8
ALIGNMENT AND ADJUSTMENTS
Before installing or adjusting scanners, thoroughly plan the scanning objectives in reference to the
boiler/furnace mode of operation.
The following procedures are recommended to ensure optimum flame detection and discrimination.
Flame discrimination is the ability to see the flame of only one burner or one igniter with other burn-
ers or igniters operating nearby.
These procedures should be used whenever parts are replaced, when the scanner has been moved,
when the flame shape is altered (additional fuels, new burners, burner/register modifications) as well
as on all new installations. Signal readings referred to in this procedure are as displayed on a 0-3
VDC Fireye flame signal meter. (P/N 38-54, 38-55, 38-56, 38-62).
1, 2
Igniter Flame Scanner
1. Apply power to scanner and associated control.
2. Start Igniter.
3. Adjust scanner sighting to detect igniter flame in the manner shown in Figure 2.
4. When flame is properly sighted and the control sensitivity properly adjusted (see Caution below)
the signal meter should register between 4 and 16. If readings fluctuate widely, readjust scanner
sighting until highest steadiest reading is obtained.
5. When the proper signal reading has been obtained, make sure that the scanner and the associated
control do not respond to the ignition spark. This is accomplished by cutting off the fuel to the
igniter and attempting to start the igniter using the spark igniter. If the system responds to the
spark, the sighting should be realigned.
CAUTION: Do not increase sensitivity any more than necessary to provide proper detection
of the minimum igniter flame. Minimum igniter flame is the minimum flame required to
ignite the main burner reliably. Be sure to test for reliable signals under maximum air flow
conditions when the igniter flame may be deflected outside the line of sight. If this occurs,
resighting is required.
Main Flame Scanner
1. Apply power to scanner and control.
2. Start igniter.
3. Adjust scanner sighting so that ignition spark and igniter flame are not detected. Test should be
conducted with maximum igniter flame and with both minimum and maximum air flow.
Note: This step may not be practical with Class 1 igniters, but may be desirable with Class 3.
4. Start main burner.
5. Adjust scanner sighting to detect main burner flame. When sighting is correct (see Figure 4), the
signal should read between 4 and 32 on a Flame Signal Meter, Fireye P/N 38-54 or 38-55, with-
out extreme fluctuations in the signal reading.
6. When proper signal is established, manually close off the main burner fuel supply. When burner
flame becomes unstable or is extinguished, the associated Fireye control should register a “No
Flame” condition.
7. Start an adjacent burner and vary its firing rate under normal air flow conditions. Make certain
that the main flame scanner on the burner not in service does not respond to the adjacent burner.
1
If using analog bargraph meter (P/N 38-88), the flame will be properly sighted when there are 5-8 LEDs illuminated.
2
When used with the 25SU3-2000 series amplifiers and appropriate power supply, the required flame signal strength (in terms
of “pulses-per-second,” will be determined by the “Flame-On” and “Flame-Off” thresholds programmed into the amplifier.
Refer to bulletin CU-34 for additional information.
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