North American Evenglow 4723 Burner Control System & Installation Instructions
Sheet 4723-3
to other burners
Figure 1. Suggested Control System
trans.
GAS
8697
gas cock
7218 or 7216
built-in gas adjusting valve
4723- -E Burner
AIR
1122
to other burners
A. SYSTEM DESIGN
1. Use direct spark ignition whenever possible. Direct spark sys- tems are simpler to install and operate than pilots. Constant pilots on hot air systems are not recommended. 2. Make certain that burner is at low before lighting. The spark must be turned on before or at the same time as the gas. 3. Use constant spark for ignition, a distributor will not work for direct spark ignition (4723- -E). Either constant spark or distributor can be used with premix gas pilot (4723- -G). 4. Do not "cross zones" with one mixer for several pilot tips. Use at least one pilot mixer per zone. 5. If air pressure is greater than 8 osi, use a regulator in the pilot air line to maintain air pressure to the mixer. Do not depend on setting the manual air valve to reduce the air pressure. 6. Always cross-connect individual pilot gas regulators (to pilot air if gas pressure permits; otherwise to pilot mixture pres- sure). 7. Provide main air and gas metering orifices if it will not be pos- sible to obtain reliable flue gas analysis for setting ratio. 8. Do not use one regulator for burners at different levels on a furnace. The difference in gas pressure due to the "head" of gas affects the low fire setting and may cause rough lighting, overheating, or sooting.
9. When sizing the burner for use with the specific air tempera- tures, make the usual correction in air capacity per the for- mula on page 147, North American Combustion Handbook, Second Edition or Third Edition, Vol. I. 10. The gas adjustment cartridge furnished with standard cold air burners is omitted on hot air burners (4723-_-_/H). A conventional 1807 Valve must be used, piped as close to the burner as is practical. (Priced separately.) 11. It is prudent to calculate burner input at 10% XSAir when burning natural gas. 12. When burning propane, use full primary air and set slightly leaner. 13. The following options all reduce UV signal strength: Long flame holder "L" dimensions, firing vertically downward, the UV "Y" adapter, the optional air jet tube. 14. Slow speed electric control motors provide the smoothest control especially with the long "L" flame retainers. Pilots on burners with the long "L" flame holders can be "knocked out" if the main air valve actuates too quickly. Burners with standard "L" length flame retainers can be controlled with faster acting air valves like the 7216 regulator with the by- pass option, which allows low fire to be set and maintained much more accurately.
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