CHAPTER 10 Flashcards
The programmed startup sequence of oil-fired boilers with no pilot light is as follows:
1. The flame detector senses the flame and causes the flame relay to close
2. The spark from the ignition transformer ignites the main burner
3. The load relay energizes the ignition transformer, fuel oil shut-off valve, and motor driving the air fan and fuel pump
4. The ignition transformer is then de-energized
5. The operating control closes a switch
Select one:
A.
5, 3, 2, 1, 4
B.
1, 2, 3, 4, 5
C.
3, 2, 1, 5, 4
D.
2, 5, 1, 4, 3
E.
4, 5, 2, 1, 3
A.
5, 3, 2, 1, 4
The switch in the operating control of a steam boiler is opened by:
A.
Falling water pressure
B.
Falling steam pressure
C.
Rising steam pressure
D.
Rising steam temperature
E.
Falling steam temperature
C.
Rising steam pressure
The switch in the operating control of a hot water boiler is opened by:
Select one:
A.
Rising water temperature
B.
Rising steam temperature
C.
Falling water pressure
D.
Rising water pressure
E.
Falling water temperature
A.
Rising water temperature
The two types of boiler combustion control include:
1. On-Off
2. Automatic
3. Modulating
4. Manual
Select one:
A.
3, 4
B.
2, 4
C.
1, 2
D.
1, 3
E.
2, 3
D.
1, 3
If the pilot burner fails to ignite, or if the pilot does go on, the gas burner fails to ignite a lockout switch will be energized after a short trial period of _____ seconds from the time of startup.
Select one:
A.
30 to 50
B.
10 to 20
C.
15 to 30
D.
5 to 10
E.
20 to 40
C.
15 to 30
What is the name given to the component that coordinates and sequences the boiler operation?
Select one:
A.
Plant controller
B.
Boiler master
C.
Programming controller
D.
Air/fuel ratio controller
E.
Header pressure controller
C.
Programming controller
If the blower starts but stops again after 5-10 seconds:
Select one:
A.
Replace motor
B.
Close the blower switch
C.
Refer to manufacturer’s manual
D.
Reset safety lock-out switch
E.
Check the low air pressure switch
E.
Check the low air pressure switch
The switch in the operating control of a steam boiler is closed by:
Select one:
A.
Falling water pressure
B.
Rising steam pressure
C.
Falling steam pressure
D.
Falling steam temperature
E.
Rising steam temperature
C.
Falling steam pressure
Before a steam or hot water boiler can be started by a programming control, all but one of the following conditions must be fulfilled:
Select one:
A.
The water in the boiler drum must be above the cut-off point of the low-water fuel cut-off
B.
All manually operated valves in the fuel lines to the pilot and main burner must be closed
C.
If the boiler is gas-fired, the fuel supply pressure to the burner valves must be above the cutout point of the low gas pressure cut-off
D.
The main power switch or breaker must be closed
E.
The steam pressure or water temperature must be at or below the cut-in setting of the operating control
B.
All manually operated valves in the fuel lines to the pilot and main burner must be closed
The switch in the operating control of a hot water boiler is closed by:
Select one:
A.
Falling water pressure
B.
Rising water pressure
C.
Falling water temperature
D.
Falling steam temperature
E.
Rising steam temperature
C.
Falling water temperature
If the burner fails to ignite during the ignition trial period, the lock-out switch is activated and the boiler cannot be restarted until:
Select one:
A.
A short time period has passed
B.
The furnace has been purged
C.
The fuel valve has been reset
D.
The switch has been manually reset
E.
The switch resets automatically
D.
The switch has been manually reset
Purging a furnace means forcing a flow of:
Select one:
A.
Air through a furnace for a set period of time when the burner is in operation.
B.
Fuel through a furnace for a set period of time when the burner is not in operation.
C.
Fuel through a furnace for a set period of time when the burner is in operation.
D.
Water through a furnace for a set period of time when the burner is in operation.
E.
Air through a furnace for a set period of time when the burner is not in operation.
E.
Air through a furnace for a set period of time when the burner is not in operation.
A programming control on a natural draft gas fires boiler operates in the following sequence.
1. The main burner is ignited
2. The flame detector senses the flame and causes the main gas valve to open
3. The ignition transformer and pilot gas valve are de-energized and closed, if an interrupted pilot is used
4. The operating control initiates a startup
5. The load relay energizes the ignition transformer and the pilot gas valve
Select one:
A.
3, 2, 1, 5, 4
B.
4, 5, 2, 1, 3
C.
5, 3, 2, 1, 4
D.
2, 5, 1, 4, 3
E.
1, 2, 3, 4, 5
B.
4, 5, 2, 1, 3
The lock-out switch will be actuated when the:
Select one:
A.
Power fails
B.
Operating control opens
C.
Flame scanner loses the flame
D.
Operating control closes
E.
Low water fuel cut-off opens
C.
Flame scanner loses the flame
Each time the boiler starts up it has to go through:
Select one:
A.
Standard fuel system safety checks
B.
Standard checks associated with a safe startup procedure.
C.
A water purge procedure
D.
Standard checks on the water quality
E.
A test of the combustion control
B.
Standard checks associated with a safe startup procedure.
