Combustion Ignition and controls

Question 1

Why are Combustion/Ignition controls designed to react quickly?

Answer 1

To prevent an accumulation of unburned fuel in a combustion chamber

Question 2

Which of the following would be considered an operating control?

Thermostat
limit switch
fan control
fuel control valve
a and b

Answer 2

Thermostat

Question 3

Older combustion safety control systems utilize flame rectification systems.

T or F

Answer 3

F

Question 4

The voltage produced by a thermo-electric device is dependent upon;

Answer 4

The temperature difference between the hot & cold junction

Question 5

Flame rectification relies on flame;

Answer 5

Conductivity

Question 6

The only portion of the ac signal that conducts current during rectification is the swing.

Answer 6

positive

Question 7

For flame rectification to be effective the surface area of the ground conductor must be a minimum ratio larger than the flame rod.

Answer 7

4:1

Question 8

Flame rectification systems operate the best when the surface area of the ground conductor is a ratio larger than the flame rod.

Answer 8

10:1

Question 9

The flame scanner that detects light wavelengths that are able to be seen by the human eye is/are?

UV
visual
IR
B and C

Answer 9

Visual

Question 10

The flame scanner that detects light wavelengths that are located in the last 1/3 of the flame envelope is/are?

uv
visual
IR
A and C

Answer 10

IR

Question 11

Hot surfaces found in a firebox after the burner has been extinguished can be a problem for which type of visual flame scanner?

Uv
visual
IR
ALL

Answer 11

IR

Question 12

Safety controls used on burners over 400 MBH are typically of the reset type.

Answer 12

manual

Question 13

What burner ignition device avoids wasting fuel for pilot flames and assemblies?

Answer 13

Direct spark igniter and Hot surface igniter

Question 14

Older hot surface ignitors were constructed of;

Answer 14

silicon Carbide

Question 15

A spark igniter must be driven by sufficient power that will jump an air gap of to its receiving electrode.

Answer 15

1/8”

Question 16

Hot surface igniters are most susceptible to damage;

Answer 16

During transportation

Question 17

Pilot flames are generally considered to be;

Answer 17

Non-aerated

Question 18

Hot surface igniters may be either 24 volts or 120 volts.

T or F

Answer 18

True

Question 19

Manufacturers suggest a spark ignition system are able to be modified for field alterations.

Answer 19

False

Question 20

A pilot flame must be capable of rapid burner ignition when the flame is _____________.

Answer 20

at its smallest size

Question 21

Which test is required on all pilot operated burners?

Answer 21

Turn-down test

Question 22

The acronym “ECO” represents;

Answer 22

energy cut off

Question 23

The ________________________ allows an ECO to replace the temperature relief portion of a temperature and pressure relief valve on a hot water storage tank.

Answer 23

National Plumbing Code of Canada

Question 24

The power unit in the fuel control valve must respond to flame failure within ___________ for continuous pilot operated systems installed on gas fired furnaces 400 MBH or less.

Answer 24

180 secs

Question 25

The power unit in the fuel control valve must respond to flame failure within ____________ for direct-spark or hot surface ignition systems installed on gas fired furnaces 400 MBH or less.

Answer 25

90 secs

Question 26

Ignition and flame proving components position is/are determined by the;

Answer 26

Manufacturer

Question 27

Placement of the flame rod is so that approximately one inch (25 mm) of the flame rod tip is enveloped in the outer cone of the burner flame with the rod placed at the of a bank of burners, away from the primary ignition device.

Answer 27

far end

Question 28

Oxide buildup can be removed from a flame rod by gently cleaning it with;

Answer 28

scotchbtite pad OR fine emery cloth

Question 29

If an igniter requires replacement, you should try to obtain the replacement part.

Answer 29

original equipment

Question 30

What term is used to describe ignition of several burners in sequence as the flame travels from one burner to the next when utilizing a hot surface igniter to light the main burners?

Answer 30

Crossover

Question 31

Before you attempt any repair or trouble-shooting on a gas-fire appliance you should familiarize yourself with;

Answer 31

Manufacturers instructions AND sequence of operations

Question 32

With regards to the normal operating sequence of a HSI mid-efficient furnace, what would be the next occurrence after the air-proving switch has been activated?

Answer 32

Energize the hot surface igniter

Question 33

With regards to the normal operating sequence of a mid-efficient furnace, what should occur after the main burner fuel has been ignited?

Answer 33

Prove the flame THEN de-emergize the igniter

Question 34

With regards to the normal operating sequence of a mid-efficient furnace, what portion of the sequence timing can typically be altered?

Answer 34

circulating air fan delay

Question 35

If a heat demand is disrupted due to a main burner flame not igniting and the control tries for ignition for a second or third time, the control could be described as;

Answer 35

Recycling

Question 36

If a heat demand is disrupted due to a loss of flame signal during normal operation and the control immediately tries to re-light the burner, the control could be described as;

Answer 36

Retrying

Question 37

If a heat demand is disrupted due to a loss of flame signal during normal operation and the control immediately locks out, the control could be described as;

Answer 37

Non-retrying

Question 38

Furnaces are fabricated to the requirements set out in the current;

Answer 38

CAN/CSA 2.3

Question 39

When you consider code requirements for operating controls of gas appliances, there are basic set/s of documents.

Answer 39

3