Basic Things to Know About CCTV as a Technician

Some Basic Things to Know About CCTV as a Technician, If you are manager just share this with your team.

Cable Running

Many facilities use closed circuit television (CCTV) as part of an overall security system. Cameras mounted on buildings or ceilings transmit signals to a central monitoring room. CCTV takes two forms ---hard-wired or wireless. A technician just starting out in CCTV has to gain a knowledge base of how CCTV works, so he will be able to install, test and troubleshoot systems. Do not run 3+1/4+1 CCTV Cable, use RG11, RG6, RG59 only. Find-out the length of Video Cable from DVR to Camera, it should be on limit. Do not overlapping with High voltage wire. Do not join the Video Cable, use complete length ( One drum Video Cable its 305Mtr) of wire. If cable layed in out door use Armour cable.

RG 59 which can transmit signals up to 200 metres. This distances are for a single run of cable with no amplifiers or in-line correctors.

RG 11 which can transmit signals up to 270 metres. It is more expensive because it is thicker. This distance are for a single run of cable with no amplifiers or in-line correctors.

RG 6 which can transmit signals up to 400 metres. It is more expensive because it is thicker. This distances are for a single run of cable with no amplifiers or in-line correctors.

Twisted pair cable is a good alternative to coaxial cable if the length of the run is more than a few hundred metres. With pure cooper twisted pair, runs of up to 600 metres can be used without any in-line repeaters.

Troubleshooting Signal Loss

The picture on the monitor should never be fuzzy or have interference patterns. If it does, signal loss is occurring somewhere in the system. Technicians have specialized testing equipment and know how to use them in order to troubleshoot systems. Usually, a technician starts at the camera and works her way back to the receiver. She/he checks each connection until the test equipment indicates a loss. Some common problems are corrosion due to moisture inside the connectors or cables chewed through by animals.

Camera Installation

CCTV technicians can't be afraid of heights. Cameras are mounted high on the sides of buildings, or high in the ceiling areas of stores. You have to use a boom lift to reach spots to mount cameras. If you suffer from heights, becoming a CCTV Technician may not be a valid career path.

Cables are installed from the camera to the receiver station. You will have to drill through masonry block and below floor to run the cable. Be prepared to navigate through tight cramped quarters to get the cable from the camera to the receiver. Bring along a change of clothes, since you will get dirty in the process.

CCTV Camera Installation Tips:-

1. Test all equipment before installation. Therefore equipment can be replaced before arrival on-site if needed.
2. Ensure the mounting brackets of outdoor speed domes are properly sealed to prevent condensation in the camera housing.
3. Ensure sufficient space for camera, lens and connectors when choosing camera housing.
4. Avoid direct sunlight on equipment as it raises the temperature of the equipment.
5. Position cameras out of reach of vandals or 'curious' people.
6. Mount good quality mounting brackets in a stable location to avoid unstable or vibrating images caused by vibration or wind.
7. CS Mount cameras placed inside, at industrial or dusty/damp installations should be placed into outdoor camera housings.
8. Avoid installing cameras too high above the subject thus preventing 'top-of-head' video images
9. Ensure camera mounting poles are mechanically secure to avoid vibration on camera images
10. Before connecting power, ensure the supply is 12VDC regulated.

CCTV Cabling Tips:

1. Avoid running video cable parallel to AC power cables, especially those carrying high current.

2. RG59U Coax runs should not exceed 180m for colour and 280m for B/W

3.Avoid sharp bends when cabling

4. Avoid cable joins and using BNC barrels

5. Avoid over-tightening cable-ties

6. Ensure use of proper co-ax wire-stripping and crimping tools

7. Ensure BNC Connectors are properly crimped

8. Use Rubber BNC Boots after crimping to protect crimped area and bend radius

9. Mark or label camera and data signal cables

10. Outdoor cable runs should be housed in UV-proof conduit

11. In lightning prone areas, install surge protection devices

Final Testing and Teaching

A technician tests the system after it's installed. This involves knowing how to aim the cameras, knowing how to operate the monitoring equipment in the security room and knowing how to instruct the final operators of the system. You have to be part teacher. You may have to deal with people who have no knowledge of how a CCTV system is operated, so you have to use layperson-friendly language during the training process.

As you are a Engineer / Technician remember this few points:
Visually inspect all major components and connections for signs of deterioration or damage

Check all control equipment (DVRs, VCRs, monitors, multiplexers, video switchers, telemetry units etc) for correct operation

Check mains & power supplies and stand-by batteries including charging rates.

Check environmental conditions for adverse effects, including growth or shrubbery obscuring camera views

Check time and date settings in equipment and update the settings as appropriate

Check integrity of all cabling and sample check external insulation for damage

Clean cable fixings for security

Check auxiliary lighting equipment, infra-red units and photocells (if any) for correct operation

Check air vents are clear in all control equipment including PCs

Clean cameras, lenses and housing surfaces as necessary

Check al glands and seals on external equipment

Clean control equipment surfaces including PC (if applicable)

Establish regular back-ups are taken

Check camera is aligned to user specification, pictures for correct field of view and adjust as necessary

Check brackets, towers and fixings for corrosion or damage. Check clamping bolts/brackets are tightened correctly

Check wash/wipe units and wiper blades (if any) for correct operation and fill washer reservoir where necessary

Check quality of recording during day time and night time modes

Check pan and tilt assembly (if any) including fixings, electrical connections and functions.

Check the satisfactory CCTV transmission of images to remote site (if applicable)

Check warning signs are in place

Check all camera presets

Check all alarm presets

Video Servers Bridge The Gap

Network IP solutions are touted as the answer for security problems, but analog cameras dominate most existing camera configurations. Video servers span the distance between analog and digital systems, upgrading existing systems and holding tantalizing potential for newer uses.

One benefit of digital systems is faster response time, with video servers bridging the gap between legacy analog systems and digital IP systems. The universal function of a video server is to transform analog signals into digital signalsimportant in places with existing analog frameworks. 

Video servers, sometimes known as video encoders, bridge the gap between analog CCTV surveillance systems and digital IP based systems. Video servers are a great budget conscious, transitional product for those who are looking to gain some of the features and benefits of network based solutions but, aren’t ready to make the full jump.

If you’ve installed analog cameras in the past few years they’re going to be functional for quite some time.  There’s no need to shortchange that investment.  Video servers will allow you to maintain those analog CCTV cameras while enhancing your video surveillance system to provide the benefits of IP video.

Why Use A Video Server?

So you don’t have to discard your existing analog cameras! A video server allows your functioning analog CCTV video surveillance system to be integrated with a network video system. Gain the benefits of network video without having to replace what’s bought, paid for, and still working.

Coax Cable Is Expensive

Installing coaxial cable is expensive and once installed, hard to justify re-cabling with Cat 5. And with the average lifespan of an analog camera at 5 - 7 years, what fails first are the VCR’s and DVR’s used to record the video. Video servers not only allow you to keep existing analog equipment such as analog CCTV cameras and coaxial cabling but open up a true network video system because the video is consistently sent over an IP network.

A video server connects to an analog video camera via a coaxial cable and converts analog video signals into digital video streams that are then sent over a wired or wireless IP-based network (i.g., LAN, WLAN or Internet).

Video Server Advantages

• Use of standard network and PC server hardware for video recording and management instead of DVR’s or VCR’s
• Scalability in steps of one camera at a time
• Possibility to record off site
• Ability to remotely access and control analog cameras over an IP network
• Future-proof because the system is expanded easily by incorporating IP Cameras

Video Server Components

• Analog Video Input: For connecting analog camera using coaxial cable.
• Processor: For running encoder’s operating system, networking & security functions, encoding analog video using various compression formats, and video analysis. The processor determines the performance of a video encoder measured in frames per second (FPS).
• Memory: For storing firmware (computer program) using Flash, and for buffering of video sequences (using RAM).
• Ethernet/Power over Ethernet Port: To connect to IP network for sending and receiving data, and for powering the unit and the attached camera if Power over Ethernet (PoE) is supported.
• Input/Output (I/O) Connectors: For connecting external devices such as sensors, relays, and lights.
• Audio In: For connecting a microphone or line-in equipment and audio out for connecting to speakers.

What To Consider When Choosing A Video Server

• The number of supported analog channels
• Image quality
• Compression formats
• Resolution
• Frame rate & features such as pan/tilt/zoom support
• Audio
• Event management
• Intelligent video
• Power over Ethernet (PoE)
• Security Functionally

IP Convergence

Video servers are a great problem solver when you’re faced with the challenge of migrating a large investment in analog CCTV cameras to IP video.  Next up I’ll go into more detail about a very important benefit that video servers provide - Event management and intelligent video capabilities with the ability to use advanced video monitoring software

When Lightning Strikes Alarm Systems

April showers bring May flowers, or so goes the old cliché. Warmer weather also brings with it thunderstorms and power surges galore. All too often the result is false alarms, lost data and the destruction of high-tech electronic equipment.

Although lightning is a major concern during good weather, it doesn't have to be warm out for electric motors, smelting operations, heavy industry and other electrical concerns to spell big trouble for the equipment for which fire and burglar alarm technicians are responsible.

Lightning is a common concern for alarm technicians because of the suddenness with which it can strike. The damage that it can cause may involve a lone device connected to an internal low-voltage cable, like an addressable manual fire pull or an individual circuit board. Or it might involve an entire motherboard within a fire or burglar alarm panel.

Sometimes the damage is light while other times it can be catastrophic, tearing through the system from one end to the other. Having a fair understanding of how lightning works and by using good installation practices, along with quality equipment, technicians can limit the amount of damage that does occur.

Mechanics of a Lightning Strike

Any device that connects to a metallic wire can suffer damage at the hand of lightning. This is true whether the strike is direct to the cable itself or indirect by virtue of inductance. Sometimes no matter what you do, lightning will do irreparable harm.

Concerning a direct hit to equipment, lightning can enter through multiple paths from outside the structure. A good example is a campus environment where there are many buildings.

Lightning also can enter the structure through the public electric bus via outside power lines or one of the many paid subscription services now available. Examples include conventional telephone, cable television networks and satellite dish systems.

In a burglar or fire alarm system, once lightning enters the equipment through one of the methods cited above it can migrate to a signaling line circuit (SLC), initiating device circuit (IDC), notification appliance circuit (NAC) or some other low-voltage line. Another example is the coaxial cable or twisted pair unshielded wire that carries video images in a CCTV system.

"The focus is usually on SLC loops [burglar and fire alarms], low-voltage data [networks] and coax cable [CCTV].

Manufacturers are well aware of the problem lightning poses and for this reason they commonly build a limited amount of surge protection into their electronic systems at the point of manufacture. In most cases this is done right on the motherboard itself.

This ploy most often includes add-on printed circuit (PC) boards and any number of subsystems, such as smoke detectors, glass breakage sensors and others. And yet damage or total destruction can and often does occur when lightning appears on the scene.

One fire alarm manufacturer uses optical isolation on the data loops to minimize lightning damage. Damage in this case often occurs when lightning induces a high voltage current in the internal wiring of a building. This can be especially problematic in campus environments where data lines travel under ground between buildings.

This design incorporates the idea of isolating the grounding differential from the other buildings. Nice little spark gaps and it does help, but the problem is, when incorporating second-rate surge suppression, you get a feedback loop up the case ground into the smart chip.

When you consider the multiple pathways over which lightning can travel, you must also think about distance with regard to proximity as it pertains to the surge protection device that acts to clamp the surge voltage and route the strike current to earth ground.

This is true whether it involves external surge protection or those internal to the device itself. Many years ago an engineer told this writer that lightning will often travel well beyond the point where the surge voltage is clamped. All too often this ends up damaging critical circuits, not to mention the possibility of arcing within the panel itself.

The most panels can handle some of this current, but not all of it. This is especially true where there's a significant voltage differential between equipment grounds of all the interconnected equipment.

Think Ahead When Installing

As mentioned earlier, one common application where lightning can cause considerable damage involves integrated systems across multiple buildings. Because of the matrix of wires that travel to and from each building, being installed either overhead or underground, the propensity for damage is considerable.

In this case a single head-end system may be employed to provide a number of low-voltage services, such as fire, security and/or CCTV protection. Here, especially proper precautions must be taken, such as the use of quality surge protection.

One case in point is a motel with multiple buildings serviced in the summer of 2008, by Nick Markowitz, owner of Markowitz Electric Protection of Verona, Pa. According to Markowitz, the location experienced a lightning strike that damaged a fire alarm system, three cameras and a washing machine. The lightning affected systems in three separate buildings by first entering a restaurant and then traveling throughout the entire campus.

"The camera system is one of those cheap cameras-in-a-box deals that uses four-wire telephone cable. One of the cameras is located in the restaurant and is fine, but another one took a hit and the wiring was damaged," says Markowitz. "The other two cameras were converted from phone wire to inline powered coax and lightning took out the converters and power injectors."

Lightning entered through one of the cables that crossed between the buildings, Markowitz reports. A close examination revealed that there wasn't any surge protection on any of the low-voltage cables that serves video or any other centralized system. And yet damage was spotty, which Markowitz found puzzling considering the severity of the hit.

"I find it strange that the monitor and one of the other cameras were fine but all the rest was trashed. Usually when lighting strikes like this, everything goes at once," he adds.

Equipment Circuit Design Changes

Manufacturers have changed the way they construct and package components contained in their low-voltage systems. Included is the way those components are installed on PC boards. Both of these factors have altered the way alarm technicians protect their electronic systems from lightning, says Pecore.

"In 1997, Stormin Protection Products officially became an engineered lead business because the projected sales in the area of low-voltage surge suppression for fire alarm, CCTV and access control systems will be in greater demand as the progress of SMT [surface-mount technology] literally took over the industry," says Pecore.

SMT technology allows manufacturers to reduce power consumption as well as extend the length of time batteries will provide backup power. If nothing else SMT components have allowed manufacturers to reduce battery size to meet a specific code requirement, such as standby time. SMT technology poses a problem because it represents a relatively low impedance to lightning.

“SMT technology for an old guy is a dirty word. It spells out one thing, nothing but trouble,” says Pecore. “Manufacturers took all the linear and high capacitance devices off the board and left me with a featherweight that if I hiccup just right, it will blow.”

Design engineers have eliminated linear power supplies, replacing them with Wheatstone bridges. Also, low-impedance capacitors and resistors have replaced heavy-duty capacitors and resistors, and smart chips have replaced entire printed circuit boards. 

“Low Pico Farad devices have also replaced other components — all for the sake of reducing current draw,” says Pecore. “As a result of these changes, fire alarm panels (and other electronic systems) have become more susceptible to surges, impulses and ground strikes.”

The idea is to raise the impedance of the panel, not lower it, and to do this the installer has to look for ways to create an alternate path that looks more inviting to high-voltage lightning than the panel’s motherboard.

According to Pecore, the answer is an inline series hybrid three-stage, two-tank circuit that works to impede strike current while shunting it to ground. This is accomplished by focusing on the characteristic frequency associated with lightning.

Thanks to SSI Magazine FOR HELP & Thanks to John Pecore, President at Stormin Protection Products Inc