Alarm Systems and Smoke Alarms

Question 1

There are two categories of intrusion sensing devices, what are these?

Answer 1

• Perimeter devices
• Interior devices.

Question 2

What are three common perimeter devices?

Answer 2

• Magnetic reed switches
• Roller ball contacts
• Glass break detectors.

Question 3

When installing a magnetic reed switch, what must be ensured?

Answer 3

Proper positioning of the magnet to avoid nuissance tripping.

Question 4

What is the prime disadvantage of roller ball contacts when compared to magnetic reed switches?

Answer 4

Cost to produce is higher, since roller ball contacts are a mechanical device.

Question 5

Could very small conductors be run with window screening to alarm against ripping or cuts of the screen?

Answer 5

Yes, this makes an open window much more secure.

Question 6

What triggers a dual technology glass break detector?

What must be ensured when installing one?

Answer 6

Acoustic sound pattern of glass breaking and acoustic shock waves due to a rapid pressure change.

The device must be mounted in line of sight to minimize acoustic muffling.

Question 7

What are two common internal device technologies used in security systems?

Answer 7

• Passive infrared detectors
• Microwave motion detectors.

Question 8

When installing wireless alarm devices, what must be ensured?

Answer 8

A path unobstructed by metal ducting, to maintain signal fidelity.

Question 9

Typically, where should one install signal devices for a security system?

Answer 9

In a relatively inaccessible place like a cold air return or attic space; this amplifies the acoustic quality and minimizes tampering.

Question 10

The CPU of a typical alarm system operates on a “_____” voltage and has a “_____”.

Answer 10

• Low AC.
• Battery backup.

Question 11

Zone loops can be programmed in three ways; what are these?

Answer 11

• Normally open loop
• Normally closed loop
• Monitored loop.

Question 12

What is a monitored loop?

Answer 12

One which uses an end of line resistor to monitor a small current through the circuit.

Question 13

What are sirens typically rated in?

Answer 13

Wattage and decibel output.

Question 14

What is a signal device?

Answer 14

A device which produces an audible or visible signal to alert people of a problem.

Question 15

What size aluminum wire should be used when wiring an alarm system?

Answer 15

Only copper may be used in a class 2 circuit.

Question 16

There are two common technologies for smoke detectors, what are these?

Answer 16

• Ionization or product of combustion
• Photoelectric or light obscuration or projected beam

Question 17

Which smoke alarm would be better at detecting a large flaming fire with little smoke?

Answer 17

Ionization type are faster at detecting these types of fire.

Question 18

In a single dwelling where are smoke alarms installed?

Answer 18

• On every storey
• Every sleeping room
• In hallways between sleeping rooms.

Question 19

Should all smoke alarms be interconnected?

Answer 19

Generally yes.

When adding new alarms they must all be interconnected with each other but not necessarily with the old system.

Question 20

What are the four conditions in which a fire alarm system could display?

Answer 20

• Normal
• Trouble
• Alarm
• Supervisory.

Question 21

Which 3 components must a basic fire alarm system contain?

Answer 21

• A control unit for logic processing,
• A manual pull station
• An audible signal device.

Question 22

What is supervisory current used for in an alarm system?

Answer 22

To continuously monitor the interconnection of devices and anunciate any faults in the wiring.

Question 23

What is a class B fire alarm circuit?

Answer 23

One which uses an end of line resistor.

Question 24

What is a class A alarm circuit?

Answer 24

One which terminates back at the panel and creates two closed loops.

Question 25

Could two or more wires be connected to any one terminal on fire alarm equipment?

Answer 25

No, only one wire per terminal, every time.

Question 26

What technology’s basic principles were a large part of the development of motion detectors?

Answer 26

Radar