750-297
Profire E/LNE Series Manual
3-5
Operation
2.
If a low water condition occurs, the burner shuts down as in Automatic Shutdown.
3.
If a high or low gas pressure condition occurs while firing on gas, the burner shuts down as in Automatic Shutdown.
A. Condition must be corrected and the respective gas pressure switch manually reset before the burner will fire
again on gas.
3.8 — Startup and Operating
3.8.1 — Gas Burners
1.
Close the main and pilot gas cocks.
2.
Make sure the ON-OFF switch is in the “OFF” position and the fuel selector switch is turned to “GAS.”
3.
Actuate the manual reset button of the flame safeguard control to close the safety switch contacts.
4.
Set the MANUAL-AUTO switch in the “MANUAL” position.
5.
Set the manual potentiometer in the low fire position.
6.
Open the gas pilot cock.
7.
Set the ON-OFF switch to “ON.” The burner will start and pre-purge. After pre-purge, the ignition transformer and
the gas pilot solenoid are energized. Before proceeding, conduct electrical interference and pilot turndown tests if
not previously done (see Section 3.2).
8.
On initial startup it is recommended that the main gas shutoff cock remains closed until the programmer has cycled
through pre-purge and pilot sequence. Then determine that the main gas valve opens. When this is confirmed, turn
the burner switch “OFF” and let the programmer finish its cycle.
9.
Check to see that the gas valve has closed tightly. If ignition does not occur, turn the burner switch “OFF” and allow
the programmer to recycle for a new ignition trial.
10.
Turn the burner “ON” and after pilot ignition when the flame relay pulls in, the slow opening, motorized, main gas
valve is energized. The main flame should ignite at this time. The gas valve and air damper continue advancing until
high fire is reached.
11.
Do not repeat unsuccessful light off attempts without rechecking burner and pilot adjustment. Vent fuel vapors from
the combustion chamber after each unsuccessful light off attempt.
12.
Set the gas low fire rate by adjusting the butterfly valve and air linkage.
13.
When low fire is adjusted, shut down the burner.
14.
Restart several times to be sure the low fire setting is suitable. Readjust if necessary. Never start the burner with fuel
vapor in the furnace. In case of an emergency, open the main power switches and close all fuel valves.
15.
After combustion adjustments are satisfactorily set, allow the heating vessel to slowly reach normal operating
pressure or temperature.
16.
Turn the potentiometer switch to the high fire position. Check high fire at this point using combustion instruments.
17.
Do not disturb established low fire adjustment. Allow the burner to return to low fire position before adjusting high
or intermediate settings.
High fire combustion analysis typically is 9% to 10.5% CO
2
. When conditions covered above are assured, refer to
Sections 3.9 and 3.10.