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

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RELATED ARTICLES:  Electrical Services Color Codes

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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.

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1 comment:

-JoJo- said...

great for sharing ur experience, that's what i need to know