority (MEA) has been cleaning insulators on power lines in Bangkok, Nonthaburi and Samut Prakarn to prevent electrical shocks.

 

Phasuk Sampunnachote, MEA public relations director, said that insulators on power lines help insulate high voltage electricity as well as protect the lines against severe weather. “However, insulators can get dirty from dust and as a result accumulate heat that could cause electrical shock or damage to power lines,” she said.

 

 

“To ensure public safety, MEA has been cleaning insulators in metropolitan areas with high-pressure water jets, which is a modern technology that allows staff to work on hot line, also know as cleaning without cutting the power, to ensure seamless services to MEA customers,” said Phasuk. “The old method involved removing the insulators and taking them down to clean, which will require cutting power supply and usually takes more time.”

 

 

“MEA has a schedule to clean insulators in its responsible areas every 1-2 years, depending on the dust level that could accumulate on the insulators,” she added.

 

“If you witness damaged powerlines and other equipment, please contact all branch offices of MEA or MEA Call Centre 1130, Twitter: @MEA_news, Line: @meathailand, Facebook: @Metropolitan.Electricity.Authority or download the “MEA Smart Life” mobile app, available for both Android and iOS users.

 

Source: https://www.nationthailand.com/news/30391855

 

-- © Copyright The Nation Thailand 2020-07-24

 

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[Grumpy one]

I'm sorry but as a kid I learnt that water and electricity don't mix.

If you think differently, go pee on an electric fence   

[lopburi3]

1 minute ago, Grumpy one said:

I'm sorry but as a kid I learnt that water and electricity don't mix.

If you think differently, go pee on an electric fence   

Electric does not flow in water - you were pissing too many minerals.  ????

[Crossy]

8 minutes ago, lopburi3 said:

Electric does not flow in water - you were pissing too many minerals.  ????

 

Yup, I've done the electric fence act too, on the way home from the boozer of course (so lots of dissolved minerals).

 

The chaps doing the cleaning are in insulating buckets and the stream is too long to lead to any shock hazard anyway.

 

That said, you won't catch me hosing down any power supplies.

[Peterw42]

11 minutes ago, Grumpy one said:

I'm sorry but as a kid I learnt that water and electricity don't mix.

If you think differently, go pee on an electric fence   

Pure water doesn't conduct electricity, thats why you put distilled water in a battery.

[xylophone]

6 minutes ago, Peterw42 said:

Pure water doesn't conduct electricity, thats why you put distilled water in a battery.

True enough, pure water does not conduct electricity, and it's only the impurities in normal water which helps with the conductivity, so as others have mentioned, still good to stick to the old adage, "electricity and water don't mix"...... this especially in Thailand where the wiring/appliances/earths can be extremely suspect!!!

[Rookiescot]

9 minutes ago, Peterw42 said:

Pure water doesn't conduct electricity, thats why you put distilled water in a battery.

You think that water will be pure?

[Peterw42]

1 minute ago, Rookiescot said:

You think that water will be pure?

Pure enough not to be a great conductor, either way even salt water wont conduct unless it has a path to earth or a lower potential.

You can literally touch those wires so long as you are not earthed or touching another wire

[kotsak]

23 minutes ago, Rookiescot said:

You think that water will be pure?

Purest you can find from the nearest khlong ????

[Dazinoz]

3 hours ago, Peterw42 said:

You can literally touch those wires so long as you are not earthed or touching another wire

Depends on the voltage in that wire. I used to work in a power station in Australia. The transmissions lines from it to Sydney are at 330,000 volts. At that voltage if you touch the wire even high in the air there is still enough current flow through you to the air to kill you and thats why workmen actually touching the line wear a mesh suit called a Faraday suit that conduct the electricity around the body. Cant remember at what voltage a Faraday suit is required.

 

I used to do switching on the 330,000 lines in the switchyard. When earthing these lines we had to be "proven dead" before earthing. This involved a specialised testing instrument attached to a very long wooden pole. You first had to touch the instrument to the dead circuit, then to a live one to prove instrument working then back to dead line and hang it there until earthed. I felt comfortable doing this unless it rained and water running down pole.

Edited July 24, 2020 by Dazinoz

[DrTuner]

Quote

high-pressure water jets, which is a modern technology

Yeah. a bit more recent than The Wheel. Must be pretty novel to the natives.

[DrTuner]

6 hours ago, lopburi3 said:

Electric does not flow in water - you were pissing too many minerals.  ????

It does but not very efficiently. Resistivity is around  2 to 200 Ω·m for drinking water.

https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity

 

Humans conduct a lot better, especially when surface is wet so there's better contact. In other words, when pissing on an electric fence, don't touch it with the danglies.

 

 

 

[xylophone]

2 hours ago, Dazinoz said:

Depends on the voltage in that wire. I used to work in a power station in Australia. The transmissions lines from it to Sydney are at 330,000 volts. At that voltage if you touch the wire even high in the air there is still enough current flow through you to the air to kill you and thats why workmen actually touching the line wear a mesh suit called a Faraday suit that conduct the electricity around the body. Cant remember at what voltage a Faraday suit is required.

 

I used to do switching on the 330,000 lines in the switchyard. When earthing these lines we had to be "proven dead" before earthing. This involved a specialised testing instrument attached to a very long wooden pole. You first had to touch the instrument to the dead circuit, then to a live one to prove instrument working then back to dead line and hang it there until earthed. I felt comfortable doing this unless it rained and water running down pole.

Your post brought back some memories of when I was working in the Sahara desert, contracted to BP as an electrical engineer, and one of the jobs I was expected to do, mainly because the Libyans couldn't be trusted to do it, was to clean the overhead line insulators, and although it's been a long time now I do believe the voltage was anywhere between 11 KV and 32 KV.

 

The object of the exercise was to go up in the cherry-picker, inside of the fibreglass bucket and using a long fibreglass pole with something akin to a feather mop attached to it, to clean the insulators and the insulator arms.

 

First time, the hydraulic pump on the old American truck they had, decided to blow up and another one was ordered from somewhere, and as per usual in the Sahara, you really had to use what you could get hold of, and this didn't dawn on me until after this incident.............

 

We drove the truck out to the beginning of the overhead lines and I got in the bucket along with all the gear and a pair of gloves and proceeded to push the lever to ascend. Well I ascended at a fantastic rate of knots and damn near collided with the overhead lines before there was a huge explosion and we were all covered in hot hydraulic oil and luckily enough the bucket and the leverage mechanism put me safely back down.

 

Turns out the Libyan mechanics had used any old pump they could get hold of and it was far too strong (pressure -wise) for this unit, and it blew one of the hydraulic lines.

 

Tried again when they had fixed it and stuffed around, and was assured that the new pump motor was okay.

 

Anyway up I went again and once I got the pole out in front of me, level with the insulators and started to clean, them I could see the electricity "dancing" along the pole and towards me and although I could only just feel a tingle, all the hairs on my arm were standing up, as were the hairs on my head, much to the amusement of the Libyans nearby.

 

As I recall, I managed to clean a few insulators before the whole truck (which was probably about 25 years old and very dilapidated) and the mechanicals/hydraulics therein, decided to give up the ghost, so fortunately I didn't get to finish the job.

 

Three months later I was out of there and onto another contract in Nigeria. Memories.
 

[Russell17au]

Back in 1980's in the New South Wales Bush Fire Brigade in Australia we were trained to fight electrical fires in power poles and other power installations with high pressure water because with low pressure you have a continual stream of water that the electricity can travel along but with high pressure you do not have that continual stream, you actually have droplets of water because with high pressure the water is more of a spray than a continual stream of water.

[kokopelli]

7 hours ago, Peterw42 said:

Pure water doesn't conduct electricity, thats why you put distilled water in a battery.

Distilled water is used in batteries so as to not introduce contaminants.  The water is added to the acid which is in the battery and the acid is a good conductor. 

[PFMills]

Insulator washing is not new. Very common in UK Substations more than 40 years ago and that was on 275kV/400kV lines. But we always tested the purity of the water in the Insulator Wash Tank first!

 

On one occasion there was a leak in the underground wash pipework and dirty water entered ... flashover .. tripped the associated 660MW generator.

Edited July 24, 2020 by PFMills

[Scott Tracy]

Never add water to acid, always the other way round.

 

High pressure water (droplets) and insulators are fine, otherwise people would die on the ground when it rains.

[Wullie Mercer]

It was called "Live Line Washing" when I first seen it in Oman in the 80's, carried out by a Spanish firm. As an Electrical Engineer I was sceptical, but if done PROPERLY it is very good and efficient.

[crutchy26]

They used a similar technique in Au. But they pulse the water to ensure no path & likely for impact against the dust/silt.

 

[Grumpy one]

23 hours ago, Peterw42 said:

Pure water doesn't conduct electricity, thats why you put distilled water in a battery.

So you think these guys are using pure water from the Bangkok water mains  

[Grumpy one]

23 hours ago, Peterw42 said:

Pure water doesn't conduct electricity, thats why you put distilled water in a battery.

Bangkok water mains deliver PURE water do they  

[Peterw42]

3 minutes ago, Grumpy one said:

Bangkok water mains deliver PURE water do they  

Probably not pure in terms of bacteria etc but probably somewhat pure in terms of dissolved salt/minerals that allow it to conduct electricity.

[Pib]

We have a high voltage, long distance power lines and towers that run through the middle of my Bangkok moobaan....you know the kind of really tall towers (like around a 100 meters tall) like below for example. 

 

Last year during certain times of the year in certain type of weather you could hear "crackling, sparking" sounds which was due to dirty insulators.   The electric company came out and spray-cleaned those insulators.  Since the towers were so tall the spray could barely reach them but it fixed the problem....no more crackling, sparking sounds. 

 

 

 

[lopburi3]

22 minutes ago, Peterw42 said:

Probably not pure in terms of bacteria etc but probably somewhat pure in terms of dissolved salt/minerals that allow it to conduct electricity.

Actually it is river water and runs about 150 on TDS meter (your RO water probably less than 20).