M & E Coordination

The few pictures that I show in this post is a demonstration of what can happen when proper coordination drawings are not produced prior to the commencement of the mechanical and electrical services installation in a multi-storey building.

Picture 1 – Improvised installation of electrical trunking, air-conditioning ducts, fire protection pipe work and a floor beam



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Somewhere among my previous posts, you can find examples of good coordination between the mechanical and electrical services installation.

However, here I wish to show you the opposite side of it. The above is not the worst case examples. I have plenty of pictures showing much worse scenarios which I will show you in future posts.

A reminder for the beginners in electrical installation works: Learn from the mistakes that other people have done and plan your work accordingly.

This is a very expensive lesson if you have to learn it from personal experience because rectifications, relocation or corrections in large installations can be very expensive and time consuming.

I do not plan to make this a long article. Regular visitors to this blog may have noticed that I have not been posting for quite a number of months.

A few have been asking me to continue posting articles and adding more topics.

So today I am back and you can expect to see some more pictures of electrical installations, good and bad.

There are readers who condemned a few of the pictures that I use to explain something.

They seem to have the opinion that using pictures with bad installation practices is like promoting bad installation practices.

With all due respect to their experience and expertise, I beg to differ on this matter and I think many would agree with me.

I also wish to remind the readers that none of the electrical installation works published here is my handiwork, whether the good ones or the bad ones. I did not do the wiring work; I did not do the trunking installation, etc.

I might have been the inspector with the responsibility to inspect or audit some the installation works.

However, when I show a picture, it does not necessarily mean that I say “this wiring work is a good example”. Or it is bad, unless I specifically say so.

It only means that there is something that the readers can learn from the picture.

Please bear in mind that different readers may learn different lessons from one single picture.

One of the primary objectives of this blog is to educate common people in how electrical installations work in real life. That is why I use “real” pictures.

In real life, the “real installations” (such as one’s own house wiring) are often “not that neat” and not that pretty.

It is very easy for me to show you pictures of neat and orderly house and office installations. I work in the construction business and I have tons of pictures of neat installations like that.

However, people often find it hard to understand the actual wiring in their own house or their own small offices because in most cases the wiring works are not new. They have been modified and they have been tampered with by people who either didn’t know enough or didn’t care enough about safety, or he tried to make the wiring works at a very low cost.

Whatever the reasons for the bad practices, the occupant who inherit the unit is faced with a wiring “system” that is hard to understand and is full of bad practices.

It is for this very reason that I use these pictures to explain how the wiring works. They are “real”.

That is all I have time for today. Enjoy the pictures and see you again in the next post.

Picture 2 – Electrical trunking and air-conditioning ducts



Picture 3 – Sprinkler pipes and trunking



Picture 4 – Telephone trunking, electrical and aircond duct



Picture 5 – Sanitary piping and domestic water pipes above electric trunking



Picture 6 – Sanitary pipes above electric trunking



Picture 7 – Trunking below sprinkler pipes



Picture 8 – Trunking below water piping



Picture 9 – Water pipes above trunking



You can see more pictures of electrical installation at this post, Electrical installation pictures.

Copyright http://electricalinstallationwiringpicture.blogspot.com M & E Coordination

Standby electric generator pictures

Today I am sharing with you a few pictures of a standby electric generator.

Picture 1 – 1000 KVA Standby Diesel Generator



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The generator room that houses this genset was not very large. All the equipment and support services for the standby diesel genset system were nicely laid out and installed, but there was not too much spare inside the room.

That was why I could not get a good overall picture of the generator unit.

Why do we a standby electrical generator?

No building of a significant size can be safely occupied without at least a small back-up electric generator installed.

The most important reason is the protection of lives in the case of fires. I think all fire departments in the world make the standby emergency generator a mandatory requirement for buildings with areas exceeding a certain size, or if the building exceeds a certain height.

Why diesel generators?

Oil is still a principal source of energy in our world today.

Even though for the past few years world government seemed to have put much greater emphasis on other sources of energy such as the solar energy, etc, we are still very much dependent on the fossil fuels as we have been for the past 100 years or so I think.

Because of that, diesel engine driven gensets system have been used on a large scale as a back-up electrical system to the public electricity supply.

These systems usually comprise of a diesel engine coupled to an electric alternator (also called electric generator) on a single chassis or a structural frame. Switchgears and control gears for operation, protection and instrumentation are also usually incorporated into the system.

The generator is set up so it is automatically started from a 12 V or 24 V batteries when the public mains supply fails. Then it takes over the electrical loads and shut down again after the mains electricity supply returns.

Usually not all of the building’s electrical loads are backed-up by this standby supply. Only the loads that are classified as part of the building’s fire protection system, and other loads that are categorized during the design as essential loads.

Picture 2 – Part view of the genset showing the alternator



It would be better of I can show the whole genset unit in a single picture but I can’t.

Here is the back end of the generator unit (assuming we can call the front of the radiator as the front). The diesel engine is coupled to this alternator (or electric generator), the part of the system that produces the electricity.

Notice on top of the alternator there are four flexible conductor connections.

Engines are machines that vibrate a lot. Everything that is connected to the diesel engine and the alternator should have considered the vibration in their design and installation. Picture 3 below shows one of the rubber absorbers installed below the engine chassis to absorb the effects of vibration between the genset unit and the building floor.

Picture 3 – Rubber vibration absorber



Picture 4 – Engine exhaust suspension hanger



Picture 5 – Spring absorber for the engine suspension hanger



As you can see from the above pictures, a lot of cost and efforts have been spent to handle the effects from the engine and alternator vibrations.

Picture 6 – Engine exhaust and silencer



An engine powered by fossil fuels need to exhaust the waste combustion gases. The picture above shows the exhaust gas pipe penetrating the generator room wall to discharge the hot gas outside.

The position of the outlet outside the building should be high enough above any possible walking pedestrians and passenger cars nearby.

Picture 7 below shows the position and height of the engine exhaust pipe outside the generator room wall.

Picture 7 – Engine exhaust and radiator exhaust outside the generator room wall



Both the engine exhaust and the hot air from the the radiator fan are shown in the above picture.

It happens that the side of the wall is right above the access route to the basement level of the building. Therefore, the engine exhaust is very well above the recommended level.

However, the radiator exhaust is at ground level.

But then the location of the radiator is not at any path way. In fact, a planter box has been constructed right in front of the radiator exhaust.

This would help not only keep the passer-bys away from the front of the exhaust grill, but also give a degree of camouflage which would make many architects a little bit happier.

I have a few more pictures to show you on this genset installation, but I am running late to a meeting now.

So I will upload the other pictures after a few days.

Visit this post, Electrical installation pictures, to see other photos that I have uploaded to this blog.



Copyright http://electricalinstallationwiringpicture.blogspot.com Standby electric generator pictures

FR electric cable install picture

The following few pictures show the installation of FR electrical cables. There is nothing special about the installation of the fire-rated (FR) cables. Even though these cables are a direct replacement of mineral insulated copper cables (MICC) for high-rise buildings, the installation here is the same as for normal XLPE or PVC-insulated cables.

Picture 1 – FR cables installed on tray



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This picture shows two circuits employing FR electric cables installed on a vertical cable tray. These cables were taken in a cable riser at a multi-storey building.

All these cables are single-cores. The circuit on the right (with the smaller cables) was supplying the lift motor room at the roof level of the building.

The copper tape on the right edge of the vertical cable tray is the common earth and it is connected to the main electric grounding bar at the LV Room on the ground floor of the building.

The LV Room houses all main switchboards (MSB’s) for the building.

The circuit on the left edge of the cable tray was supplying two fan rooms, which were also at the roof level.

The loads of the fan rooms were mostly electric driven motors that run fire protection fans. These include smoke spill fans, staircase pressurization fans, etc.

These fan loads are significantly large. That is why the cables are of bigger size than those for the lift motor room electrical panel.

The color of FR cables

You can see in the picture that all the outer sheath of the FR cables are red colored.

I think the manufacturer can manufacture the cables to any color you wish. In this project the red color has been chosen because these FR cables supplies the equipment of the building’s fire fighting system.

Red is the standard color code for all fire fighting and fire protection systems and equipment as far as I know.

Fire sprinkler pipes, wet riser pipes, hose reel pump control panels, etc are all painted with red color.

Standby electric generators are part of the fire protection system

All the FR cables in picture 1 are supplied from the Essential MSB (EMSB) inside the LV Room at the ground floor.

The electric supply of the essential MSB in turn is backed by the standby electric generator of the building.

For readers with minimal background knowledge in the design of high-rise buildings, a standby electric generator is part of the fire protection system of a high rise building. Many fire fighting equipment and systems depend on the electricity supplied by this generator (or generators, often more than one electric generator are needed when the building’s total floor areas are very large, or if the building complex is spread over a very wide land area).

Fire lift is a classic example. Even though lift are designed as a means of vertical transportation for multi-storey buildings, a minimum of one lift is required to be designed and equipped as a fire fighting lift.

That means to say one of the lift will be used by the firemen to fight fire during fire emergency.

That is why the cables that supply the lift electrical panel should have the properties that can withstand fire condition for a few hours. That is also the reason the cables supplying the lift panels in picture 1 are colored red.

Essential supply cables are also colored red

Because electricity supply from the standby diesel generators is part of the building’s fire protection system, it follows that all cables from the generators must be colored red. This is assuming that the building’s color code for fire fighting equipment is red.

However, the supply from the standby generators is not only used for the fire protection. There are also other types of equipment in the building that need supply from the generators for other reasons.

These are equipment, lighting and socket outlets that need to run even when the mains supply from the public supply network is down.

We call the supply to these types of equipment “Essential Supply”. It is an essential electricity need of the building. Which equipment, lighting and power sockets need to be provided with the essential supply is usually defined by the owner of the building, assisted by professional architects, engineers and building managers. That is why the advice of at least one of these professionals is always needed during the planning of any new building.
Even though the is not fire fighting equipment connected to a circuit supplying essential supply, the supply cables are usually colored red. This is the common practice.

FR cable installation pictures

The foregoing general brief was given to fill in the gaps some readers may have when looking at the pictures of FR cable installations in this post and in other posts here.

I would need a separate and dedicated post to discuss the fire-related electrical systems in building works, which I may actually do some time in the near future. However, for now let just stick to the pictures.

Picture 2 – More fire-rated (FR) cables



Here there are more FR cables in the electrical riser.

Actually, this electrical riser is at the same building, but it is in a different riser room.

This building actually has two tower blocks: one tall and one a lower tower attached to each other.

Most of the mechanical plant and fire-related equipment for the both building towers are located at the roof of the lower tower. The cables on this cable riser tray supply emergency power to the lower roof.

That is the reason you seem more FR cables here.

Separate supply cables for each fire fighting system

A note for genuine beginners: it is usually a common practice to install a totally separate supply circuit for each system of fire fighting equipment and other mechanical systems from the Essential MSB (EMSB) at the LV Room.

Even the earthing cables are usually independent. That is why you can see the smaller green cables bunched together with each of the four circuits in picture 2.

However, you do not see the green earth cables in Picture 1 even though there are 2 separate circuits going up to the roof.

You see, the designers were not being very strict here.

I personally supervised the installation in this project, but it was a design-and-build contract. In this kind of contract, the professional design consultants are part of the main contractor’s team.

Because of that, the consultants must support the main contractor’s continuing effort to reduce costs and maximize profits.

They call this “value engineering”.

I apologize for the “negative tone” there, but I have been involved in many “turnkey contracts” and “design-and-build contracts” either as design engineers, consultant’s project managers and construction supervision engineers.

I think I have earned the right to insert the “negative tone” there.

Picture 3 – Normal supply cables



This picture shows a circuit employing normal supply cables on a separate vertical cable tray alongside the cable tray carrying the FR cables.

Notice the 3mm x 25mm earthing copper tape clipped to the cable tray along the single-core cables.

The normal supply cables here uses XLPE type cables for all submain cables. Only the final wiring circuits were allowed to use PVC insulated cables.

What is a “submain” cable?

I bold this item for the benefit of beginners in electrical installation works and building services engineering.

A submain cable is a cable that feeds supply from the main distribution equipment of an electrical system to an electrical panel that further distributes that electric power to current-using equipment or other electrical panel downstream of the distribution hierarchy.

The term can actually be used rather loosely.

In contrast to this term, a final wiring circuit cannot be called a submain cable even though the circuit may use exactly the same type and size of cables.

A set of cables supplying power ‘into’ the main distribution board are usually called main cables. I think that is why the distribution cables coming out of the main switchboard are called submain cables.

There is nobody out there going around enforcing rules about what you should call these cables. It is just a widely practiced way of categorizing these cables in real installations. If you call them the way other people in the industry call them, then you are using the same language.

If not, other people may get confused about what you were trying to say. That’s all.

Picture 4 – FR cable termination to busduct feed in box



This picture shows the termination of a busduct riser.

A busduct is a set of electrical conductors (usually copper or aluminium conductors) enclosed inside metal trunking.

The assembly is usually factory-manufactured and sold in ready-made length complete with integral earthing conductors.

You only need to purchase the number of lengths necessary to cover the distance from the source of supply to the destination.

Bends and angle pieces are also available from the manufacturers.

If you wish to know more about busduct installations, read this post, Electrical busduct installation pictures. There are more pictures there too.

Picture 5 – Fixing of the FR cables to cable tray



There is nothing special about the cable tie used to fix the FR cables to the cable tray. It is just the same type used to tie normal supply cables (i.e. PVC cables or XLPE cables).

Steel bolt and nuts are used to hold and tighten the steel cable tie to the tray.

Picture 6 – Copper tape fixing to the cable tray



This is just a closer view to show how the 3mm x 25mm earthing copper tape is fixed to the cable tray.

It is actually not necessary to use separate copper tape or the green earth cables to provide the electrical grounding for the electrical system.

The steel wire armor of multi-core submain cables can also be used to provide the electric grounding path.

Proper calculations should be done however, in order to ensure the cross-sectional area of the conductor is adequate for the protection system to operate properly. Also to ensure the requirements of the relevant codes are complied with.

Using separate 3mm x 25mm copper tapes is widely practiced in good installations because it is easy to monitor the quality of the earthing system and minimize the possibility of the contractor doing “value engineering” to this most important part of shock protection in an electrical installation.

That is all the time I can spare today for blogging.

I will see you again in the next post.

If you need more pictures, just visit Electrical installation pictures. There are links there that will take you the various posts with the pictures you are looking for.


Copyright http://electricalinstallationwiringpicture.blogspot.com FR electric cable installation pictures

Feeder pillar single line diagram

Today I will show the readers a simple schematic diagram of a compound lighting feeder pillar. It is for those who need to know a few basics of a compound lighting system in order to carry out other tasks such as architectural landscape design and costing works, etc.

There are also a few pictures of feeder pillars so the single line diagram will make some sense. If you need to allocate some space for the feeder pillar plinth, then I have already uploaded a few diagrams towards the end of this post. They should give you enough information to solve the technical problems.

Diagram 1 – Single line diagram of a small feeder pillar for compound lighting




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A feeder pillar single line diagram is similar a house electrical panel schematic diagram with the addition of an automatic time switching circuit added.

In the single line diagram, the time switching circuit is the circuit portion towards the top left corner of the dotted rectangle box. The sub-schematic is shaded into lighter grey.

Diagram 2 – Timer switch circuit



There are three items I wish to highlight to readers at the time switching circuit: the time switch, the contact coil and the “SWITCH BY PASS”.

The TIME SWITCH

First, the time switch. This is drawn with a symbol of a circle with the “TS” letters inside it.

A time switch is a component that is common to all street lighting and compound lighting. Its purpose is to eliminate the need for human actions to turn “ON” and “OFF” the lighting at the intended operation hours.

For example, the external carpark of a shopping complex may need to be lighted up at 7 every evening and be turned off at 3 A.M.

So this ON and OFF times can be set at the time switch inside the feeder pillar.

A human operator may miss the exact time one day, which can leads to complains by customers, but a machine would not forget. They may break down, but a properly cared machine can be much more reliable than human most of the time.

In large installations, even indoor lights are sometimes installed with similar automatic timers. It is not just for good service, but also to reduce operating costs as the setting of the timer can be authorized to only selected individuals of the organization.

One hour of delayed switching off the lights every night can mean significant additional dollars monthly on electricity bills in large installations.

The SWITCH BY PASS, or MANUAL BYPASS SWITCH

Another important component here is the normally open switch that is labeled SWITCH BY PASS in the single line diagram.

In many drawings, it is called MANUAL BYPASS SWITCH, which I think is more appropriate and more accurate. But one of my draughting lady tends to prefer SWITCH BY PASS label so much that I need to let her have her own way.

The manual bypass switch is used for maintenance or trouble-shooting works. It simply bypass the time switch to ON or OFF the external lighting or street lighting.

For genuine beginners, observe that the bypass switch is connected in parallel with the contacts of the timer relay (Diagram 2 above). With this configuration, either contact in a closed position would energize the contact coil and turn on the external lights.

Often the switch is also the key-operated type so that the ability to bypass the timer can be restricted to only authorized individuals.

The contact coil

This is the third component in the time-switch circuit.

The load currents to the lighting cables are usually higher than the current that the timer contacts can handle. Therefore, another coil with heavy current contacts need to be provided to switch the heavy currents.

That is the purpose of the coil with a symbol of the circle with the “C” in it.

Observe the dotted line connecting the coil to the three contacts at the lighting load circuit.

That is all I wish to say on the timer switch circuit today. For electrical-based readers, the above explanations are never necessary. However, for no-electrical readers, these details on the schematic diagram would probably confuse many of them

Now let’s go through a few more components inside the feeder pillar cubicle that may confuse the readers from understanding the simple single line diagram.

The cubicle lighting

Towards the right edge of the dotted rectangle, there is a fuse labelled “20A SPN S/F”. You may not see this extra component inside a normal distribution board.

It is used to supply a fluorescent light inside the feeder pillar. As you know, the feeder pillars are installed outside. Any problem to the compound lighting would probably be noticed at night, when the lights are supposed to function.

Because of that, maintenance, trouble-shooting or repair works need to be done in the dark outside. The lighting from the compound lights would not be enough for work inside the feeder pillar. Additional light lighting is needed and that is what the fluorescent light fitting is for.

The socket outlet is also provided for the same purpose (i.e. to operate the tools for the maintenance work).

These are the accessories for the street light feeder pillar or compound lighting feeder pillar.

The timer switch circuit is actually a control circuit.

Other that that, the circuit schematic is almost similar to a simple house schematic.

The main schematic

Now let me give a short brief on the main schematic, the power circuit of the system.

As explained above, the dotted line rectangle represents the physical area of the feeder pillar cubicle.

Components and symbols located inside the dotted rectangle means they are located inside the metal cubicle. That is how to interpret an electrical diagram of this type.

The electric supply is taken from the Consumer Main Switchboard as shown at the lower part of the diagram.

A short introductory brief on armored electric cables

One length of underground armored cable is used. Underground means the cable is installed inside the ground about 3 ft below the surface.

Armored cable cost much more because of the steel wire armor protecting the cable from physical damage. The letters SWA in the cable tag “XLPE/SWA/PVC” is an acronym for “steel wire armor”.

“XLPE” at the front means the insulation of the cable conductor. When we say a cable, the terminology is actually not precise enough.

In this case, inside the incoming supply cable there is actually 4 inner cores each with an electrical insulation. Therefore, each of the four insulated inner cores (the inner core is usually made of either copper or aluminium) is a complete electrical cable by itself.

The four of them are bunched together to make it easier to run and it can reduce the cost. We can actually use 4 independent cables instead of one cable with 4 inner insulated cores.

The XLPE label mentioned above indicates the type of insulation of each of the inner cores.

When these cores are bunched together in a bunch like these, an outer insulation is again extruded or layered over the whole bunch, making it look like a single cable. It is actually 4 cables that are bunch together.

The outer insulation is called outer sheath.

If this cable is to be installed underground, it is always better and always considered necessary to provide something strong over the cable in case an excavation work accidentally hits it.

That is why the steel wire armor wrapped around the cable spirally all along the cable length. The armor protects the cable physically.

Then in order to protect the armor against corrosion and other degradation, another layer of insulation is applied over the steel wire armor. Most of the time, it is of PVC (poly vinyl chloride) materials.

That is the label “PVC” on the right of the cable tag.

I did not finish the XLPE part, did I?

What is XLPE?

The XLPE is just like the PVC, but is more expensive and of better quality. That is why it is used only at the inner core of the cable. The PVC material can be used instead of the XLPE, and it will work just fine.

But with XLPE, the inner cores can usually carry higher current for the same inner core size.

I know many readers already now this, but I always wanted to put it down somewhere so I can just give a link whenever an issue requires a further explanation on this cable topic.

What is 1 – 25 SQ. MM. / 4C?

“4C” – I just explained above, the 4 inner cores. If there are 5 or 3 cores inside, then it would have been 5C or 3C accordingly.

“25 SQ. MM.” – I mentioned about the size of each inner core, the copper or aluminium material underneath the XLPE insulation. This is the size. It is always in the form of net or real cross-section area. This means if an inner core is constructed of several smaller cylindrical copper wires, then the total cross-section area of those individual wires is taken and used to indicate the size in square millimeters.

I am following the British or European Standards here.

“1 – “ … well this mean one length of the 4-core cable is used here. We can use 2 lengths which will give us 8 cores of same sizes. They are installation conditions that may force us to do that, which is a more advanced topic. In that case, it would have been written like this:

“ 2 – 25 SQ. MM. /4C XLPE/SWA/PVC”.

That is all about the incoming cable.

The feeder pillar isolation switch

“60A TPN MCCB” – this is the isolation switch. The type of switch used is MCCB (moulded case circuit breaker).

So this switch is also a circuit breaker. It can automatically switch OFF when there a fault inside the feeder pillar cubicle or the cables going to the light poles.

You can actually use a switch and a fuse instead of the MCCB. That is the protection used to supply the cubicle fluorescent light explained above.

The outgoing circuit protection

Going downstream of the power flow path, you can see the outgoing circuit breakers (i.e. 20A SPN MCB) that are used to protect the cables going out to the light poles.

Six MCB’s are installed here.

Three are spares however. No cable is connected to the spare MCB’s even though there is a red line drawn to each one of them. This is the practice when drawing these types of electrical diagrams.

Each of the three MCB’s that are electrically loaded (they have electrical loads i.e. the lights connected to their outgoing cables) has 6 compound light fixtures connected to it.

Each of the fixtures is 70 watt. So we have 6 x 70 = 420 watt connected to a 20A circuit breaker. That is how to read the diagram.

The type of the compound light fitting is HPSV (high pressure sodium vapor).
(UPDATE: A low-pressure sodium type of street light or compound lighting would give you the yellowish light like those seen on the highway. Not a nice color but this type is very energy efficient.
But the high-pressure sodium vapour (HPSV) type that is used here has a good "color rendering". This is the terminology lighting people use to say that the colors produced by a lighting fixture allow human to distinguish different colors easily and correctly.
The low-pressure sodium lamp as mentioned earlier is very energy efficient. However, the yellowish color that it produces have a very poor "color rendering". Have you ever seen the color of your own skin under one of these lights at night? )

The number of lights connected to each outgoing circuit is quite standard for compound lighting. Most installations only connect 6 lights to a circuit regardless of the MCB rating or the rating of the light fixture which usually varies between 70 watt to 250 watt..

So you can actually know how many outgoing circuits you need once you know or estimate how many lights would be installed inside the building compound.

Now let us look at a few of the feeder pillar pictures

Picture 3 – Feeder pillar for compound lighting


This is for a compound lighting system at a public building. Notice the concrete plinth that it is sitting on.

Here there is also an additional power socket installed but it is located outside the cubicle. Therefore, it has to be of a weatherproof type.

Picture 4 – Outdoor power socket



When you install electrical equipment outside of a protected room, under the rain and hot sun, it need to be of a weatherproof type.

Electric voltage inside an electrical equipment and appliance is very dangerous. It can easily kill people.

Every knows that. But when it is installed at a location where there is a possibility of water seepage into the enclosure, then the equipment become extremely dangerous.

That is why when we say weatherproof, the design, manufacture and installation must comply to a certain criteria and quality standard.

The category of degree of waterproofing is graded by what is called IP rating.

Picture 5 – Weatherproof socket IP rating



The 13A power socket here is rated as IP 66. The letter IP stands for Ingress Protection. I think that was how it came to be.

The first number after IP is the grade of protection against ingress is dust and solid objects into the enclosure.

The second number shows the class of protection against harmful ingress of water. The number 6 in this case means that the outdoor socket unit has been designed and manufactured to withstand against water jets to the unit from any angle.

This is important because being installed at a landscape area there are possibilities of strong water jets when the caretaker is watering the landscape garden.

A cleaning work of the compound area after parties and functions may also expose the unit to water jets.

IP Rating of the feeder pillar metal enclosure

I have spoken of the need to waterproof the outdoor socket outlet. The feeder pillar metal cubicle is even more important to be waterproofed.

I did not take the photo shot at the manufacturer label of the feeder pillar. However, I think the IP rating of the above feeder pillar would not be less than IP 56.

This means that the protection against the ingress of water is of the same grade as the 13A socket.

However, the protection against the ingress of dust and solid objects is probably at grade 5, which is one step lower than that for the socket.

At grade 6, the enclosure would not permit any ingress of dust at all. But at 5, some very small dust particles may still be able to enter the feeder pillar enclosure without any harmful effect to the operation and quality of the components and installation inside the cubicle.

The photographs above was taken of an existing feeder pillar for a compound lighting. The other 2 more below are from a new installation that is still in progress.

Picture 6 – New feeder pillar installation in progress



You can see that the underground cables to and from this feeder pillar are not yet terminated.

This unit seem to be much bigger than then existing one shown above. However, that does not necessarily mean it carries more electrical load or anything.

It only means the cubicle design provides more space inside for the access to the components and parts. Usually a bigger unit cost more even if the schematic design used to manufacture them is the exactly the same one.

Picture 7 – Cable entry to the feeder pillar



For readers who are looking for some details on the construction of the feeder pillar, bellow is an example. These 4 diagrams provides you enough measurements to locate the unit precisely at a tight space in a building compound.

With the single line diagram in Diagram 1 above, you can even get a pretty accurate estimated cost from the manufacture and supplier if you allow them to use their standard parts and components.

Diagram 8 – Feeder pillar front view



Diagram 9 – Interior component layout



Diagram 10 – Side dimensions



Diagram 11 – A section showing how the components are to be arranged and routed


Copyright http://electricalinstallationwiringpicture.blogspot.com Feeder pillar single line diagram

Compound Lighting Installation Pictures

You will find below some pictures and diagrams on the installation of compound lighting. Only one type of lighting you will see today. I will upload other types some other day.

Picture 1 – Compound lighting installation



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The construction at the above site was still in progress when I took the above picture.

The woodwork that you see around the light pole in the picture was for the landscape work. The project was in the final phase of construction.

The external lighting and landscape works were progressing in full speed.

The underground cabling for the compound lighting has been installed. The electrical contractor was then progressing with the installation of the foundation for the light poles.

The light pole in Picture 1 was installed as a mock-up unit so I could check and comment. I took some pictures at the base of the pole for reference, which you can see below.

I however rejected the mock-up unit because the internal wiring and termination was not yet carried out.

When the wiring is done, I will take some pictures and send them up here for readers who need them.

Picture 2 – Light pole mounting base



Some readers may say that this is a strange way to locate a light pole, which is above the drain. A more normal method would be more or less like the one in Picture 7.

Here the design-and-build contractor had a problem of locating a few of the compound the light poles at the open carpark area because there are several drains running between carpark boxes.

These drains were supposed to be located at the boundary of the land being developed.

However, it turned out that with the presence of the drains the actual land space for the landscaping works (e.g. trees, shrubs, etc) was too narrow to grow larger trees.

Therefore, the client agreed that the drains be relocated through the middle of the carpark area.

Construction people tend think that electrical things are very flexible and easy to be moved around just like a wiring cable.

I never liked that notion. It is true in this case, however.

Now the compound light poles have clashed with the drain. At some places, the poles have been moved to between two carpark boxes.

However, there have been concerns that accidents may damage the light poles.

As a result some poles of the compound light were located right above the drains.

The main contractor asked me how to place the pole bases on top of the drain cover.

I told them that the only real solution I have ever seen in such situations was only by constructing a cast in concrete base together with the drain, with the construction drawings of the light pole’s concrete foundation designed and endorsed by the civil work’s design consultant.

Anything less would be an experiment and I would not accept anything less because the building under construction was a high profile building and an important landmark.

A failed method of installation of the compound light poles would be extremely embarrassing for the supervising engineer, which was me.

The building owner’s resident project manager was aware of the problem and this helped me get a reliable concrete foundation for the 8 meter steel poles of the compound lighting.

Picture 3 and 4 below shows the concrete base work is progress. Observe the reinforcement steel bars used.

The completed base is what you see in Picture 2 above.

Picture 3 – Construction of a light pole foundation on top of a drain



Picture 4 – Another view of the light pole base



Picture 5 below gives another view to show the mounting bolts and nut above and below the pole’s base plate.

Picture 5 – Another view of the pole’s base plate mounting



Picture 6 – Another pole base just completed



Picture 7 – A precast light pole foundation in position



Another cast in situ pole base. I show this picture just to show the readers the entry method of the multi-core underground cable.

You can see two lengths of cables because this pole would be in the middle of the loop circuit along that light row.

If you do not understand this, leave it. I will explain the circuit in detail in future posts. With some picture too.

That was the more difficult part of the compound lighting installation in this project.
This type of electrical installations is usually simple works. Not much difficult issues.

I have more pictures on the compound lighting that I wish to upload to this blog. I am however too tired already. It’s already 4 am.

I will upload the other pictures in future posts.
Chiao.


Copyright http://electricalinstallationwiringpicture.blogspot.com Compound Lighting Installation Pictures

Electric trunking installation pictures

As will be shown by the pictures below, no electrical installation work of a significant size can be done properly without the use of an electric trunking.

A trunking is a larger size of a conduit. When you need to run a number of electric conduits along each other for a significant distance, then consider using a trunking in place of the conduits. There are so many sizes you can choose from.

Picture 1 – Electric trunking running below soffit of floor concrete slab



=================  RELATED ARTICLES: Underfloor trunking below structural rebars |  Lighting flexible conduits |  Conduit to trunking connections |  Cable ladder pictures |  Electrical conduits and trunking pictures | Electrical panel under water pipes  | Electrical busduct installation pictures | Electric conduit 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 | Electrical installation pictures
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This is an example of a trunking installation above ceiling level, under the soffit of the concrete floor slab.

I also labeled some of the other services there for the benefit of those non-electrical readers who need pictures like this for reference, to know what is what among the myriads of pipes and wires running above the ceiling level.

Notice the label “E” and “N” on the electric trunking. “E” means Essential Supply and “N” Normal Supply.

All large buildings need labels of some sort to distinguish two types of electric supply: the “normal” electricity supply and “essential” electricity supply.

The normal supply means the supply that is obtained from the public electricity supply. When the public supply fails, then your have a black-out.

If you live at a higher floor of a flat building, then you have to walk down the emergency staircase to leave the building.

That is why an “essential” supply is provided. This is normally generated by one of more standby diesel generators.

When the public supply fails, the standby generator automatically kicks in and provides the electricity to the building through the cables run inside the “E” trunking.

If you wall socket is supplied from these cable, then you have electricity even during a black out.

Picture 2 below shows how the electric trunking is installed at location like this.

Picture 2 – Hanger rod



Two hanger rods and a length of angle iron are normally used to support the trunking at these types of location. The angle iron can be as long as is necessary to accommodate the number of trunking it will support.

The hanger rods would be as long as needed to position the height of the trunking to a level that would necessitate a minimum number of bends.

Bends are more expensive than the straight piece regardless of whether you buy it ready made from factory or fabricated at the site from a straight piece.

Custom made at site means labor costs, which can even result in a much higher cost in the end.

So far all the clients of the projects that I was involved in did not accept custom made trunking bends. Neither do I.

Custom made bends tend to have sharp edges that injures the insulation and protective outer sheath of electric cables.

Injured cables can cause many problems during the operation of the installation even though they normally seem to pass all tests and inspection during construction.

I always warn contractors not to use custom made trunking or cable tray bends. When they have to, they are required to notify me or my staff in advance and specific locations where they are used should be identified and permission granted for each one on case by case basis.

Picture 3 – Vertically mounted trunking



This picture shows electric trunking when they are mounted vertically.

This installation was inside a fan room at the roof of a multi storey building. A number of electrical panels would be located on that wall later. That is the reason for the multiple trunking installed.

This room was basically a machine room. It housed many of the smoke control and ventilation fans of the building.

As usual, wiring to machines and electrical equipment requires frequent maintenance due to overheated cables, addition of new machines, replacement or upgrading to bigger machines, etc.

All these reasons require frequent troubleshooting and rewiring of electric cables. The use of trunking makes the maintenance and upgrading work much easier. That is why trunking are used in these sorts of locations even though there would only be just a few small electric cables to be installed inside them.

The following pictures show how the trunking are fixed to the wall, the types of mounting brackets used, etc.

Picture 4 – Mounting bracket for wall mounted trunking



The above picture and the one below show two types of mounting brackets. These two are the low cost types.

Picture 5 – Another type of vertical mounting bracket



Same method, only different materials.

The type shown in Picture 6 would cost more, but it can provided higher strength which is needed for long vertical trunking such as those inside electrical risers in a multi storey buildings.

Picture 6 – Mounting bracket for long vertical trunking



This type also is suitable for large trunking sizes, which can carry more cables.

Picture 7 – Trunking 90 degree bend



This is an example of a bend. This one was factory-manufactured.

Picture 8 – A hanger rod support bracket installed by the air-conditioning contractor



This trunking and the hanger rod support were installed by the air-conditioning contractor. It is exactly the same as the method used in Picture 2.

However, I show this picture for a different reason.

Notice the white label “AC” painted under the trunking. This label is painted to all electric trunking installed by the air-conditioning contractor to distinguish them from electrical trunking installed by the electrical contractor.

It is a common practice that all electrical conduit and trunking are required to be painted orange color.

An air conditioning system runs throughout all floors of a modern high rise building. The locations of air-conditioning electrical equipment are not restricted to just inside the AHU rooms of a building floor.

There are numerous fan coil unit (FCU) throughout the floor area. Where individual control of the air temperature and quality inside a room is required, an FCU unit is needed.

So, an electric circuit need too be run there.

Many times, especially in large buildings, the works of electrical wiring to all these air-conditioning electrical equipment are located inside the air-conditioning works contract.

If for nothing else, this arrangement eliminates many coordination problems that usually occur when too much interfacing is required between different trade contractors.

The electrical contractor is then just required to run supply cable to the main electrical panel of the air-conditioning system at each floor. The electrical panel and all downstream cabling and wiring are parked under the air-conditioning contract.

Neat.

Okay. This is all I have time for today. We will meet again in the next post.

Readers new to this blog can find more pictures by visiting this post, Electrical installation pictures. There you will find links to other posts that contain pictures on the topics that you are looking for.

That is faster than searching in the ARCHIVE sidebar.



Copyright http://electricalinstallationwiringpicture.blogspot.com Electric trunking installation pictures

Electrical busduct installation pictures

The following pictures show electrical busduct risers in actual installation.

Picture 1 – Typical busduct rising main at individual building floors



================= RELATED ARTICLES: Underfloor trunking below structural rebars |  MATV trunking riser | Substation rooms layout diagram |  Conduit to trunking connections | Cable ladder pictures | Electrical conduits and trunking pictures | Electrical panel under water pipes   | 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 | Electrical installation pictures | Building’s electrical rooms layout

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The above picture shows a typical installation of busduct rising mains in the riser room at individual floor of a high rise building.

This picture was taken in the riser room at one of the upper floors of a high rise building.

From the picture you can see most of the major components of a busduct riser system.

(NOTE: for readers who are not from electrical disciplines, a “riser” is a feeding cable or pipe giving supply to upper floors of a multi-storey building.

In electrical works, a riser is a set of cables the supply the upper floors. The electrical distribution diagram in Diagram 3 may make you understand this better.

The feeding cables “rise” up straight to the top floor. Then at each floor a tap-off unit is connected so electricity can be supplied to that floor.

An alternative is to run one individual set of cables to each floor. Then there would be many cables that need to be installed the number of which is directly proportional to the number of upper floors.

One single set of bigger cables is always cheaper to install and much easier to handle.)

Observe that there are three tap off units there: two units of 60A three phase, and one unit of 100A three phase. The one at the highest position of the three is the 100A tap off.

Why three units?

There are actually three risers here: one for the “normal” main electricity supply. This supply is just the normal authority supply like the one you have in your house. The 100A tap off unit is for this riser.

The second tap off, which is one of the 60A units, is what is called “essential supply”, or “emergency supply”. It is a normal authority supply like the one you have from the 100A tap off unit above.

However, it is also backed by a standby diesel generator. This means that if the electricity supply from the authority distribution network fails due to problem with their underground distribution cables or whatever, the standby electric generator would kick in and switch in the locally generated electricity to this electrical riser.

Large capacity electric generators are expensive, however.

Therefore, it is not economical to supply all electricity needs in the building from this generator. That is why separate electrical risers are used, and the “normal” riser is not backed by the generator supply.

The third tap off unit (the second 60A unit) is for the air conditioning system.

It is quite common (and is considered a better design) to have a separate feeder cable for the air conditioning and mechanical ventilation (ACMV) system in a large building. That is the reason for the third electrical riser here.

One more point to note here is that some office buildings use the generator-backed supply (i.e. ESSENTIAL supply) to feed the electrical riser for the air-conditioning system.

With this arrangement, ACMV equipment that need to continue operating even during the mains failure do not need to be connected to “ESSENTIAL” supply riser, which is why it is given a separate riser in the first place.

Observe the large flexible conduits coming out from the bottom of the tap off units and connect to the orange-colored electrical trunking. Some installations use rigid metal trunking for this purpose.

Cables are run from a tap off unit into the flexible conduit to go to the orange metal trunking.

They run inside the trunking to connect to the respective sub-switchboard.

You can see only two sub-switchboards here. These are for the “NORMAL” supply and the “ESSENTIAL” supply.

The switchboard for the air conditioning system is normally located inside the AHU room of that particular floor.

From the sub-switchboards, separate outgoing cables are run inside the trunking to connect to separate distribution boards (DB) on that particular floor.

That is all that I wish to elaborate on Picture 1 above.

My intention is so that beginners in electrical installations can understand the major components that make up a busduct riser system.

Now let us look at a few electrical diagrams. The diagrams can give a more complete overall view of a simple electrical system in which a similar busduct riser forms a part.

While the busduct risers in Picture 1 are for a high rise office building, the following diagrams are for much simpler installations. They are for the nurses hostels at a hospital complex.

Even though electrical installations at hospitals are relatively much more complex than the office building above, the installation at their hostel and staff quarters buildings are usually very simple.

That is why I choose to use them here. My objective here is to give casual readers and beginners in electrical works an overview and general understanding of the basic functions and installation of a busduct riser system.

The actual electrical diagram used to construct the installation in Picture 1 might be too complicated for this category of readers. I do not wish to scare them away.

Diagram 2 – Part single line diagram for a multi-storey nurses hostel



This diagram is part of a larger diagram which is in Diagram 3.

Diagram 3 – The full layout of the single-line of Diagram 2



As you can see, you cannot read much of the labels and notes in Diagram 3.

I produced this JPEG graphic from an AutoCAD drawing files (i.e. DWG file format) which is probably the most widely used drawing programs in the construction industry.

I used the program’s BMPOUT command to produce a BMP file format form the DWG file format. Then I converted the BMP format into the JPEG file format using the Microsoft Paint program.

However, this method does not seem to be effective enough for AutoCAD drawings that have been produced for A1 or A0 printing as the original sizes.

If anybody here knows a better method, please let me know.

Okay. Let’s get back to the electrical single-line diagrams.

In Diagram 1, you can see that the hostel building is six-storey, which Ground Floor, then Level 1 to Level 5.

Usually for a building of this height, designers do not use busducts. However, they do in this case. Maybe that was because the project already used so many busducts at the main hospital complex and other (much higher) staff quarters buildings, it made sense to also use busducts here.

In any case, the components of the busduct system that you see in Picture 1 were used at each floor of Level 1 to Level 5.

However, at Level 1 you have one or two more components. Picture 4 below shows a view of the electrical riser room at Level 1 (the first higher level). It is the same building as that in Picture 1.

Picture 4 – A view of the electrical riser room at Level 1 (the first level above ground level



As you can see, there are definitely more components here that in Picture 1.

However, actually there are basically only two new components at each riser, which is the TERMINATION BOX (some people call it “FEED IN BOX”), and the incoming cables that terminate into the termination box.

Apparently there is an extra tap off unit here, but it is the same component type.

Observe the cables coming into the termination boxes.

The biggest termination box has cables with black insulation terminated to it, while the other two termination box has red cables.

The red cables are red-colored because they are fire rated cables. Remember the “NORMAL” and “ESSENTIAL” supplies that I explained above.

Why the generator-backed “ESSENTIAL” supply cables need to have red colored insulation?

It is because this supply is part of the fire emergency system of the building. Which means this part of the electrical installation system must also comply with the Fire Requirements of the Building Bylaws and the Fire Department.

A fire-rated cable must be able to continue operating for a certain number of hours during fire before it fails. This is the requirement. It used to be MICC (mineral insulated copper cables) cables that play this role, but now people use mostly the “fire-rated cables” for this purpose except in very special installation condition.

The fire-rated cables are cheaper, easy to install and maintain.

(See more pictures of fire-rated FR cables at this post, FR electric cable installation pictures.)

The black-colored cables are from the “NORMAL” supply. That means the other ends of the cables are connected to the “NORMAL SUPPLY” main switchboard.

While the red cables are connected to the “ESSENTIAL SUPPLY” main switchboard.

Which means the “ESSENTIAL SUPPLY” main switchboard is the one that is backed by the standby electric generator.

Is it too complicated? I hope not.

Even if it is, have no worry. I will spend a post or two on the overall system of electrical installation for large multi-storey buildings soon. Now I am actually building up section by section.

I will end this post by attaching a single-line diagram for a building similar to that of Diagram 4. However, this one used the normal cable riser instead of busduct riser. I hope the all readers of this post can locate the difference in the two diagrams.

There are also a few more pictures for the risers of Picture 1 and Picture 4. These pictures provide more information and better views for a few of the busduct components.

Diagram 5 – A distribution system using a cable riser instead of the busduct riser



Picture 6 – Another view of the busduct risers at riser room



Picture 7 – The front view of one of the 60A TPN tap off units



Picture 8 – A closer view of the vertical busduct showing the arrangement of the conductors inside



Notice that there are five conductors inside the busducts: the three phases, the NEUTRAL conductor and the EARTH conductor. The arrangements of the conductors are as shown on the busduct casing.

Picture 9 – A view of the cable entry into the feed in box and the connection of the equi-potential earth conductor



Observe that the copper tape was connected to a wrong place.

The metal plate where the cables are connected to is a removable plate. The copper earth tape should stay clear of this removable plate.

The tape should be connected to the main body of the termination box at a location where it is least likely to be disturbed.

This installation work was actually still in progress when I took these pictures. The copper tape connection was later rectified.

You can see more pictures at this post, Electrical installation pictures.
Copyright http://electricalinstallationwiringpicture.blogspot.com Electrical busduct installation pictures