Academic Business Consultants DHTI+ Chapter 12 Security Systems David Stilson

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1 2008 Academic Business Consultants DHTI+ Chapter 12 Security Systems David Stilson Academic Business Consultants Chapter 12, Security Systems Page 1

2 Chapter 12 Security Systems 12.0 Introduction to Home Security Systems 12.1 Environmental Detectors and Alarms Alarm Sounders Smoke Detectors Temperature Detectors Carbon Monoxide Detectors Radon Gas Detectors Water Detectors 12.2 Security System Components Security Zones Security Panels Central Monitoring Alarm Signal Formats Backup Systems Door Strikes Intrusion Sensors Photoelectric Sensors Wired Smoke Detectors 12.3 Security Cameras Camera Types Camera Specifications Locating Cameras Camera Viewing Recording Intrusions 12.4 Security System Infrastructure Wired Security Infrastructure Wireless Security Infrastructure 12.5 Troubleshooting Security Systems Academic Business Consultants Chapter 12, Security Systems Page 2

3 Chapter Objectives Identify terms and technologies associated with home security systems. Describe security system sensor functions and specifications. Describe security camera features, specifications, and installation considerations. Identify common security system industry standards and building codes. Describe essential wired and wireless security infrastructure components. Terms and Technologies to Know Alarm Sounder Biometric Reader Bullet Camera Camera Iris Charge Coupled Device (CCD) Carbon Monoxide Detector Card Reader Central Monitoring Complementary Metal Oxide Semiconductor (CMOS) Dome Camera Door Strike Driveway Alarm Dual-Tone Multi-Frequency (DTMF) EOL Resistor Frequency-Shift Keying (FSK) Focal Length Glass-Break Sensor Ionization Smoke Detector Infrared (IR) Illumination Lux Rating Magnetic Switch Notch Filter Pan, Tilt, and Zoom (PTZ) Passive Infrared Motion Detector (PIR) Personal Panic Button Photoelectric Smoke Detector Photoelectric Sensor Polarity Reversing Relay Pressure Pads Proximity Reader Radon Gas Detector Security Zone Security Panel Temperature Detector Uninterruptable Power Supply (UPS) Video Monitor Water Detector Academic Business Consultants Chapter 12, Security Systems Page 3

4 12.0 Introduction to Security Systems The need for automated security systems continues to grow. Many home automation contractors specialize in security systems and do not bid on other jobs. Some installers spend their career becoming security system experts and find their knowledge and skills are always in demand. In this chapter we will cover the basic security system components that all installers should know. We will discuss environmental detectors, security components, and the infrastructure needed to create a robust security system. If you decide to become a security expert this chapter will help you start on the path. However, you should be aware that you could spend your entire career studying security systems and not know everything. (See figure 12.0) (Figure 12.0, Introduction to Security Systems) Academic Business Consultants Chapter 12, Security Systems Page 4

5 12.1 Environmental Detectors and Alarms You need to protect the home s occupants from toxic gases and fires before you do anything else. Fire causes many avoidable deaths each year. Virtually every local fire code now requires that fire detectors be installed in all new homes. Most fire departments consider fire detectors to be so important that they give them away to people who cannot afford them. In addition to fire detectors, we will cover methods to prevent injury and death from an overexposure to carbon monoxide and radon gas. We will also discuss methods of protecting homes from water damage. In this section all of the environmental detectors are stand-alone devices. In later sections, we will show how environmental detectors can be integrated into a home security system. (Figure 12.1, Installing Fire Detectors) Academic Business Consultants Chapter 12, Security Systems Page 5

6 Alarm Sounders Many environmental sensors are designed to detect life-threatening conditions. When fire, smoke, and carbon monoxide detectors are triggered, they need to immediately inform the home s occupants of the condition. Alarm sounders produce a loud audible sound that can be heard in every room in a home. Studies show that an alarm with a sound pressure level (SPL) of 65 db can alert most people when they are awake. An SPL of 75 db was chosen as an industry standard to alert people during the day, and to awaken them at night. The 75 db alarm sound measurement is made in the farthest room from the alarm, and at the height of a pillow on a bed. In addition to sound alarms, some systems include flashing strobe lights. Alarms with flashing strobe lights must be installed in any home where one or more people are hearing impaired (See figure ). (Figure , Smoke alarm with strobe light) Academic Business Consultants Chapter 12, Security Systems Page 6

7 Smoke Detectors There are two types of smoke visible and invisible. Grease fires and leaky furnaces can produce invisible smoke. Thick visible smoke comes from sources such as fireplaces and burning mattresses. Smoke detectors have either an optical (photoelectric) or physical (ionization) sensor. Photoelectric smoke detectors are best at detecting visible smoke. Ionization smoke detectors are best at detecting invisible smoke. Photoelectric smoke detectors contain an LED and a sensor that are angled 90- degrees from each other. In a photoelectric detector, the light from the LED does not make contact with the sensor under normal conditions. However, when smoke enters the detector, the light is scattered and some of it hits a photocell sensor. When light hits the photocell it triggers an alarm (See figure 12.12a). Ionization smoke detectors have a chamber that contains a harmless amount of radioactive material. The radioactive material produces a small electrical current. A change in the electrical current indicates that smoke has entered the chamber, and this triggers the alarm (See figure 12.12b). Some smoke detectors use both types of sensors to increase their sensitivity. (Figure a, Flash Animation: the student presses a visible smoke button and light is deflected to the photocell. A short alarm sound is produced.) (Figure b, Flash Animation: the student presses an invisible smoke button and radioactive material is passed through the chamber. A short alarm sound is produced.) Academic Business Consultants Chapter 12, Security Systems Page 7

8 Most smoke alarms are powered with a 9-volt battery that should be changed every six months (See figure c). Most smoke alarms will automatically produce a low-level chirp sound when the battery is low. All smoke alarms have a test button. When the button is depressed, the smoke detector will sound a low-level warning signal. If you do not hear a sound when the test button is pushed, change the battery immediately. Smoke detectors may operate as a stand-alone device. However, in most new home automation systems, the smoke detectors are integrated into the home s security system. (Figure c, Smoke Detector Battery) Academic Business Consultants Chapter 12, Security Systems Page 8

9 Temperature Detectors Temperature detectors can be used to test for conditions that are either too hot or too cold. Temperatures that are outside of a preset range will trigger an alarm. Hightemperature detectors are typically used for fire detection and are sometimes called heat detectors (See figure ). High-temperature detectors react to heat, not smoke. High-temperature sensors are usually mounted on a ceiling and trigger an alarm at approximately 135 degrees Fahrenheit (F). Some high-temperature sensors are able to sense how fast the temperature is rising. This type of temperature device is called a rate-of-rise sensor. A rate-of-rise sensor detects a rapid rise in temperature and triggers an alarm before a room reaches 135 F. Typically a rate-of-rise sensor looks for conditions where the temperature is rising more than 15 F in a minute. A fire may be in its initial stage when this condition is met. Low-temperature detectors are primarily used to protect equipment from freezing conditions that occur below 32 F. Low-temperature sensors can be used to protect water pipes from freezing, and to activate de-icing heaters in walkways. (Figure, , Temperature / heat detector) Academic Business Consultants Chapter 12, Security Systems Page 9

10 Carbon Monoxide Detectors Carbon monoxide (CO) is a dangerous gas that humans cannot sense without a detector. Carbon monoxide gas is colorless, tasteless, and odorless, and does not cause skin or eye irritation. At low levels carbon monoxide gas can cause fatigue. At higher levels carbon monoxide can cause impaired vision, headaches, dizziness, confusion, and flu-like symptoms. At very high levels carbon monoxide is fatal. Many people who state my house is making me sick may be inhaling carbon monoxide gas without knowing it. Carbon monoxide gas is produced by the incomplete burning of gasoline, natural gas, propane, kerosene, and coal. Unvented kerosene space heaters, leaking chimneys, and furnaces are sources of carbon monoxide in a home. Gas dryers with blocked exhaust ducts can also create high levels of carbon monoxide. Homes with an attached garage may experience high levels of carbon monoxide from automobile exhaust, gas generators, and unvented water heaters. Carbon monoxide is a larger problem in cold climates where the home may be sealed from outside air. In addition to homes, carbon monoxide detectors are available for boats and motor homes, where gas motors and small spaces can create dangerous CO conditions. The effects of carbon monoxide depend on the amount in the air, the length of time a person breathes it, and the health of the person. A low level of carbon monoxide will trigger an alarm in a CO detector long before people show symptoms. For this reason some people ignore carbon monoxide alarms. However, carbon monoxide detectors are based on the United Laboratories (UL) standard 2034, and do not produce false-positive results. Ignoring a carbon monoxide detector alarm can be a fatal mistake. All carbon monoxide detectors include a test button (See figure ). Carbon monoxide detector batteries should be changed at the same time that smoke detector batteries are changed. (Figure , Carbon Monoxide Detector/Alarm) Academic Business Consultants Chapter 12, Security Systems Page 10

11 Radon Gas Detectors Radon is a radioactive gas that comes from the natural breakdown of uranium in the soil and rocks underneath a home. Radon gas is colorless, odorless, and tasteless, and cannot be detected without a sensitive detector. Radon gas enters a home through cracks and holes in a home s foundation. Radon gas can also enter a home through well water (See figure a). Radon gas detectors are designed to be placed in the lowest living area of a home; usually in the basement. The detector displays the amount of radon gas in picocuries per liter of air (pci/l). A Curie (Ci) is the measurement unit of radioactivity. A picocurie (p) is one trillionth of a curie. A radon detector will trigger an alert any time the radon gas level rises above 4 pci/l. The amount of radon gas in a home is read on the detector s LED display (See figure b). Radon gas detectors are usually installed as a stand-alone device in a home. (Figure a, Radon Gas Sources) (Figure b, Radon Gas Detector) Academic Business Consultants Chapter 12, Security Systems Page 11

12 Water Detectors Insurance companies pay more claims for water damage than claims for fires, wind storms, or theft. Water damage from flooding rivers and storms is hard to prevent. However, there are water related events where damage is preventable. Some of the most common water related damage reports include the following events: In cold climates, water pipes freeze and burst A bathtub overflows A backyard pool overflows and floods a basement A washing machine overflows, flooding all the rooms near it A water heater breaks its seal and leaks A washing machine goes out of balance and breaks the attached water connections A water detector is a simple device that can be used to prevent water damage. There are two kinds of water detectors, float-switch and liquid-sensor. Float-switch and liquid-sensor water detectors can sound an alarm, turn off a water faucet, or both. A float-switch water detector is a mechanical device that floats in the water. Floatswitch detectors are activated when the water level reaches a preset level (See figure a). A liquid-sensor water detector is placed on a floor and is activated when it detects water. Inside a liquid-sensor is a small capacitor, an electronic device that stores a small electrical charge. When the liquid-sensor comes into contact with water, the capacitor is bypassed and electrical current flows. The electrical current activates the device, which turns off the water. (See figure b). After the water is removed, the liquid sensor will need to be dried to work again. (Figure a, Float-Switch Water Detector) Academic Business Consultants Chapter 12, Security Systems Page 12

13 (Figure b, Liquid Sensor Detector) Academic Business Consultants Chapter 12, Security Systems Page 13

14 12.2 Security System Components To design and install security systems, you should know a little about the people that break into homes. There are three general classifications of burglars: the amateur, the semi-professional, and the professional. The amateur looks for easy targets and will avoid your home if the risk is too high. The semi-professional burglar may check out your neighborhood for up to a week or more. However, like the amateur, the semi-professional will avoid your home if it looks like a hard target. The professional burglar only looks for extremely valuable items. The best way to stop professional burglars is to keep your valuables out of sight. This section focuses on electronic security measures and system components. However, all security experts know that the best electronic system should be supported with simple passive security measures. Always advise clients to take the following passive security measures before installing an automated security system: Install deadbolt locks on all exterior doors. Have the bushes and trees near the home trimmed, and keep them away from windows and doors. Make sure that your mail and newspapers are stopped while you are away on vacation. Ask a neighbor to stop by and turn on different lights, or get a house-sitter when you are on vacation. Never let your house go completely dark, even for short-term absences. Let your neighbors know when you usually come home from work so they can look for anything out of the ordinary. Lock windows and close curtains in any room where you may have a large screen TV and electronics, when you are not home. Mark a unique identification number on your valuables. Burglars avoid items that can tie them to your home, and they know that marked items are harder to sell (See figure 12.2). (Figure 12.2, Mark Valuables) Academic Business Consultants Chapter 12, Security Systems Page 14

15 Security Zones A security zone can be one room, an entire section of a home, all areas outside the home, or specific areas in the home and yard. A security zone can also be a single sensor. Security panels are designed to bring in data from different zones in the home. Usually one wire is used to tie several devices together in one zone. Each zone is terminated to one point in the security panel. When a security event is triggered, information from the zone is sent to the control panel. For example, if glass is broken on a rear door, the security panel can communicate that information to a local police department. Security zones are broken into two basic groups: wired and wireless. The number of zones a home can have is only limited by the security panel. It is common for a security panel to support zones. (Figure , Security Zones) Academic Business Consultants Chapter 12, Security Systems Page 15

16 Security Panels A security panel acts as a hub for all of the home s security components (See figure a). We have covered stand-alone sensors that can trigger an alarm in the event of an emergency. Fire, gas, break-in, and temperature sensors can be tied together in a security panel. The system can be configured to trigger alarms and to call for emergency services (See figure b). The advantages of using a security panel as a hub include: Centralized programming of security settings Remote monitoring of security events Automated alarms and lights Automated emergency calls Built-in backup systems (Figure a, Security Panel) (Figure b, Security Panel with Remote Monitoring) Academic Business Consultants Chapter 12, Security Systems Page 16

17 Central Monitoring With a security panel, all of the homes sensors are tied to a central location. When a security event occurs, alarms in the home are triggered. In addition to alarms, the control panel can communicate with remote central monitor stations. Security panels are designed connect to central monitoring stations by dialing a phone number, and sending codes that describe the problem. Depending on the event, personnel at the monitoring station may call either the home or emergency services. (Figure , Central Monitoring Station) Communicating emergencies over telephone lines can be unreliable at times. Phone lines can be busy or off the hook. The best way to prevent this problem is for the security panel to seize the telephone line. The security panel will interrupt all telephone calls in the home to make an emergency call. It does not matter if a telephone is off the hook, or a line is busy, the security panel will take control and make an emergency call. For telephone line seizure to work correctly, the phone lines need to be routed into the security panel before they enter the home. Academic Business Consultants Chapter 12, Security Systems Page 17

18 Alarm Signal Formats Your alarm will take the following steps when a security event is triggered: 1. An alarm sounder will alert everyone in the home. 2. The home s occupants will usually have a few seconds to turn off the system in the event of a false alarm. 3. The alarm system will seize the phone lines in the home. 4. The alarm system will dial the monitoring station. 5. Your account number will be sent. 6. The type of event fire, burglary, panic, medical will be sent to the monitoring station. 7. After the account information and alarm signal have been sent, the alarm call will be disconnected from the monitoring station. 8. After approximately 4-15 seconds, a voice line is opened between the monitoring station and the home. 9. An operator at the monitoring station will talk with whoever is at the home. The operator may ask for a secret code, and will only stop sending emergency services if the correct code is given. 10. In the event of a burglary alarm, the operator may send the police without calling the home. To send and receive information, the home s alarm system and the monitoring station must use the same alarm signal format. The most common alarm signal formats include: pulse, touch-tone, and Frequency-Shift Keying (FSK). Pulse Pulse uses audible clicks to send information. The pulse format is very reliable even on noisy telephone lines. However, the pulse format is slower and sends less information than touch tone and FSK formats. Touch-Tone Touch-tone is a Dual-Tone Multi-Frequency (DTMF) technology. DTMF uses tones, instead of audible clicks, to send information. DTMF can send more information than pulse, and is faster than pulse. DTMF is often called Contact ID. Contact ID is a DTMF-based alarm format that was developed by the security company, Ademco. Ademco is now part of the Honeywell Corporation. In most installations, DTMF has replaced the pulse dialing protocol. FSK FSK is a digital technology that uses 0s and 1s to transmit information. FSK can keep a signal clean even in environments with electrical noise. FSK is also known as Security Industry Association (SIA) and SIA 2. Academic Business Consultants Chapter 12, Security Systems Page 18

19 (Figure, Alarm System Signal Formats) Academic Business Consultants Chapter 12, Security Systems Page 19

20 Backup Systems Phone lines are used to connect most home security systems to central monitoring stations. In a storm, the phone lines may be down and the security system will not be able to make an emergency call. Also, if the power is out, the security panel will be turned off. Fortunately most security systems have backup systems. Most security panels include an uninterruptable power supply (UPS) that takes over when the power goes out (See figure a). Some security systems use an internal cell phone to make emergencies calls when either a POTS or VoIP phone line goes out (See figure b). There are even some systems that can bypass the phone system entirely, and are able to use long-range radio signals to send an alarm signal (See figure c). (Figure a, UPS Battery in a Security Panel) (Figure b, Flash Animation, the student will turn off the home s power, but the security system will stay lit. As the student rolls-over each security event (fire, CO, medical and burglary) the cell phone will dial the central monitoring station.) Academic Business Consultants Chapter 12, Security Systems Page 20

21 (Figure c, Security Panel with Long-Range Radio Transmitter) Academic Business Consultants Chapter 12, Security Systems Page 21

22 Door Strikes Door strikes are electronic locking devices that are placed on exterior gates and doors to control access to the home (See figure a). Door strikes are also known as electronic deadbolts and magnetic locks. With a door strike, an alarm is activated after the door is closed. The door can be opened, and the alarm can be turned off, with a variety of access devices including: keypads, keyfobs, biometric readers, and card readers. In many homes the door strike is independent of the home s central alarm system. This allows the gate or door to be accessed, and then the central alarm system can be turned on or off. This type of installation helps prevent false alarms. (Figure, a, Door Strike Lock) Keypad A keypad is one of the most popular methods of accessing a door with a door strike (See Figure b). When the alarm code is pressed into the keypad, the door strike unlocks the door and the alarm is turned off. Most keypads include a delay feature. If the door is opened with a key, the user has to enter a security code into the keypad to disarm the alarm. This must be done in a predetermined amount of time. Most installers set the alarm delay for 45 seconds. (Figure b, Keypad Alarm Setting) Academic Business Consultants Chapter 12, Security Systems Page 22

23 Keyfobs A keyfob is a convenient method to open doors with electronic locks, especially when people come and go frequently (See figure c). With a keyfob, the user does not need to enter a code on the keypad. Many keyfobs include a panic button for emergencies. (Figure c, Keyfob Access Control) Biometric Readers Biometric readers recognize users based on physical traits such as eye retinas, facial patterns, and fingerprints (see figure d). Biometric readers are considered to be more secure than other access devices. With biometric devices, you do not need to worry about changing codes on a periodic basis. Biometric readers are still cost prohibitive for most home security systems. However, their cost is declining and they are becoming more popular. (Figure d, Biometric Reader) Academic Business Consultants Chapter 12, Security Systems Page 23

24 Card and Proximity Readers Card and proximity readers have been used to open doors in commercial settings for many years. Card readers are now used in some homes. Card and proximity readers are magnetized with the home s access code. The code is read by the card reader and the door is opened. A card reader makes direct contact with the card (See figure e). Proximity cards just need to be close to the reader; usually within a few inches (See figure f). (Figure e, Card Reader) (Figure f, Proximity Reader) Academic Business Consultants Chapter 12, Security Systems Page 24

25 Intrusion Sensors Intrusion sensors are placed throughout the home to monitor security events. Intrusion sensors are connected to the security panel for automated alarm triggering and remote monitoring. The following intrusion sensors are installed in many home security systems: Driveway Alarms Driveway alarms are early warning devices that detect vehicles that enter your property (See figure a). Driveway alarms consist of a transmitter and a receiver. Transmitters are located near the driveway, and the receiver is located in the home. When a vehicle enters the property, the transmitter sends a signal to the receiver and activates a light and/or an alert sound. There are two detector technologies used in driveway alarms: IR and magnetometer. IR driveway alarms look for heat. IR detectors can create false alarms when animals get close to the transmitter. Magnetometer detectors are activated when a large metal object nears the transmitter. Driveway alarms can be installed as stand-alone devices or they can be connected to the security panel. (Figure a, Driveway Alarm Detector) Glass-Break Sensors Glass-break sensors detect the sound and shock wave of breaking glass. Glass-break sensors are mounted on, or near, a window (See figure b). When a glasssensor hears and feels glass breaking, it sends a signal to the control panel and triggers the security system. Many glass-break sensors are wireless devices. (Figure b, Glass-Break Sensor) Academic Business Consultants Chapter 12, Security Systems Page 25

26 Magnetic Switches A magnetic switch is a two-part device that is use to detect when windows and doors are open. One part of the magnetic switch is attached to the door or window jam. The other part of the switch is placed on the door or window. When the two parts of the switch are separated, an alarm is triggered (See figure c). Most magnetic switches will automatically trigger a call to a central monitoring station. Magnetic switches are also called window and door sensors. (Figure c, Magnetic Switches) Personal Panic Button If someone inadvertently opens the front door to an intruder, the security systems will not work. A personal panic button is a hand held device that can be used to manually trigger an alarm. Personal panic buttons can also be used by people with medical conditions. Most personal panic buttons are connected to the security panel using a wireless connection (See figure d). (Figure d, Personal Panic Button) Academic Business Consultants Chapter 12, Security Systems Page 26

27 Passive Infrared Motion Detector (PIR) A PIR is an electronic device that detects body heat. Most PIR detectors are designed to be turned on when the home is unoccupied. Many people do not use PIRs because they are concerned that their pets will trigger a false alarm. However, there are some PIRs that are "pet immune". Pet immune PIRs can be adjusted for animals that weigh up to 100 lbs (See figure e). (Figure e, Pet Immune PIR) Pressure Pads Pressure pads use a switch that is normally open. When weight is placed on the pressure pad, the switch is closed and an alarm is triggered. Pressure pads are not always used to trigger an alarm. Pressure pads can be used on a walkway to open a gate, and to turn on a camera. Pressure pads can be also be used next to a bed to trigger a light. (See figure f) (Figure f, Pressure Pad) Academic Business Consultants Chapter 12, Security Systems Page 27

28 Photoelectric Sensors Most sensors are used to detect intruders. Photoelectric sensors are often used protect people in the home. Photoelectric beam sensors are commonly used to detect objects in the path of a motorized gate or door. Photoelectric sensors include a transmitter and a receiver. The transmitter sends a narrow light beam to a receiver. If the light beam is received the door s motor will close the door. If the light beam is broken by an object, a signal is sent that stops the door s motor. The light beam is usually a low powered laser light. Photoelectric beam sensors are more sensitive, and work faster than motion sensors. Photoelectric beam sensors are also known as light sensors. Photoelectric sensors are commonly used with motorized garage doors. Garage doors with motors can be dangerous when they close; especially when children are present. With a photoelectric sensor if the garage door is closing, and a child crosses the path of the door, the motor will stop (See figure ). In many systems if the light beam is broken, the garage door stops closing, and then opens all the way. (Figure , Photoelectric Beam Sensor) Academic Business Consultants Chapter 12, Security Systems Page 28

29 Wired Smoke Detectors Stand-alone smoke detectors are effective to warn people of a fire when they are home. However, stand-alone smoke detectors are not able to contact the fire department when smoke is detected. Wired smoke detectors are connected directly to the security panel, and can automatically send an alarm signal to the fire department. Wired smoke detectors are usually powered directly from the security panel and do not use batteries. In the event of a power failure, the security panel s uninterrupted power supply UPS will energize the smoke detectors. The most common voltage for smoke detectors is 12-volts DC. Wired smoke detectors have several advantages. With wired smoke detectors the wiring can be simplified. It is common for several smoke detectors to be wired together, and then one wire is run to the security panel. Also, some wired smoke detectors include a polarity reversing relay (See figure a). With this type of relay, when one alarm is triggered, all of the alarms on the same circuit will be triggered. (Figure12.2.9a, Polarity Reversing Relay) Wired smoke detectors can look for wiring problems in their own circuit. At the end of each circuit, is a device that is called an end-of-line (EOL) resistor. The EOL resistor is placed after the last smoke detector in the circuit (See figure b). If a wiring problem occurs, the security panel won t see the EOL resistor and the system will trigger a trouble signal. When a security panel enters this condition, it will notify a central monitoring station and a technician will be sent to correct the problem. (Figure b, EOL Resistor) Academic Business Consultants Chapter 12, Security Systems Page 29

30 Some smoke detectors us a four-wire supervisor relay (See figure c). Supervisor relays have the same purpose as an EOL resistor and are sometimes called end-of-line relays. A supervisor relay is installed on the last smoke detector in the system. A break in the power circuit will cause the security panel to produce a trouble signal. (Figure c, Supervisor Relay) Academic Business Consultants Chapter 12, Security Systems Page 30

31 12.3 Security Cameras Security cameras allow you to monitor events while they are happening, and record events when you are not home. Home security cameras can be viewed on a television. Cameras can also be connected to the internet, and their video can be seen on a home computer or on the internet. Some cameras are used with the home s intercom system. You can see who is at the front door before you open it (See figure 12.3). Home camera systems are often used to record video to a digital video recorder (DVR), and are played back when you suspect unusual activities. Be careful of terms that are used with security cameras. They can be confusing at times. A video system that is designed for a small group of people is often called a Closed-Circuit Television (CCTV). The term CCTV is also used to describe small video installations. In this section we will cover the types of cameras that are found in home security systems, their operations, and how activities are recorded. (Figure 12.3, Intercom with Video Display) Academic Business Consultants Chapter 12, Security Systems Page 31

32 Camera Types There are three types of cameras used in home security systems: analog, IP, and hybrid. The main difference between these cameras is in how they distribute video signals. The output of an analog camera is designed to go into a video display such as a television. Analog cameras are typically connected to video displays using a coax cable. However, there are now some analog cameras that use Cat5 cables. The output of an IP camera is designed to be connected to a home s local area network (LAN). IP cameras digitize analog video signals before they are transmitted. IP cameras are connected to the network using a Cat5 cable. IP cameras can be viewed on a computer using a web browser. A hybrid camera offers both analog and IP outputs, and can use either coax or Cat5 cables (See figure a). (Figure a, hybrid camera) Most security cameras use either a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) sensor. CCD and CMOS sensors are electronic chips that captured light, and convert it into a video signal. CMOS sensors use less power than CCD sensors (See figure b). However, CCD sensors create a clearer picture, and work better in low light conditions. (Figure b, CMOS chip) Academic Business Consultants Chapter 12, Security Systems Page 32

33 Camera Specifications To be an effective installer you should be aware of camera specifications. You should always be able to match a client s needs with the right camera equipment. You should be able to describe the following camera specification: lens type, lux rating, and resolution. You should also be able to describe the differences between black and white (BW) and color cameras, and how each one functions in low light environments. Lens type If you have ever used a digital camera you know that you can zoom in, and out, on an object. When you zoom in and out you are changing the camera s focal length. A short focal length gives you a wide field of view, but you are not able to see the details of a particular object. A long focal length allows you to see the details of an object, but your field of view will be narrow. Security cameras are designed to be installed in a fixed position, and to observe one area. The type of lens that you choose for a security camera will depend on how far the camera is from the area being observed, and the amount of detail that you need. The focal length on a security lens is measured in millimeters (MM), and range from approximately 3.6mm to 18mm. Many cameras lenses can be changed. If the wrong lens is installed when the camera is mounted, it can easily be exchanged (See figure a). If the lens cannot be changed, you will need to switch the camera to change the focal length. (Figure a, Flash animation: the student changes the lens from 3.6mm to 8mm, to 12mm to 18mm. As the student puts on a higher mm lens they zoom in on the object. As the student reduces the size of the lens (smaller mm lens) they zoom out from the object.) The iris in a camera lens works like the pupil in your eye. When light is low your pupil will open to let in more light. If a camera is to be installed in low light conditions, its iris many need to be opened by hand. Some cameras are capable of adjusting the iris automatically. Cameras installed outside the home will need to adjust for day and night light conditions, and may need an auto-iris lens. Academic Business Consultants Chapter 12, Security Systems Page 33

34 Lux rating Cameras are rated on how well they work in low light environments. Light is measured in lux. A camera with a lux rating of 2 can create clear pictures using the light from a 40W bulb. A camera with a lux rating of 0.5 will be able to make out images at night. Some cameras have a lux rating of.001, and are designed for night viewing. (See figure b) (Figure b, Low Light Camera) Resolution Resolution refers to the clarity of the video picture. Clearer pictures allow you to see more details. Resolution is measured in the number of horizontal lines a camera can reproduce. The higher the number of horizontal lines, the clearer the picture will be. A typical camera picture resolution is around 350 to 400 lines. Some high-end home security cameras can reproduce almost 500 horizontal lines (See figure c). High resolution cameras also allow you to zoom in on a particular object without losing any details. (Figure c, High Resolution Camera) Academic Business Consultants Chapter 12, Security Systems Page 34

35 Power Requirements Most security cameras are powered with either a 12-volt DC, or a 24-volt AC electrical connection (See figure d). 24-volt AC is often used in installations where cameras are installed over 100 feet from their power source. Some cameras are capable of accepting both 12-volt DC and 24-volt AC connections. To conserve energy some cameras will go into a sleep mode if they do not sense motion for 20 minutes. (Figure d, Camera with 12-volt DC Power Connector) Infrared (IR) Illumination IR illumination cameras are used where there is not enough light to create a clear picture. IR cameras use a series of light emitting diodes (LED) to transmit IR light (See figure, e). An IR camera emits IR light, and then picks up the reflections from the IR illuminated subject. People are not able to see the light from IR emitters. (Figure e, IR Illumination Camera) Academic Business Consultants Chapter 12, Security Systems Page 35

36 Black and White or Color Cameras For many years black-and-white cameras (B/W) were installed in homes because they were less expensive than color cameras. However, the cost of color cameras has dropped considerably, and most installers now recommend color over B/W cameras. Color cameras allow you to see more details (See figure f) during the day. With a color camera your will be able to tell the police that the man, was wearing a blue coat. However, the human eye, and a color camera, loses its ability to see color at night. B/W cameras see better at night. At night a B/W camera can delete color information, open its iris, and focus on objects. From dusk to dawn, many color cameras will automatically switch to a B/W mode. Some color cameras include IR emitters that are able to create clear color pictures during the day and detailed B/W pictures at night. B/W cameras are also called monochrome cameras. (Figure f, B/W Camera Output) Academic Business Consultants Chapter 12, Security Systems Page 36

37 Locating Cameras They type of camera you install depends on where it is installed. Exterior cameras are usually located near entrance doors. Exterior cameras need to be in an enclosure that protects them from tampering, moisture, and extreme temperatures. Some cameras are able to Pan, Tilt, and Zoom (PTZ). Pan allows the camera to move from side to side. Tilt allows the camera to move up and down. Zoom allows the camera to move in on, and away from, a particular object (See figure a). (Figure a, PTZ Camera Movements) PTZ cameras are rare in homes. Most home exterior cameras are fixed to a wall, and their camera angle is adjusted by hand. Exterior cameras for homes usually fit into one of two categories: bullet or dome. Bullet cameras are shaped like a cylinder. Bullet cameras are typically 2 to 6 inches long (See figure b). Dome cameras get their name from a protective plastic covering that is designed to prevent tampering. The camera s protective covering looks like a dome (See figure c). Bullet and dome cameras are easy to install and configure. They usually include a lens, mounting brackets, and screws. Many bullet cameras include IR LED emitters for night viewing. Bullet and dome camera lenses are usually optimized to view objects that are 10 to 20 feet from the camera. Lenses can be easily exchanged for custom applications. (Figure b, Bullet Camera) Academic Business Consultants Chapter 12, Security Systems Page 37

38 (Figure c, Dome Camera) Inside the home, cameras can be mounted in a wall and covered with a plate (See figure d). The size of cameras has been reduced in recent years, and some interior cameras are so small they can be hidden in furniture, electronics, and even toys. Hidden cameras are commonly called, nanny cams (See figure e). (Figure d, Interior Camera with Wall Plate) (Figure e, Nanny Cam) Academic Business Consultants Chapter 12, Security Systems Page 38

39 Camera Viewing The output of a camera on a CCTV system is usually viewed in one of three ways: video monitors, computers on an IP network, or using RF signals. Video Monitors Some cameras can be directly connected to a video monitor. A video monitor looks like a television. However, monitors do not have built-in tuners and are not able to view television stations. Security cameras are usually connected to a video monitor using coax or composite video cables. (Figure a, Security Monitor with Coax and Composite Inputs) Academic Business Consultants Chapter 12, Security Systems Page 39

40 IP Networks Many cameras are now IP-enabled, and can be installed on the home s local area network (LAN). The video from an IP camera can be viewed on any computer that is on the same LAN. IP-enabled cameras can also be configured so their video can be seen over the internet. Cameras are usually connected to the home s LAN with Cat5 cable. The camera s video output is viewed on the computer by using a web browser (See figure b). (Figure b, IP-enable Camera Output) Academic Business Consultants Chapter 12, Security Systems Page 40

41 RF Signal Security cameras may also be connected to the home s televisions. With this approach the camera signal is converted to a television channel that is not used. To view a camera s signal, the user switches the television to the channel that the camera is using. If more than one camera is used, the output of each camera can be given its own channel. Multiple cameras can also be viewed on one channel using a technique called tiling (See figure, c). (Figure c, Video Tiling) To use a camera on a particular channel, video signals from other sources need to be blocked with a notch filter. A notch filter is a device that blocks unwanted video. A notch filter can block video from antennas, satellites, and cable sources (See figure d). Channels on either side of the camera channel are also blocked to eliminate interference. As an example, a notch filter may block channels In this example, we are able to use channels 65, 67, and 69 for cameras. Channels on either side of the camera channel are left blank to eliminate interference. In our example, channels 64, 66, 68, and 70 are not used. (Figure d, Notch Filter) Academic Business Consultants Chapter 12, Security Systems Page 41

42 Recording Intrusions Imagine being able to see everything that happened in your home, even when you are away. You could see who came to your door, or who was in your yard, and you could monitor your teenager s friends all while you were away. If you have a CCTV system it is an easy to record all the events that take place in your home. The most common method of recording events is to use a digital video recorder (DVR). A DVR is a specialized computer system that contains a hard drive, and is designed to store and playback video. The size of the hard drive will determine how much video you are able to store. As a reference, a 100 GB hard drive will allow you to store approximately five days of video from one camera. If you have more than one camera you may need a larger hard drive. System with multiple cameras may use a recording technique that is known as multiplexing. Multiplexing takes the output of several cameras and divides their video into smaller pieces before it records them to the DVR. When playing video back on a multiplexing system the video may seem a bit choppy, but all of the video will be there. If an alarm is triggered on one camera, a multiplexing system will give priority to that camera, and will record most, or all of its video. Some DVRs are IP enable and their output can be seen over the internet. (See figure ) (Figure , Home Security Recording System) Academic Business Consultants Chapter 12, Security Systems Page 42

43 12.4 Security System Infrastructure The system that connects security sensors, alarms, and other devices is known as the infrastructure. The infrastructure is often referred to as the backbone of the security system. A security system is only as good as its weakest link. Too often the weakest link in a security system is the infrastructure. Poor workmanship, and failure to follow standards and codes, are the biggest causes of infrastructure problems. Standards are usually associated with industry practices. Codes are usually associated with laws that govern the construction industry. Installers who adhere to industry standards and building codes rarely have problems (See figure 12.4). Installing security systems without standards is dangerous. What would happen if you installed a fire alarm system that did not meet code? If a fire occurred people could be injured, or worse, and you could be charged with a criminal offense. In this section we will discuss wired and wireless infrastructures. The following industry standards, and trade organizations, work with government agencies to create building codes. Standards Organizations British Standard (BS) Standard 4737 National Electrical Code (NEC) Chapter 1 Security Industry Association (SIA) Papers on access control, alarm monitoring, CCTV, fire detection, and home automation Underwriters Laboratories (UL) Standards 681, 1641, 1076 Trade Organizations National Supervisory Council for Intruders and Alarms (NSCIA) UK based codes and practices trade organization National Burglar and Fire Alarm Association Standard (NBFAA) US based trade organization (Figure 12.4, Security Wiring) Academic Business Consultants Chapter 12, Security Systems Page 43

44 Wired Security Infrastructure To install a security system you should be familiar with basic wiring requirements and workmanship standards. The following security infrastructure standards are common to most local building codes: Keypads, magnetic contacts, and other security devices are connected to a security panel using 22 gauge wires. Security devices with a sounder must use 16 gauge wires for their power supply. All wiring should be installed where it won t be damaged. Run wiring in the shortest, most economical, and best-concealed route available. Security wiring should be placed in conduit where it crosses support beams. Wiring should be tape-protected if it comes in contact with sharp corners. Wiring should be run over, not under, piping. Security wiring needs to be spaced 2 inches or more from power cables. Security wiring can be run next to power cables if it is run through protective conduit. Wiring should be protected with tape if it passes through wood floors and walls. Wire should not be run near equipment that produces electromagnetic interference (EMI). All wires that are run through an HVAC system must be plenum rated. In construction, a firewall is a fire-resistant wall that is designed to slow the spread of fire from one room to another. All wiring that passes through a firewall must be sealed with fire-stop material (See figure ). Some local building codes have more stringent requirements than others. Always check local building codes before you start a project. (Figure , Sealing a Firewall) Academic Business Consultants Chapter 12, Security Systems Page 44

45 Wireless Security Infrastructure It is hard to wire existing homes for a new security system. For many years, installers would not use wireless systems because they were concerned with their reliability. However, wireless systems have matured. Wireless security systems are now installed in many homes, especially by do-it-yourself (DIY) users. The following systems are commonly found in wireless security systems: Carbon Monoxide Flood Detectors Humidity Sensors Keypads Light Control Modules Motion Detectors Panic Button Smoke Detectors Temperature Sensors Window Sensors All wireless devices need batteries. Wireless security devices can send their battery level and operational status to a security panel. In a wireless system, there are no wires run to the security panel (See figure ). This allows the security panel to be placed anywhere in the home. Some security systems are based on X10 technologies. An X10 security system uses the home s AC power wiring and is considered to be a hybrid system. (Figure , Wireless Security System) Academic Business Consultants Chapter 12, Security Systems Page 45

46 12.5 Troubleshooting Security Systems False alarms are a big problem. In some cities over 90% of the fire and burglar alarms are false emergency services respond to all of them. Many cities fine homeowners who have had too many false alarms. False alarms also create a problem of confidence. Police and neighbors may ignore, or respond slowly, to a home that has a history of false alarms. The list below should be adhered to by all installers to reduce the number of false alarms: Preventing False Alarms: Use a licensed contractor with a proven track record to install all alarm systems. Keep all security equipment manuals in a place where they can be easily accessed. Install all alarms using 22 AWG conductors or greater. 22 AWG wire is the National Burglar and Fire Alarm Association Standard. Cat5 cable uses 24 AWG conductors and cannot be used to connect sensors to alarms. Use two sensors on the same security zone where possible. For example, use two magnetic switches on a window. Both magnetic switches are needed to sense an event and trigger the alarm. Program door alarm sensors for a 45 second delay, or greater, to give people time to disable the alarm. Keep small children away from panic buttons. Inspect alarm systems every year. Inspect motion detectors, and door and window contacts for dust, spider webs, moisture, or anything that might interfere with a sensor s operation. Replace all batteries twice a year. Investigate false alarms to determine what caused them. Have equipment that triggered the false alarm repaired or replaced. Be sure that the alarm panel is plugged in to a power outlet that cannot be switched off. If the power is out for more than 10 hours, the UPS battery may be drained. Be sure to call your monitoring service if this occurs. Make sure to cancel all false alarms immediately to prevent the arrival of emergency services. Academic Business Consultants Chapter 12, Security Systems Page 46