10 seconds after pilot extinguishes
47 seconds after pre-purge
44 seconds after FD fan starts
75 seconds after FD fan starts
60 seconds after FD fan starts
Number of cams and switches
A nozzle and vane assembly
Prior to pre-purging.
Immediately after completion of the pilot flame trial.
After pre-purging and just prior to pilot ignition.
After the automatic main burner fuel valve opens.
At the same time as the automatic main burner fuel valve.
Is one that has been extinguished by an inadequate flame signal.
Ignites, is proven stable and extinguishes after the main flame is established.
Burns continuously, like that in a home furnace.
Ignites before the main burner ignites, and is extinguished when the main burner is extinguished.
Must be manually ignited.
Operation control switch contacts close.
The main flame trial ends.
Flame failure switch contacts open.
The timer motor stops.
A post-purge begins.
Ends the ignition trial
Energizes the ignition transformer
Closes the pilot valve
Opens the main fuel valve
High steam pressure limit switch tripped.
Pilot flame trial failure.
Main flame trial failure.
An interlock, such as the combustion air proving switch, has failed.
Igniter transformer failure.
After the main burner flame ignites.
If the trial for ignition period has lasted approximately 15 to 30 seconds.
After the flame relay de-energizes.
Within 4 or 5 seconds.
Must be closed before pilot ignition.
Can be opened before the flame scanner sees a flame.
Can be opened any time during the start-up sequence.
Should be opened as soon as the pilot valve opens.
Must be opened before the ignition transformer energizes.
So that the programmer has time to verify permissiveness.
So that the operator has time to check the fuel and water systems.
So that combustibles are fully removed prior to ignition.
To cool the hot refractory.
So that combustion gases are fully removed prior to ignition.
Perform only a specific dedicated task.
Rapidly process large amounts of data.
Produce hypothetical solutions to problems.
Act as a networking switch.
Evaluate systems by comparison.
A laptop computer
A netbook computer
A mainframe computer
选择要在Apple App Store上查看的Topgrade应用程序。