104662B HONEYWELL | Alldatasheet
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104662B,D LEAD SULFIDE CELL APPLICATION The 104662 Lead Sulfide Cell plugs into a C7015A Infrared Flame Detector mount. The flame detecting unit is for use with an R7248, R7254, or R7258 infrared amplifier in an appropriate flame safeguard control. Cell sensitivities allow selecting a flame detecting unit for specific installa- tions. Remove the C7015A detector mount from the sighting pipe (Fig. 1). Be careful not to disturb the alignment of the pipe. Remove the old cell and replace with the new 104662 cell. Clean thedetector mount and any lens, orifice, or seal- off adapters (see Fig. 2). Screw the C7015A onto the sighting pipe, using care not to disturbthe pipe adjustment. CELL RANGES: 104662B Lead Sulfide Cell-yellow; normal sensitivity range. 104662D Lead Sulfide Cell-range; highest sensitivity range. INSTALLATION CHECKOUT L C7015A DETECTOR MOUNT LEAD SULFIDE CEL Fig. l-installing cell in C7015A mount. READ THIS SECTION COMPLETELY BEFORE PER- FORMING ANY TESTS. The operation of the flame detector depends on the amount of energy reaching it from the flame. The amount of flame energy depends on the fuel and combustion characteristics. Therefore, two installations which are identical at the factory may operate differently after they have been installed. Thorough testing of each installation determines whether adjustments are necessary. Call performance can be affected by: l. position, size, and burning characteristics of the flame, which depend o n degree of premix and temperature variations in the combustion chamber. 2. variable firing rates. 3. hot refractory background radiation. 4. ambient temperature. (Maximum allowable is 125” F [52’ C] at the cell). Actual operation is the only means of measuring cell performance, checking the effects of hot refractory radia- tion, and checking the effect of combustion chamber temperature on flame burning characteristics. Before beginning tests, check that: 1. the burner system has been properly adjusted. 2. the fuel lines have been purged of air. SEAL OFF 314 INCH ADAPTER HEAT [60 MM1 DRILL AND TAP
4 HOLE S 5,16 INCH (8MM]
DIAMETER, 4-l/4 INCH [IOS MM, BOLT CIRCLE 118387A SWIVEL MOUNT n1 IF 105172A SEAL OFF ADAPTER IS USED, 105061 “EAT BLOCK MUST ALSO BE USED TO PROVIDE CLEARANCE FO R C7015 LENS. 105134 = .I25 ,NCH 6926A 2 USE HEX WRENCH TO SCREW ORIFICE INT O 3,4 INCH COUPLING. Fig. 2- C7015A Infrared Flame Detector and accessory installation. F.P. Form Number 60-0471-l Rev. 6-89 0 Honeywell Inc. 1989
- the combustion chamber and flues are clear of un- burned fuel and fuel vapor. CELL PERFORMANCE TESTS Cell performance is measured by 3 tests-a Pilot Turndown Test, a Flame Signal Measurement Test, and a Hot Refractory Hold-in Test. l. The Pilot Turndown Test ensures that the main burner can be lighted by the smallest pilot flame that will hold in the flame relay. 2. The Flame Signa l Measurement Test check s that the flame signal is strong enough to provide reliable flame detection. (The ambient temperature of the cell during burner operation can also be checked during this test.) 3. The Hot Refractory Hold-in Test checks for delayed flame relay dropout caused by response of the detector to refractory radiation following a flameout. PILOT TURNDOWN TEST This test involves closing the main valve and reducing the pilot flame until it is just able to hold in the flame relay. Then the main valve is opened to verify a smooth burner lightoff. The exact procedure varies with the flame safe- guard control used. Refer to the instructions wit h the flame safeguard control for test procedures. FLAME SIGNAL MEASUREMENT TEST The minimum acceptable flame signal depends on the model of flame signal amplifier. Refer to the instructions with the flame safeguard control for signal strength and details of test meter hookup. The signal must be measured with a Honeywel l W136A Test Meter, or equivalent, plugged into the flame signal meter jack on the plug-in amplifier or on the flame safeguard control. Check the flame signal during lightoff, during the main burner firing cycle, and at all firing rates. The signal must be steady. If the flame detector is installed correctly and positioned to sense the flame properly, the minimum acceptable signal or a stronger signal should easily be obtained. The minimum acceptable flame signals are dependent upon the special flame safeguard control and its associated amplifier. For flame signal information, refer to the C7015A instruction sheet, form no. 60-2306. A less than minimum signal or an unsteady signal indicates a marginal installation or some defect in the circuit. Make sure that the detector lens, filter, and seal-off adapter are clean. Then check the sighting. Refer to the instructions with the flame safeguard control for trou- bleshooting the circuits. Any of theseconditions must becorrected. An unsteady signal usually indicates that the detector is viewing an unstable part of the flame. If the flame signal falls off as the combustion chamber heats up, the flame detector is view- ing hot refractory radiation that is overriding the flame signal. Refer to th e C7015A instruction sheet, form 60- 2306, for adjusting the sighting pipe and detector mount. A more sensitive cell range may be needed to correct mar- ginal or unsteady flame signals not caused by combustion chamber temperature or sighting problems. HOT REFRACTORY HOLD-IN TEST Test to make certain that hot refractory will not cause the flame relay 2K (in the flame safeguard control) to stay pulled-in after the burner flame goes out. This condition would delay response to flame failure and also would prevent a system restart as long as hot refractory is detected. First check the plug-inflame signal amplifier by initiating a burner cycle. When the programmer stops in the “run” position, terminate the firing cycle while the refractory is at a low temperature. Measure the time it takes for the flame relay 2K to drop out after the flame goes out. (Watch or listen to the flame relay to determine when it drops out.) If the flame relay fails to drop out within 4 seconds, open the master switch and replace the amplifier. Infrared (lead sulfide) detectors can respond to infrared rays emitted by a hot refractory, even when the refractory has visibly ceased to glow. Infrared radiation from a hot refractory is steady, whereas radiation from a flame has a flickering characteristic. The infrared detection system responds only to aflickering infrared radiation; it can reject a steady signal from hot refractory. However, the refractory’s steady signal can be made to fluctuate if it is reflected, bent, or blocked by smoke or fuel mist within the combustion chamber. Care must be taken when applying an infrared system to ensure its response to flame only. Tochecka C7015A lnfrared (lead sulfide) Flame Detec- tor for hot refractory hold-in, operate the burner until the refractory reaches its maximum temperature. If the instal- lation has a multifuel burner, burn the fuel most likely to reflect, bend, or obscure the hot refractory’s steady infra- red radiation. (Burn solids instead of liquids, or liquids instead of gases.) When the maximum refractory tempera- ture is reached, clos e all manual fuel shutoff valves, or open the electrical circuits o f a// automatic fuel valves. Visually observe when the burnerflamegoes out. After the flame goes out, measure the time it takes for the flame relay 2K to drop out. (Watch or listen to the flame relay to determine when it drops out.) If the flam e relay fails to drop out within 4 seconds, the infrared detector is sensing hot refractory. Immediately terminate the firing cycle. (Lower the set point of the burnercontroller, or set the fuel selector switch to OFF. Do not open the master switch.) NOTE: Some burners continue to purge their oil lines between the valve(s) and nozzle(s) even though the fuel valve(s) is closed. Termination of the firing cycle (instead of opening the master switch) will allow purging of the combustion chamber. This will reduce a buildup of fuel vapors in the combustion chamber caused by oil line purging. If the detector is sensing ho t refractory, the condition must be corrected. Add an orifice plate ahead of the cell to restricttheviewingareaofthedetector. Ifthisdoesn’t work, resight the detector at a cooler, more distant part of the combustion chamber. While resighting the detector, keep in mind that it must also sight the flame properly. You can also try lengthening the sighting pipe or decreasing the pipe size (diameter). Refertothe Installation Section of the C7015A instruction sheet, form number 60-2306, for de- tailed instructions. Continue adjustments until hot refrac- tory hold-in is eliminated.Honeywell inc. I International Sales Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, Golden Valley, MN 55422-4386 PRINTED IN U.S.A.