What you see below are two units of weatherproof 13A switched socket outlets.
Picture 1 – Weatherproof 13A switched socket outlets
==== RELATED ARTICLES: Electrical socket extension unit | Feeder pillar single line diagram | 1- Phase ELCB connection pictures | Metal-clad socket outlets | Electrical installation pictures
====
Weatherproof 13A outlets are very useful accessories to buildings and homes. With them large amount of spaces can be turned into good use.
The picture above shows one example of an existing installation that has turn corridor areas into very comfortable study areas where the students and the university staff can use laptop for many long hours in fresh outdoor air.
Nowadays a study table (some people call it reading tables) would definitely need 13A power outlets. Even when someone is not using the internet, often a laptop is felt to be necessary for reading due to vast amount of easily downloadable reading materials from the internet.
Most of the downloaded materials are usually not printed out to paper, but carried around in laptops for the time when a small opportunity for reading them becomes available.
Below is a zoomed out view of one of the study tables at one of the corridors at the ground floor level.
Picture 2 – Weatherproof outlet installation environment
If you look at the height of the ceiling slab, it is almost two volume in height. This is a tropical country with great many days of rains.
An electrical socket around the location of the table and chairs would definitely be exposed to sun and rain. More importantly, an unsuitable electrical outlet would definitely result in a high risk of electric shock hazards.
That is why a suitable electrical outlet fixture is necessary.
Picture 3 below shows a closer view of the outlet opening and cover. Here you can see the rubber gasket better. The gasket prevents ingress of water into the socket even when the laptop plug is in place.
Picture 3 – Closer view of the rubber gasket
Picture 4 – Rubber gasket with the socket cover at the closed position
Picture 4 above shows the view of the weatherproof socket from below when the outlet cover was in the closed position.
This was not exactly the same outlet as in the previous pictures. However it was exactly the same type and model.
The previous pictures were taken during daytime at the ground floor of the building.
During the night, however, it crossed my mind that maybe I should have taken a better shot of the rubber gasket from below the socket. I was then at another reading table at a fourth floor corridor of the same building.
I also took a shot of the conduit entry into the outlet fixture as shown in Picture 5 below.
Picture 5 – Conduit entry into the weatherproof socket
Observe that each outlet fixture is provided with two pre-made conduit openings at its topside. This is for convenience of looping the wiring to outlets at another location.
Of course, if this is not provided, a tee-off draw box can be installed at a point along the conduit.
Notice also in the previous picture (Picture 4) that another two pre-made openings are available at the bottom side of each unit.
This gives the alternative of have the conduit entry from below or the top of the outlet fixtures.
xxx MORE RELATED PICTURES xxx
I attach below a few more pictures of weather-proof outdoor socket outlets for readers who need them.
This new extension on each of my existing posts will be a live section where I will keep adding new related pictures to old post.
This way I do not need to write new post just to add one or two pictures that are already related to an old post.
Picture 06 - Weather-proof 13A switched socket outlet and the conduit work at a building rooftop
The picture is from one of my old projects.
The location is on the roof top of an attached 5-storey podium block. This level is used as a secondary plant room where air-condition cooling tower and fire fighting water tanks are located.
A fire fighting main pump room is also nearby here.
Therefore, this outdoor area is a good location as a maintenance work area that may be required once the office complex is operational.
The conduit that you see along the parapet wall runs all around the roof top. IP66-rated outdoor power sockets and bulk-head lighting fixtures are installed at uniform intervals along the conduit run.
Picture 07 - Closer view of the 13A IP66 power socket
Picture 08 - The socket with the cover open
I took this shot to show you that this type of outdoor is not weather-proof during usage, unlike those at the university faculty in the main post above.
Picture 09 - The IP66 label
Beginners, please take note. This is how you know the the socket fitting is weather-proof.
You also need to make sure that the product is original. A risk of electric shock is an issue of life-and-death.
The product need to be reliable over many years in terms of the water-proofing quality.
Picture 10 - The weather-proof bulk-head light fixture
Copyright http://electricalinstallationwiringpicture.blogspot.com Weatherproof 13A switched sockets
Electrical basics for beginners | Understanding electrical installations and wiring through pictures | The concepts behind electrical room design and substations
Tuesday, November 22, 2011
Saturday, November 12, 2011
CCTV conduits color coding
I uploaded the following few pictures of conduit color coding of a CCTV (closed circuit surveillance cameras) system as a extension to an earlier post on electrical services color coding. You can click on one of the related links below to see the earlier post.
Picture 1 – CCTV conduits color code
=================
RELATED ARTICLES: Electrical Services Color Codes
=================
If you do not like labels, please forgive me. Obviously I have labeled most of things that are visible in the above picture.
Without these labels I think many readers who are just beginning to learn the electrical services inside building might get confused or unsure what is what.
In fact, without the labels, the picture may even be interpreted sideways.
As you can see from the labels, the white PVC box is the CCTV modulator box. The video signal from a CCTV camera needs to be converted into a different frequency so it can be transmitted via the signal cable to the monitoring TV.
For readers new to CCTV systems, that is why the system is called CCTV. It stands for Closed Circuit TV.
In the old days, there was the normal TV. Anyone at home can tune in to the transmitted frequency of a TV channel and see the video pictures that were being transmitted inside the broadcast frequency.
The video pictures from a surveillance or security camera can also be viewed on the same TV.
However, this video could only be viewed by television sets that were directly connected to the security video cabling system.
So it was called CLOSED CIRCUIT television. It was a surveillance video viewed on a television set. Most systems did not even have the sound back then. So it was like a silent video.
The normal TV could then be called OPEN CIRCUIT television. That was what I thought back then.
Nowadays the technology has changed so much.
In fact the surveillance do not even need the cabling. You can just visit an ordinary electronics store and buy a few surveillance cameras that do not even need the cables. The surveillance video signals are broadcast to the air. Then one can just tune in to the broadcast frequency to see the video.
I know what some of you are thinking. That way neighbors next door can also view the surveillance video, right?
Right.
So it should not be called CLOSED CIRCUIT TV anymore. However, a name is a name. There no right or wrong about it. This surveillance video system is still called CCTV even now.
Now, back to the picture. The CCTV system here is still being installed. The modulator box is still empty. There is nothing in it.
Notice the round hole opening at the bottom of the box. That is for the cabling to the surveillance unit which was not yet installed.
A surveillance camera unit can be quite expensive. It can also be easily dismantled from the mounting and removed. That means the security of the item cannot be easily controlled during construction.
That is why this is one of the items that are usually installed at the very last stage of the construction period, just before handover of the building to the owner by the building main contractor.
Now, the CCTV conduit works. Notice there are two sets of conduit work to the modulator box.
One is painted orange and the other just bare conduits without paint. The orange conduits are the conduits of 240 volt wiring to the CCTV modulator.
The one without paint is meant to contain the signal cable from the modulator to the monitoring TV. In large buildings like one where these were taken from, the monitoring TV for the surveillance cameras are usually located at the security control room.
Many buildings not only have one TV for this purpose at the control room, but maybe one TV for four cameras. That way all the locations monitored by the cameras could viewed by the security personnel simultaneously.
Picture 2 – Color code of the CCTV conduit work
This is a closer view of the color code for the CCTV system. If you look at the list of the electrical services color codes in the earlier post, the required colors were ORANGE/YELLOW/ORANGE.
Well, the outside bands of the color coding are actually orange even though you may feel they are more like red. Either my cheap camera is playing tricks on me or I need to open the camera operation manual to correct the setting.
The following picture may show the colors a bit better because the sprinkler pipes are always painted RED. Well, maybe not always but most of the time. Sometimes, the fire department allow the piping for fire services to be using colors of the surrounding area to satisfy the architectural or aesthetic needs. In those circumstances, the pipes are usually required to have red color bands.
Picture 3 – CCTV versus fire sprinkler color codes
The extra picture below is just more information on the modulator box.
Picture 4 – CCTV Video cabling and 240-volt 3-pin switched socket outlet
Here I just wanted to show you the video cabling installation and the electrical socket inside the modulator box.
The video signal modulator is an electronic system. So it requires electronic levels of voltages. It usually comes with its own voltage adapter. Therefore it is also quite a common practice to use a general purpose 13-ampere 2v0-volt socket for the purpose.
There are people who object to the use of switched sockets like this for security cameras. They say someone might just easily turn off the switch to avoid being recorded and then turn it back on when they have finished their “illegal” activities.
The event may never be noticed by the security people or the building management.
It a power wiring direct to the modulator unit is used, the intruders and their accomplice may need to cut the wiring to accomplish the same. This method may eventually be noticed and an investigation be initiated.
So there is a certain additional degree of deterrence there by using direct wiring instead of the socket outlet.
Personally this is one of the places where I really do not like socket outlets.
However, when you build buildings for someone, your preference and opinions do not count sometimes. At least by those who count.
That is life.
Copyright http://electricalinstallationblog.blogspot.com/ CCTV conduits color coding
Picture 1 – CCTV conduits color code
=================
RELATED ARTICLES: Electrical Services Color Codes
=================
If you do not like labels, please forgive me. Obviously I have labeled most of things that are visible in the above picture.
Without these labels I think many readers who are just beginning to learn the electrical services inside building might get confused or unsure what is what.
In fact, without the labels, the picture may even be interpreted sideways.
As you can see from the labels, the white PVC box is the CCTV modulator box. The video signal from a CCTV camera needs to be converted into a different frequency so it can be transmitted via the signal cable to the monitoring TV.
For readers new to CCTV systems, that is why the system is called CCTV. It stands for Closed Circuit TV.
In the old days, there was the normal TV. Anyone at home can tune in to the transmitted frequency of a TV channel and see the video pictures that were being transmitted inside the broadcast frequency.
The video pictures from a surveillance or security camera can also be viewed on the same TV.
However, this video could only be viewed by television sets that were directly connected to the security video cabling system.
So it was called CLOSED CIRCUIT television. It was a surveillance video viewed on a television set. Most systems did not even have the sound back then. So it was like a silent video.
The normal TV could then be called OPEN CIRCUIT television. That was what I thought back then.
Nowadays the technology has changed so much.
In fact the surveillance do not even need the cabling. You can just visit an ordinary electronics store and buy a few surveillance cameras that do not even need the cables. The surveillance video signals are broadcast to the air. Then one can just tune in to the broadcast frequency to see the video.
I know what some of you are thinking. That way neighbors next door can also view the surveillance video, right?
Right.
So it should not be called CLOSED CIRCUIT TV anymore. However, a name is a name. There no right or wrong about it. This surveillance video system is still called CCTV even now.
Now, back to the picture. The CCTV system here is still being installed. The modulator box is still empty. There is nothing in it.
Notice the round hole opening at the bottom of the box. That is for the cabling to the surveillance unit which was not yet installed.
A surveillance camera unit can be quite expensive. It can also be easily dismantled from the mounting and removed. That means the security of the item cannot be easily controlled during construction.
That is why this is one of the items that are usually installed at the very last stage of the construction period, just before handover of the building to the owner by the building main contractor.
Now, the CCTV conduit works. Notice there are two sets of conduit work to the modulator box.
One is painted orange and the other just bare conduits without paint. The orange conduits are the conduits of 240 volt wiring to the CCTV modulator.
The one without paint is meant to contain the signal cable from the modulator to the monitoring TV. In large buildings like one where these were taken from, the monitoring TV for the surveillance cameras are usually located at the security control room.
Many buildings not only have one TV for this purpose at the control room, but maybe one TV for four cameras. That way all the locations monitored by the cameras could viewed by the security personnel simultaneously.
Picture 2 – Color code of the CCTV conduit work
This is a closer view of the color code for the CCTV system. If you look at the list of the electrical services color codes in the earlier post, the required colors were ORANGE/YELLOW/ORANGE.
Well, the outside bands of the color coding are actually orange even though you may feel they are more like red. Either my cheap camera is playing tricks on me or I need to open the camera operation manual to correct the setting.
The following picture may show the colors a bit better because the sprinkler pipes are always painted RED. Well, maybe not always but most of the time. Sometimes, the fire department allow the piping for fire services to be using colors of the surrounding area to satisfy the architectural or aesthetic needs. In those circumstances, the pipes are usually required to have red color bands.
Picture 3 – CCTV versus fire sprinkler color codes
The extra picture below is just more information on the modulator box.
Picture 4 – CCTV Video cabling and 240-volt 3-pin switched socket outlet
Here I just wanted to show you the video cabling installation and the electrical socket inside the modulator box.
The video signal modulator is an electronic system. So it requires electronic levels of voltages. It usually comes with its own voltage adapter. Therefore it is also quite a common practice to use a general purpose 13-ampere 2v0-volt socket for the purpose.
There are people who object to the use of switched sockets like this for security cameras. They say someone might just easily turn off the switch to avoid being recorded and then turn it back on when they have finished their “illegal” activities.
The event may never be noticed by the security people or the building management.
It a power wiring direct to the modulator unit is used, the intruders and their accomplice may need to cut the wiring to accomplish the same. This method may eventually be noticed and an investigation be initiated.
So there is a certain additional degree of deterrence there by using direct wiring instead of the socket outlet.
Personally this is one of the places where I really do not like socket outlets.
However, when you build buildings for someone, your preference and opinions do not count sometimes. At least by those who count.
That is life.
Copyright http://electricalinstallationblog.blogspot.com/ CCTV conduits color coding
Sunday, October 16, 2011
Substation rooms layout diagram
Below is the layout of the electrical rooms for a post that I sent earlier (See here: Cable ladder pictures).
Diagram 1 – Overall layout of the substation electrical rooms for a new office building
=================
RELATED ARTICLES:
Building’s electrical room layouts | Electrical busduct installation pictures | Electrical installation pictures
=================
The earlier post was about cable ladders. I know it can be difficult for some beginners to imagine the overall arrangement of the electrical rooms (and therefore the cable ladders) at the substation without the aid of some layout diagram.
So the above diagram should be able to help.
Keep in mind that the room layout is not a hypothetical layout. It is from the electrical substation of a building project that has been completed and commissioned.
I stripped the original layout drawing of many of the details. My intention is to help beginners slowly digest the logic and reasoning of why a substation and electrical rooms are designed the way they are.
I realize that many readers here feel that substation layouts are typical. Their designs are quite standard and therefore lengthy discussions about them are not really necessary.
That may be so if the subject of the discussion is about distribution substations. Those are substations built by the supply authorities for the purpose of electricity distribution in their supply networks.
However, when it comes consumer substations inside a building or facilities, the story can be really different.
The root of the problem is space. The size of the spaces allocated for electrical rooms and their locations can cost a lot of money. No building owner would allow a transformer room be allocated at the prime areas (i.e. the areas where dollars per square meter of rentable space is high) of their buildings.
Likewise, no design architect would support it either unless they really have to.
So if you are a new engineer that has just started your career in a design office, this is one area you really need to pay attention to. If you don’t, one day you will find yourself spending many sleepless nights because of a badly designed substation layout.
I will send a number of posts on electrical substations and electrical rooms. This one is just the beginning.
See you soon.
Copyright http://electricalinstallationwiringpicture.blogspot.com Substation rooms layout diagram
Diagram 1 – Overall layout of the substation electrical rooms for a new office building
=================
RELATED ARTICLES:
Building’s electrical room layouts | Electrical busduct installation pictures | Electrical installation pictures
=================
The earlier post was about cable ladders. I know it can be difficult for some beginners to imagine the overall arrangement of the electrical rooms (and therefore the cable ladders) at the substation without the aid of some layout diagram.
So the above diagram should be able to help.
Keep in mind that the room layout is not a hypothetical layout. It is from the electrical substation of a building project that has been completed and commissioned.
I stripped the original layout drawing of many of the details. My intention is to help beginners slowly digest the logic and reasoning of why a substation and electrical rooms are designed the way they are.
I realize that many readers here feel that substation layouts are typical. Their designs are quite standard and therefore lengthy discussions about them are not really necessary.
That may be so if the subject of the discussion is about distribution substations. Those are substations built by the supply authorities for the purpose of electricity distribution in their supply networks.
However, when it comes consumer substations inside a building or facilities, the story can be really different.
The root of the problem is space. The size of the spaces allocated for electrical rooms and their locations can cost a lot of money. No building owner would allow a transformer room be allocated at the prime areas (i.e. the areas where dollars per square meter of rentable space is high) of their buildings.
Likewise, no design architect would support it either unless they really have to.
So if you are a new engineer that has just started your career in a design office, this is one area you really need to pay attention to. If you don’t, one day you will find yourself spending many sleepless nights because of a badly designed substation layout.
I will send a number of posts on electrical substations and electrical rooms. This one is just the beginning.
See you soon.
Copyright http://electricalinstallationwiringpicture.blogspot.com Substation rooms layout diagram
Thursday, July 21, 2011
Conduit to trunking connections
I attach here a few pictures showing the connections between electrical conduits and trunking. Some few weeks ago a reader left a message on one of my blogs asking how to connect a branch conduit to a steel trunking. So these pictures should be self-explanatory enough how to make the connection.
Picture 1 – Electrical and mechanical services above the ceiling of an office building
=================
RELATED ARTICLES: Underfloor trunking below structural rebars | MATV trunking riser | Cable ladder pictures | Electrical conduits and trunking pictures | Electrical panel under water pipes | Electrical busduct installation pictures | Electric conduit installation pictures | Electric trunking installation pictures | Electric Panel Installation Pictures | FR electric cable installation pictures | Multi storey building electric closets | Underfloor trunking pictures | Site-fabricated electrical trunking | Electrical Services Color Codes | Light switch installation pictures | Building’s electrical rooms layout | Electrical installation pictures
===========
The above picture shows some of the services inside the ceiling space of and office building.
Here you can see some conduit and trunking works. For large office floor space, conduit alone is usually not enough to contain the wiring cables from the floor distribution panels to the lighting and power points.
However, it not practical and a sheer waste to use trunking up to a final circuit point, a light point for example.
A lighting point needs only three wires of 1.0 mm.sq. or 1.5 mm.sq. to make a complete wiring. This does not need a trunking. It is also difficult to connect a trunking to a lighting fixture.
Therefore, the wiring to the lighting point needs to be routed into a conduit. The best is flexible conduit.
The following two pictures show how a trunking branched into rigid and flexible conduit.
Picture 2 – Conduit branching into rigid metal conduits
The above shows two branches into rigid steel conduits. One using a circular draw box as an adapter, and the other is connected directly to the metal trunking without any drawbox.
Either one is fine, but if you have a number of circuits to be run into the branch conduit, then using the draw box might me more preferable. It would ease the work of drawing the wire.
If the tap off needs to supply only one lighting point, then you can save one draw box by connecting the trunking to the conduit directly.
Another reason for using the draw box is when the conduit do not connect to the trunking at 90 degree angle to the connected side. In that case, you definitely need the draw box.
In any case, the conduit and trunking works is a skilled tradesman’s work. Often many aspects of the actual installation tasks require some creativity and experience to do it properly at a reasonable cost.
If some tradesman have a long list of better ways to do this connection than the ones that I show in this post, then by all means follow him.
What I show here are those that are usually practiced locally here.
Picture 3 – Another two connections at the same location
One more important aspect of the connection between the electrical trunking and conduit is how exactly to fix the two pieces of electrical container.
It is not visible how it is done from the above three pictures. I also keep forgetting to open up an electrical trunking and take the picture of the connection inside the electrical trunking.
The third piece of the component that makes up the connection is only visible from inside the trunking which I presently do not have any picture.
However, there is one place where it is easier to see that third component. It is at the connection between a rigid electrical conduit and the concealed metal box of a socket out or a wall mounted light switch. The pictures below show this quite clearly.
Picture 4 – Connection between rigid electrical conduit and a concealed metal box
I have labeled the relevant components so you can see clearly what are involved in the connection between the conduit and the concealed box.
The “copper bush” is the component that I wish to show you. It is this same component that is used between conduits and trunking. When the conduit and trunking are made of metal materials, the “bush” is usually of copper material. This provides a good electrical connection between the conduit and the trunking.
On the other hand, if the conduit and trunking are of plastics or PVC materials, which are also quite commonly used in certain types of electrical installations, then the “bush” would be made of plastic or PVC.
The functions of the copper bush are three fold: one is to keep the connection firm and strong. The second is to provide a smooth finished that would not injure the insulation of wiring cables when they are drawn through the joint or connection. Lastly it serves to provide a good electrical continuity between the trunking and the conduit.
The following three more pictures give more view of the copper bush.
Picture 5 – A closer view of the copper bush in Picture 4
Picture 6 – Copper bush at another lighting switch with some wiring being installed
Here I use a picture that has some wiring already drawn in to show you how wiring cable can be damaged if the area around the connection is not smooth enough.
Copyright http://electricalinstallationwiringpicture.blogspot.com Conduit to trunking connections
Picture 1 – Electrical and mechanical services above the ceiling of an office building
=================
RELATED ARTICLES: Underfloor trunking below structural rebars | MATV trunking riser | Cable ladder pictures | Electrical conduits and trunking pictures | Electrical panel under water pipes | Electrical busduct installation pictures | Electric conduit installation pictures | Electric trunking installation pictures | Electric Panel Installation Pictures | FR electric cable installation pictures | Multi storey building electric closets | Underfloor trunking pictures | Site-fabricated electrical trunking | Electrical Services Color Codes | Light switch installation pictures | Building’s electrical rooms layout | Electrical installation pictures
===========
The above picture shows some of the services inside the ceiling space of and office building.
Here you can see some conduit and trunking works. For large office floor space, conduit alone is usually not enough to contain the wiring cables from the floor distribution panels to the lighting and power points.
However, it not practical and a sheer waste to use trunking up to a final circuit point, a light point for example.
A lighting point needs only three wires of 1.0 mm.sq. or 1.5 mm.sq. to make a complete wiring. This does not need a trunking. It is also difficult to connect a trunking to a lighting fixture.
Therefore, the wiring to the lighting point needs to be routed into a conduit. The best is flexible conduit.
The following two pictures show how a trunking branched into rigid and flexible conduit.
Picture 2 – Conduit branching into rigid metal conduits
The above shows two branches into rigid steel conduits. One using a circular draw box as an adapter, and the other is connected directly to the metal trunking without any drawbox.
Either one is fine, but if you have a number of circuits to be run into the branch conduit, then using the draw box might me more preferable. It would ease the work of drawing the wire.
If the tap off needs to supply only one lighting point, then you can save one draw box by connecting the trunking to the conduit directly.
Another reason for using the draw box is when the conduit do not connect to the trunking at 90 degree angle to the connected side. In that case, you definitely need the draw box.
In any case, the conduit and trunking works is a skilled tradesman’s work. Often many aspects of the actual installation tasks require some creativity and experience to do it properly at a reasonable cost.
If some tradesman have a long list of better ways to do this connection than the ones that I show in this post, then by all means follow him.
What I show here are those that are usually practiced locally here.
Picture 3 – Another two connections at the same location
One more important aspect of the connection between the electrical trunking and conduit is how exactly to fix the two pieces of electrical container.
It is not visible how it is done from the above three pictures. I also keep forgetting to open up an electrical trunking and take the picture of the connection inside the electrical trunking.
The third piece of the component that makes up the connection is only visible from inside the trunking which I presently do not have any picture.
However, there is one place where it is easier to see that third component. It is at the connection between a rigid electrical conduit and the concealed metal box of a socket out or a wall mounted light switch. The pictures below show this quite clearly.
Picture 4 – Connection between rigid electrical conduit and a concealed metal box
I have labeled the relevant components so you can see clearly what are involved in the connection between the conduit and the concealed box.
The “copper bush” is the component that I wish to show you. It is this same component that is used between conduits and trunking. When the conduit and trunking are made of metal materials, the “bush” is usually of copper material. This provides a good electrical connection between the conduit and the trunking.
On the other hand, if the conduit and trunking are of plastics or PVC materials, which are also quite commonly used in certain types of electrical installations, then the “bush” would be made of plastic or PVC.
The functions of the copper bush are three fold: one is to keep the connection firm and strong. The second is to provide a smooth finished that would not injure the insulation of wiring cables when they are drawn through the joint or connection. Lastly it serves to provide a good electrical continuity between the trunking and the conduit.
The following three more pictures give more view of the copper bush.
Picture 5 – A closer view of the copper bush in Picture 4
Picture 6 – Copper bush at another lighting switch with some wiring being installed
Here I use a picture that has some wiring already drawn in to show you how wiring cable can be damaged if the area around the connection is not smooth enough.
Copyright http://electricalinstallationwiringpicture.blogspot.com Conduit to trunking connections
Tuesday, July 19, 2011
Cable ladder pictures
Below are a few pictures of one of the most important components of a building’s cable support system: cable ladders.
Picture 1 – Cable ladders at Consumer’s High Voltage Switchgears
=================
RELATED ARTICLES: Underfloor trunking below structural rebars | MATV trunking riser | Substation rooms layout diagram | Conduit to trunking connections | Electrical conduits and trunking pictures | Electrical panel under water pipes | Electrical busduct installation pictures | Electric conduit installation pictures | Electric trunking installation pictures | Electric Panel Installation Pictures | FR electric cable installation pictures | Multi storey building electric closets | Underfloor trunking pictures | Site-fabricated electrical trunking | Electrical Services Color Codes | Light switch installation pictures | Building’s electrical rooms layout | Electrical installation pictures
=================
These pictures were taken inside the Consumer HV Room of a new office building.
Picture 1 above shows the cable ladder connecting to the consumer HV switchgear panels.
Observe that there are four switchgear panels there.
On the cable ladders, there are only three HV cables. Is one of the HV switchgear panels kept as a spare?
Nope. Actually the supply authority’s HV Room is just next door to the consumer HV Room. The multi-core 11kV cable feeding supply to the consumer HV switchgears is run inside a cable trench connecting the two HV rooms. So it is not visible here.
To beginners in electrical installation works, observe carefully how the cable ladders are hung from the concrete slab using steel hanger rods. Observe also how close the spacing between adjacent hanger rods.
HV cables are heavy. The weight of the cables is one thing. There are also the bending forces of the cable when they are routed and bent along the cable ladders. At certain positions along the cable routes, the opposing bending forces of the cable ladders add to the weight of the cable itself.
What you can see in Picture 1 above are only very few cables. On many occasions in you career, you will see situations where cable ladders of the size shown in the picture sag. The forces and weight from the power cables can be that strong.
Picture 2 – Close up view of an angle iron support and the hanger rods
Observe how the angle iron support is supported at each end by a hanger rod.
Picture 3 – The cable ladder connecting HV switchgears to a transformer
Here the worker standing behind the transformer enclosure is doing the termination works of the 630 mm.sq. low voltage copper cables.
Recall that here we have four HV switchgear panels. One for the incoming cable from the supply authority switchgears in the room next door. The other three are the feeder cables for the consumers’ transformers.
In many designs, a consumer substation is designed to have separate rooms for HV switchgears and transformers. Here it has been designed to share the same room.
It does not really make much difference whether the rooms for both are shared or separate. The only real difference is the total space taken.
If separate rooms are used, it would take more space. In some installations, the space is expensive. Commercial buildings at prime areas of a big city are a classic example. Private owners count every dollar they spent on every functional space of the building. Many consider space taken by mechanical and electrical plants as a waste. So often design engineers end up with very little space to install their machines and equipment.
Here it is not so bad because it is a government office building.
The cable ladder shown in Picture 3 above provide a cable support for the HV cables from HV switchgear to a 1600 kVA transformer. This transformer serves the chiller plant behind the HV room.
The low voltage cables being terminated by the worker are also run on a cable ladder to go to the chiller plant LV switchboard.
Picture 4 – Cable ladder to 1000kVA transformers
This picture show the cable ladders to the other transformers in this substation.
Here you can see low voltage cables more clearly.
The transformers are 1000 kVA ones. While the 1600kVA transformer is dedicated to serve only the chiller plant (the main plant of the building’s centralized air-conditioning system), all other building electrical and mechanical loads including external loads (street lighting, carpark lighting, etc) are served by these two 11kV/415V transformers.
Observe how the low voltage cables coming out of the transformers are run of separate cable ladders to go to the main distribution switchboards in the LV Room at the other side of the wall.
Wall openings on the wall would later be sealed by an approved fire seal to prevent spreading of fire from one electrical room to the next.
Notice also the automatic fire suppression units (the red-painted round cylindrical objects mounted on the walls) installed at locations around the switchgear room. I will talk on the automatic fire suppression system in another post.
Copyright http://electricalinstallationwiringpicture.blogspot.com Cable ladder pictures
Picture 1 – Cable ladders at Consumer’s High Voltage Switchgears
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These pictures were taken inside the Consumer HV Room of a new office building.
Picture 1 above shows the cable ladder connecting to the consumer HV switchgear panels.
Observe that there are four switchgear panels there.
On the cable ladders, there are only three HV cables. Is one of the HV switchgear panels kept as a spare?
Nope. Actually the supply authority’s HV Room is just next door to the consumer HV Room. The multi-core 11kV cable feeding supply to the consumer HV switchgears is run inside a cable trench connecting the two HV rooms. So it is not visible here.
To beginners in electrical installation works, observe carefully how the cable ladders are hung from the concrete slab using steel hanger rods. Observe also how close the spacing between adjacent hanger rods.
HV cables are heavy. The weight of the cables is one thing. There are also the bending forces of the cable when they are routed and bent along the cable ladders. At certain positions along the cable routes, the opposing bending forces of the cable ladders add to the weight of the cable itself.
What you can see in Picture 1 above are only very few cables. On many occasions in you career, you will see situations where cable ladders of the size shown in the picture sag. The forces and weight from the power cables can be that strong.
Picture 2 – Close up view of an angle iron support and the hanger rods
Observe how the angle iron support is supported at each end by a hanger rod.
Picture 3 – The cable ladder connecting HV switchgears to a transformer
Here the worker standing behind the transformer enclosure is doing the termination works of the 630 mm.sq. low voltage copper cables.
Recall that here we have four HV switchgear panels. One for the incoming cable from the supply authority switchgears in the room next door. The other three are the feeder cables for the consumers’ transformers.
In many designs, a consumer substation is designed to have separate rooms for HV switchgears and transformers. Here it has been designed to share the same room.
It does not really make much difference whether the rooms for both are shared or separate. The only real difference is the total space taken.
If separate rooms are used, it would take more space. In some installations, the space is expensive. Commercial buildings at prime areas of a big city are a classic example. Private owners count every dollar they spent on every functional space of the building. Many consider space taken by mechanical and electrical plants as a waste. So often design engineers end up with very little space to install their machines and equipment.
Here it is not so bad because it is a government office building.
The cable ladder shown in Picture 3 above provide a cable support for the HV cables from HV switchgear to a 1600 kVA transformer. This transformer serves the chiller plant behind the HV room.
The low voltage cables being terminated by the worker are also run on a cable ladder to go to the chiller plant LV switchboard.
Picture 4 – Cable ladder to 1000kVA transformers
This picture show the cable ladders to the other transformers in this substation.
Here you can see low voltage cables more clearly.
The transformers are 1000 kVA ones. While the 1600kVA transformer is dedicated to serve only the chiller plant (the main plant of the building’s centralized air-conditioning system), all other building electrical and mechanical loads including external loads (street lighting, carpark lighting, etc) are served by these two 11kV/415V transformers.
Observe how the low voltage cables coming out of the transformers are run of separate cable ladders to go to the main distribution switchboards in the LV Room at the other side of the wall.
Wall openings on the wall would later be sealed by an approved fire seal to prevent spreading of fire from one electrical room to the next.
Notice also the automatic fire suppression units (the red-painted round cylindrical objects mounted on the walls) installed at locations around the switchgear room. I will talk on the automatic fire suppression system in another post.
Copyright http://electricalinstallationwiringpicture.blogspot.com Cable ladder pictures
Monday, July 18, 2011
Electrical grounding
I believe I have uploaded to this blog quite a number of pictures on electrical grounding. However, there is one work of the grounding system that I have always wanted to show the readers especially true beginners (i.e. students and young engineers). That is the process of exothermic welding.
Picture 1 – 25mm x 3mm grounding copper tape permanently bonded to ground using exothermic welding
This ground rod and the inspection chamber are in place. The grounding copper tape has been permanently bonded to the ground rod.
The inspection chamber has been placed tentatively at the approximate finished ground level.
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RELATED ARTICLES: Exothermic welding: Cable to cable connections | Substation main earth bar pictures | Electrical Grounding Electrode Pictures | Switchboard earthing pictures | Lightning roof conductor installation | Lightning Earth Rods Installation | Temporary Electrical Earthing Pictures | Electrical installation pictures
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Picture 2 – A closer view of the exothermic welding.
Personally I would prefer all grounding connections inside inspection chambers to be of the compression type (eg. using brass clamps). That is the purpose of the chamber, so that the maintenance people can inspect the grounding connections and do some work to improve the grounding resistance if and when necessary.
If the grounding resistance has deteriorated over time (i.e. the resistance to earth gets higher), then maybe we need to add one or more grounding electrodes and loop them to the existing grounding network.
The “looping” of the new electrodes to the existing ones would have been done inside this inspection chamber.
If the existing connections inside the chamber use exothermic welding such as that in Picture 2 above, connecting new earthing conductors here can be difficult.
Having said that, it should be acknowledged that under certain circumstances it might be better to have a permanent bonding. Exothermic bonding is a form of permanent bonding and it is maintenance-free.
In fact, with a properly carried out exothermic welding, the inspection chamber may not even be necessary. Some engineers may disagree with that, but that is how I think.
The above connection at the inspection chamber was already completed when I inspected it. Just for the purpose of showing it to readers of this blog, I have asked the electricians to make another joint so I can take some pictures. They are shown below.
Picture 3 – The grounding conductor and electrode before exothermic welding
This electrode was just another electrode not far from the one in Picture 1. There was no particular reason that I chose this one for the demonstration.
Maybe it was just because the top of the electrode was protruding quite a few inches above the expected finished ground level.
I guess I wanted to show that the driven electrode needed to be cut first before the exothermic welding process was carried out.
Picture 4 – A close-up view of the ground rod and copper tape conductor
Picture 5 – Cutting the excess top part of the electrode.
Keep in mind that later the top of the rod and joint between the rod and the copper tape should be inside the inspection chamber.
The concrete inspection chamber itself would have a removable concrete cover.
Therefore the top of the ground rod should be just below the concrete cover when the cover is in place.
The whole of the chamber and the cover should be flushed to the finished ground level, or flushed to the finished road level if it is installed under road.
Picture 6 – Preparing the top of electrode to accept the copper tape.
If you look at Picture 2 again, you can observe that the copper tape is like “standing” or “slicing” the electrode. Some electricians prefer to put the tape flat on top of electrode.
I think it makes no difference either way. It’s just that the opening at the mould (you will see the mould soon) should be cut accordingly. Electricians do not normally make the mould themselves. They order them from electrical shops.
In the above picture, the two workers were making a shallow slit at the top of the electrode. It was cut small enough to just “park” the copper tape into it.
That would give the joint a stronger mechanical strength, they said. I doubt that, but then I didn’t think it would much difference either way.
Picture 7 – A closer view
Picture 8 – The workers trying to park the copper tape onto the ground rod.
Picture 9 – A closer view
Picture 10 – Now the worker places the mould to the joint and encloses it.
The work you see here requires is not difficult, but it requires at least two or three persons. Now the workers place the mould in such a way so that it encloses the joint between the copper tape and the copper-jacketed steel earth rod.
Picture 11 – Now the mould is in place.
Observe how the mould is constructed with a handle that can grip both conductors to be jointed.
Picture 12 – A closer view of the mould enclosing the joint.
By now even a first time viewer should be able to make a conclusion that a different mould would be necessary if two other different types of conductors were to be jointed.
Picture 13 – Tying the mould with a metal wire for extra strength.
Here the workers tried to give the grip of the mould over the joint an extra strength by tying it with a metal wire.
Picture 14 – Filling the mould with an explosive powder mixture.
Now the mould is being filled with a type of explosive powder mixture. Contained in the mixture also is a form of copper material so that during the quick combustion the copper elements melted onto the joint and forms a permanent joint.
It is similar to jointing two different pieces of concrete blocks with liquid concrete. After the liquid concrete has hardened, the two concrete blocks would become one larger block. The difference is that the liquid concrete takes much longer to harden. Whereas here the copper element in the powder mixture melts during the explosive combustion and then hardened. So the process here is very much quicker.
Picture 15 – A closer view of the powder mixture.
Picture 16 – Preparing a gas torch to ignite the powder.
Picture 17 – The gas torch
Picture 18 – BOMB! Take cover!!
I do not remember exactly what I was doing, but I did not have my camera ready when the worker ignited the explosive powder in the mould. So I was not able to catch the bid smoke during the hard combustion.
Actually during the whole process, I was have a visitor to the site who wanted to see the exothermic welding process. So while I was taking pictures for this blog, I was also sort of “entertaining” the visitor, and missed the big smoke.
If you click on the picture to make it larger, you may still be able to “feel” the remaining smoke there. I am so sorry about that. I will try to catch the big smoke some other time.
Picture 19 – The explosive powder has been spent.
Now the mould seems to be empty. After the combustion, the mould had to be left there for a few minutes so it can get cooled enough before anyone can try to pry it open.
Picture 20 – Untying the metal wire around the mould.
Picture 21 – Now the mould has been taken off.
Picture 22 – A closer view of the joint after the mould has been taken off.
I heard someone actually chuckled and said “ Wow! It’s like a cup cake!”.
I don’t think it is in any way resembling a cup cake.
However, after so many years seeing it done, I always have that little excitement inside whenever a new mould and powder mixture is used to make exothermic joint.
Because when the mould is cracked open, the resulting joint piece is like a new artwork.
Picture 23 – Someone knocked off the still hot copper flakes off the joint.
Picture 24 – A beautiful exothermic joint
Do I need to say more?
See you guys around.
Copyright http://electricalinstallationwiringpicture.blogspot.com Electrical grounding
Picture 1 – 25mm x 3mm grounding copper tape permanently bonded to ground using exothermic welding
This ground rod and the inspection chamber are in place. The grounding copper tape has been permanently bonded to the ground rod.
The inspection chamber has been placed tentatively at the approximate finished ground level.
=================
RELATED ARTICLES: Exothermic welding: Cable to cable connections | Substation main earth bar pictures | Electrical Grounding Electrode Pictures | Switchboard earthing pictures | Lightning roof conductor installation | Lightning Earth Rods Installation | Temporary Electrical Earthing Pictures | Electrical installation pictures
=================
Picture 2 – A closer view of the exothermic welding.
Personally I would prefer all grounding connections inside inspection chambers to be of the compression type (eg. using brass clamps). That is the purpose of the chamber, so that the maintenance people can inspect the grounding connections and do some work to improve the grounding resistance if and when necessary.
If the grounding resistance has deteriorated over time (i.e. the resistance to earth gets higher), then maybe we need to add one or more grounding electrodes and loop them to the existing grounding network.
The “looping” of the new electrodes to the existing ones would have been done inside this inspection chamber.
If the existing connections inside the chamber use exothermic welding such as that in Picture 2 above, connecting new earthing conductors here can be difficult.
Having said that, it should be acknowledged that under certain circumstances it might be better to have a permanent bonding. Exothermic bonding is a form of permanent bonding and it is maintenance-free.
In fact, with a properly carried out exothermic welding, the inspection chamber may not even be necessary. Some engineers may disagree with that, but that is how I think.
The above connection at the inspection chamber was already completed when I inspected it. Just for the purpose of showing it to readers of this blog, I have asked the electricians to make another joint so I can take some pictures. They are shown below.
Picture 3 – The grounding conductor and electrode before exothermic welding
This electrode was just another electrode not far from the one in Picture 1. There was no particular reason that I chose this one for the demonstration.
Maybe it was just because the top of the electrode was protruding quite a few inches above the expected finished ground level.
I guess I wanted to show that the driven electrode needed to be cut first before the exothermic welding process was carried out.
Picture 4 – A close-up view of the ground rod and copper tape conductor
Picture 5 – Cutting the excess top part of the electrode.
Keep in mind that later the top of the rod and joint between the rod and the copper tape should be inside the inspection chamber.
The concrete inspection chamber itself would have a removable concrete cover.
Therefore the top of the ground rod should be just below the concrete cover when the cover is in place.
The whole of the chamber and the cover should be flushed to the finished ground level, or flushed to the finished road level if it is installed under road.
Picture 6 – Preparing the top of electrode to accept the copper tape.
If you look at Picture 2 again, you can observe that the copper tape is like “standing” or “slicing” the electrode. Some electricians prefer to put the tape flat on top of electrode.
I think it makes no difference either way. It’s just that the opening at the mould (you will see the mould soon) should be cut accordingly. Electricians do not normally make the mould themselves. They order them from electrical shops.
In the above picture, the two workers were making a shallow slit at the top of the electrode. It was cut small enough to just “park” the copper tape into it.
That would give the joint a stronger mechanical strength, they said. I doubt that, but then I didn’t think it would much difference either way.
Picture 7 – A closer view
Picture 8 – The workers trying to park the copper tape onto the ground rod.
Picture 9 – A closer view
Picture 10 – Now the worker places the mould to the joint and encloses it.
The work you see here requires is not difficult, but it requires at least two or three persons. Now the workers place the mould in such a way so that it encloses the joint between the copper tape and the copper-jacketed steel earth rod.
Picture 11 – Now the mould is in place.
Observe how the mould is constructed with a handle that can grip both conductors to be jointed.
Picture 12 – A closer view of the mould enclosing the joint.
By now even a first time viewer should be able to make a conclusion that a different mould would be necessary if two other different types of conductors were to be jointed.
Picture 13 – Tying the mould with a metal wire for extra strength.
Here the workers tried to give the grip of the mould over the joint an extra strength by tying it with a metal wire.
Picture 14 – Filling the mould with an explosive powder mixture.
Now the mould is being filled with a type of explosive powder mixture. Contained in the mixture also is a form of copper material so that during the quick combustion the copper elements melted onto the joint and forms a permanent joint.
It is similar to jointing two different pieces of concrete blocks with liquid concrete. After the liquid concrete has hardened, the two concrete blocks would become one larger block. The difference is that the liquid concrete takes much longer to harden. Whereas here the copper element in the powder mixture melts during the explosive combustion and then hardened. So the process here is very much quicker.
Picture 15 – A closer view of the powder mixture.
Picture 16 – Preparing a gas torch to ignite the powder.
Picture 17 – The gas torch
Picture 18 – BOMB! Take cover!!
I do not remember exactly what I was doing, but I did not have my camera ready when the worker ignited the explosive powder in the mould. So I was not able to catch the bid smoke during the hard combustion.
Actually during the whole process, I was have a visitor to the site who wanted to see the exothermic welding process. So while I was taking pictures for this blog, I was also sort of “entertaining” the visitor, and missed the big smoke.
If you click on the picture to make it larger, you may still be able to “feel” the remaining smoke there. I am so sorry about that. I will try to catch the big smoke some other time.
Picture 19 – The explosive powder has been spent.
Now the mould seems to be empty. After the combustion, the mould had to be left there for a few minutes so it can get cooled enough before anyone can try to pry it open.
Picture 20 – Untying the metal wire around the mould.
Picture 21 – Now the mould has been taken off.
Picture 22 – A closer view of the joint after the mould has been taken off.
I heard someone actually chuckled and said “ Wow! It’s like a cup cake!”.
I don’t think it is in any way resembling a cup cake.
However, after so many years seeing it done, I always have that little excitement inside whenever a new mould and powder mixture is used to make exothermic joint.
Because when the mould is cracked open, the resulting joint piece is like a new artwork.
Picture 23 – Someone knocked off the still hot copper flakes off the joint.
Picture 24 – A beautiful exothermic joint
Do I need to say more?
See you guys around.
Copyright http://electricalinstallationwiringpicture.blogspot.com Electrical grounding
Friday, July 15, 2011
Compound lighting storage yard
I took a few pictures of the storage area for compound lighting parts at a project site recently. With these pictures I think I have explained the whole system of compound lighting in this blog. So this post wraps up the topic of compound lighting. Of course, if I find more pictures that I think readers would be interested in, I will attach a link to this post also.
Picture 1 – 10 meter light poles: the lower piece
This is the lower part of 10-meter lighting poles. The upper pieces are shown in Picture 2 below.
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Picture 2 – 10 meter lighting poles: the upper piece
As you can see, these poles are still tied into bundles. These are how they get packaged and transported in lorries or trucks.
As you may already know, lighting poles are usually made of hot-dipped galvanized steel materials or some form of fiber. In this case, it is hot-dipped galvanized.
These materials are chosen for their resistance to the effects of rough weather and resistance to corrosion.
That is why when they are delivered to a construction site, it is usual to see that they are sort of “dumped” to the ground, and be left there until the time to erect them to the concrete foundation.
Picture 3 – Compound lighting concrete foundation
Observe the four anchor bolts that are visible on top of the concrete foundation. These component can also be found at the storage yard. See Picture 4 below.
Picture 4 – Anchor bolts
Picture 5 – Control gear access door
This is the access door for the light pole control-gears. I am not trying to promote any particular brand here. However, observe the design of the hinch for the control door and also the special shape of the door locking screw.
Picture 6 – Access door hinch
Picture 7 – Access door lock
Picture 8 – Complete assembly of an 8-meter compound lighting pole
Finally, the above picture shows the complete assembly of an 8-meter light pole.
Copyright http://electricalinstallationwiringpicture.blogspot.com Compound lighting storage yard
Picture 1 – 10 meter light poles: the lower piece
This is the lower part of 10-meter lighting poles. The upper pieces are shown in Picture 2 below.
================= RELATED ARTICLES: Electric Cable Drum Pictures | Underground street light cables | Compound Lighting Installation Pictures | Feeder pillar single line diagram | Bollard light pictures | Feeder pillar hazard pictures | Compound lighting foundation size | Electrical installation pictures
=================
Picture 2 – 10 meter lighting poles: the upper piece
As you can see, these poles are still tied into bundles. These are how they get packaged and transported in lorries or trucks.
As you may already know, lighting poles are usually made of hot-dipped galvanized steel materials or some form of fiber. In this case, it is hot-dipped galvanized.
These materials are chosen for their resistance to the effects of rough weather and resistance to corrosion.
That is why when they are delivered to a construction site, it is usual to see that they are sort of “dumped” to the ground, and be left there until the time to erect them to the concrete foundation.
Picture 3 – Compound lighting concrete foundation
Observe the four anchor bolts that are visible on top of the concrete foundation. These component can also be found at the storage yard. See Picture 4 below.
Picture 4 – Anchor bolts
Picture 5 – Control gear access door
This is the access door for the light pole control-gears. I am not trying to promote any particular brand here. However, observe the design of the hinch for the control door and also the special shape of the door locking screw.
Picture 6 – Access door hinch
Picture 7 – Access door lock
Picture 8 – Complete assembly of an 8-meter compound lighting pole
Finally, the above picture shows the complete assembly of an 8-meter light pole.
Copyright http://electricalinstallationwiringpicture.blogspot.com Compound lighting storage yard