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12 Cards in this Set
- Front
- Back
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Automatic boiler programming controls
a) must incorporate a modulating control system b) do not require interlocking devices c) require an ON-OFF or two-position control switch d) cannot make use of high-low fire control e) are not interconnected with the water level control system |
C
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An interrupted pilot of an automatic boiler a) burns continuously, like that in a home furnace b) lights before the main burner and goes out with it c) is one which has been extinguished by a flame scanner d) lights, completes a trial, and extinguishes after a main flame trial e) must be manually ignited |
D
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The function of a programming control is a) to supervise feedwater supply to the boiler b) to regulate the fuel supply to the burner c) to regulate combustion controls during start-up d) control the boiler blowdown rate e) to regulate fuel, air, and water supply to the boiler |
C
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Boiler furnaces are purged a) so that the programmer has time to verify permissiveness of interlocks b) in order to ensure combustion gases are fully removed prior to ignition c) while the operator is given the opportunity to check fuel and water systems d) so that combustibles are fully removed prior to ignition e) to cool any glowing refractory |
D
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Automatic boiler liquid fuel manual valves should be opened a) prior to pre-purging b) after pre-purge and just prior to pilot ignition c) immediately after completion of the pilot flame trial d) after the automatic main burner fuel valve opens e) with the automatic main burner fuel valve |
A
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The operating pressure control will control the a) steam pressure in the boiler b) gas pressure to the burner c) water pressure to the boiler d) boiler furnace pressure e) steam pressure in the steam header |
A
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The second from last step in an automatic boiler programmed shutdown sequence is a) timer shutdown b) main flame trial c) post purge d) operating control switch contacts closing e) flame failure switch contacts opening |
C
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With automatic fuel fired boiler programmed control the normal firing period begins approximately a) 44 seconds after FD fan starts b) 75 seconds after FD fan starts c) 60 seconds after FD fan starts d) 10 seconds after pilot extinguishes e) 47 seconds after pre-purge |
C
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On a gas fired automatic boiler a normal programmed start-up takes approximately a) 105 seconds b) 55 seconds c) 27 - 40 seconds d) 120 seconds e) 70 seconds |
A
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During a programmed start-up if an ignitor spark is visible but no flame appears the operator should suspect a) a boiler low water level b) the main burner manual fuel valve is closed c) the pilot manual fuel valve is closed d) the scanner lead sulphide cell is weak e) the boiler steam pressure operating control switch is open |
C
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If a shutdown occurs during normal firing of a boiler and the steam pressure is below the normal cut-out value, the problem could be a) the sensing line to the combustion air proving switch has broken b) main flame trial failure c) pilot flame trial failure d) ignitor transformer failure e) high steam pressure limit switch tripped |
A
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On a boiler with high-low fire control, if the damper positioning switch is in the wrong position a) the damper motor may not operate b) a pre-purge will not occur c) a high fire main flame ignition could occur d) nothing will happen when the manual start switch is closed e) the pre-purge period will last indefinitely unless the problem is corrected |
A
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