Power Supplies

Question 1

Choose which occupancy is matched correctly with its main protection design goal. 1. Warehouse for women’s clothing - Mission continuity 2. Manufacturing Facility - Property protection 3. Assisted living complex - Mission continuity 4. Military missile site computer room - Heritage preservation 5. Art museum at Yale University - Mission continuity

Answer 1

2. Manufacturing Facility - Property protection

Question 2

Primary power supplies for a fire alarm system must be reliable and: 1. connected to a circuit protected by a ground fault device. 2. connected to the local power utility. 3. backed up by a generator. 4. dedicated to the fire alarm system.

Answer 2

4. dedicated to the fire alarm system.

Question 3

Fire alarm systems connected to normal or emergency power supplies must be connected to the building power system through the use of a: a. Non-switched circuit b. A non-recycling electrical relay c. A dedicated branch circuit d. A direct connection to the secondary side of a transformer

Answer 3

c. A dedicated branch circuit

Question 4

At times, the fire alarm system may require an uninterruptible power supply (UPS). It will _________ be required ___________ 1. always…if the panel can’t be reset within 10 seconds. 2. not…when the primary power supply is commercial light and power and the secondary power supply is 24 hour battery backup. 3. always…if the system’s primary power supply is unreliable. 4. always…if the system uses a generator for the primary power supply.

Answer 4

2. not…when the primary power supply is commercial light and power and the secondary power supply is 24 hour battery backup.

Question 5

Component compatibility can always be checked by contacting 1. The authority having jurisdiction. 2. Underwriters Laboratories or FM Global. 3. The installer of the system. 4. The maintainer of the system

Answer 5

2. Underwriters Laboratories or FM Global.

Question 6

A single power supply is required to power all control units in a single complex, no matter where they are located. 1. True 2. False

Answer 6

2. False

Question 7

Secondary power for new fire alarm systems without voice capability must have the ability to power the fire alarm system for a period of at least: a. Fifteen minutes in quiescent mode followed by 15 minutes in full alarm. b. 60 hours in quiescent mode followed by 5 minutes in full alarm. c. 24 hours in quiescent mode followed by 5 minutes in full alarm. d. 24 hours in quiescent mode followed by 20 minutes in full alarm.

Answer 7

c. 24 hours in quiescent mode followed by 5 minutes in full alarm.

Question 8

You find the electrical installation prints and notice that the fire alarm primary power circuit is shown on the plans as being connected to the same circuit to which the electronic data processing equipment is connected. This is supposedly a very secure circuit. Is this an allowable arrangement? a. Yes, as long as the circuit is backed up by the generator in the building. b. Yes, because the circuit is very secure. c. No, because the fire alarm control circuit can’t be connected to any other circuit that controls electronic equipment, such as computers and information technology equipment. d. No, because the fire alarm circuit has to be a dedicated branch circuit.

Answer 8

d. No, because the fire alarm circuit has to be a dedicated branch circuit.

Question 9

If the fire alarm system’s battery charger fails, the fire alarm system shall transmit a 1. Supervisory signal. 2. No signal. 3. Alarm signal. 4. Trouble signal.

Answer 9

4. Trouble signal.

Question 10

The batteries can be eliminated from the protected premises fire alarm system when: a. The fire alarm system is not used for other fire safety purposes, such as door closure and elevator recall. b. Two or more generators are provided for emergency power to the building. c. The generator providing secondary power starts automatically. d. Never. The building fire alarm system always requires batteries.

Answer 10

d. Never. The building fire alarm system always requires batteries.

Question 11

The contractor searches with you for the point where the alarm panel power supply will be connected. The contractor turns to you and says, “In the past, I’ve just used any circuit in the building.” You know this isn’t correct, and list for him the points that need to be followed. Which of the following points should be on your list? A. The circuit has to be dedicated to only the fire alarm system B. The circuit control has to be inaccessible to unauthorized people C. The circuit breaker has to be marked clearly in any contrasting color D. The location of the circuit-disconnecting device, probably a circuit breaker, has to be clearly noted at the fire alarm control unit 1. A, C, and D. 2. A, B, and C. 3. A, B, and D. 4. B, C, and D. 5. All of the above are needed

Answer 11

3. A, B, and D.

Question 12

Fire alarm system batteries have to be marked with the date of their installation in the month/year format. a. True b. False

Answer 12

b. False (They must be marked with the date of manufacture)

Question 13

It’s a large system and it needs a large secondary power supply. A number of generators are on the property, and none meet the requirements of NEC Articles 700, 701, or 702. If one of them is to be used for the secondary power supply, are batteries still required? 1. Yes, 4 hour “float” batteries are required. 2. Yes, 24 hours of battery backup are required. 3. Yes, 30 minutes of connected reserve batteries are needed. 4. No, battery backup of any kind is not required.

Answer 13

1. Yes, 4 hour “float” batteries are required.

Question 14

You see that a single generator has been provided for the site, and indications are that the generator is providing standby power for the fire alarm system. You also can’t find any batteries for the system. Is this an acceptable installation? a. Yes, as long as the generator is automatic starting and connected to the secondary inputs in the fire alarm panel. b. Yes, as long as the generator has “load shedding” abilities, so the fire alarm system is always connected to the generator in the loss of normal power condition. c. No, because even with a generator, “float” batteries are required. d. No, because generators not dedicated specifically to the fire alarm system are not allowed to be connected to the fire alarm system power supply

Answer 14

c. No, because even with a generator, “float” batteries are required.

Question 15

Which of the following statements are correct? A. The fire alarm circuit-disconnecting device has to be marked in red. B. The fire alarm circuit-disconnecting device must be accessible to all employees of the facility. C. The location of the fire alarm circuit-disconnecting device has to be noted at the fire alarm control panel. D. The fire alarm circuit-disconnecting device has to be in a locked cabinet. 1. A & B. 2. A & C. 3. B & C. 4. C & D.

Answer 15

2. A & C.

Question 16

A fire alarm system providing central station service has to have secondary power capable of operating the system for a period of 1. 24 hours in standby mode, followed by 2 hours of emergency operation. 2. 48 hours in standby mode, followed by 1 hour in alarm condition. 3. 24 hours in standby mode, followed by 15 minutes in alarm condition. 4. 24 hours in standby mode, followed by 5 minutes in alarm condition.

Answer 16

4. 24 hours in standby mode, followed by 5 minutes in alarm condition.

Question 17

The equipment vendor says that if power is lost to the control unit, even if configured as described in the previous question, there still may be a loss of signals. How does this impact the system power supply? 1. Special nickel-cadmium batteries are the only type you can use. 2. No impact; a loss of signals is acceptable if it’s for no longer than 30 minutes. 3. The power supply has to be backed up by a generator. 4. NFPA 72 provides that signals cannot be lost, so a UPS with a minimum capacity of 24 hours in standby mode, and the ability to carry full system load for 15 minutes, will be required

Answer 17

4. NFPA 72 provides that signals cannot be lost, so a UPS with a minimum capacity of 24 hours in standby mode, and the ability to carry full system load for 15 minutes, will be required

Question 18

Which of the following is a permitted means of providing a secondary power supply for a fire alarm system? 1. A manual starting generator. 2. Multiple manual starting generators. 3 An automatic starting generator. 4. An automatic starting generator and 4 hours of batteries.

Answer 18

4. An automatic starting generator and 4 hours of batteries.

Question 19

Secondary power to a fire alarm control unit 1. cannot be eliminated. Elimination of the secondary power supply is not permitted. 2. can be eliminated if connected to a generator that meets the requirements of NFPA 70, Article 695. 3. can be eliminated if connected to a power supply that meets the requirements of NFPA 70, Articles 725 and 760. 4. can be eliminated if connected to a generator that meets the requirements of NFPA 70, Article 700 or 701.

Answer 19

1. cannot be eliminated. Elimination of the secondary power supply is not permitted.

Question 20

The requirements for the power supply for a fire alarm system are found in the _______ chapter of NFPA 72 a. Notification Appliances b. Protected Premises fire alarm system c. Fundamentals of fire alarm systems d. Component selection for fire alarm systems

Answer 20

c. Fundamentals of fire alarm systems

Question 21

For years your company has used a generator for backup power. Can this generator act as a replacement for the batteries that the contractor says will be needed in the new fire alarm control panel? 1. No, not in any arrangement. 2. If the owner chooses to re-design the generator arrangement to meet the requirements of NFPA 70 Article 702, also meeting the requirements of Articles 700 or 701. 3. Simply as a back-up to primary power. 4. Only if a two-day battery supply is also provided

Answer 21

1. No, not in any arrangement.

Question 22

Based on the requirement for the system (the system uses horns and strobes) to meet all the requirements for central station service, what are the time requirements that the secondary power must meet? 1. 60 hours standby, followed by 5 minutes in alarm. 2. 24 hours standby, followed by 10 minutes in alarm. 3. 60 hours standby, followed by 10 minutes in alarm. 4. 24 hours standby, followed by 5 minutes in alarm.

Answer 22

4. 24 hours standby, followed by 5 minutes in alarm.

Question 23

A secondary power supply should be able to provide power to the protected premises fire alarm system in no longer than _______ seconds when the primary power supply fails.

a) 5
b) 10
c) 30
d) 60
e) 99
f) 120

Answer 23

b) 10

NFPA 72 (2016)

10.6.6.1 The secondary power supply shall automatically provide
power to the protected premises system within 10 seconds
whenever the primary power supply voltage is insufficient for
required system operation.