Manual 2100-587CPage 46 of 5935. LOW-NOX BURNER ASSEMBLY “N”SUFFIX MODELS ONLY – U.S.INSTALLATIONS ONLYNATURAL GAS MODELS ONLYModel numbers designated with an “N” are designedfor low NOx emissions which comply with allCalifornia Air Quality Management District regulationsfor nitrogen oxide emission levels. Refer to Figurebelow for NOx insert information.* * IMPORTANT * *For propane (LP) conversions the NOxreduction screen inserts shown below must beremoved. This is accomplished by removingthe burner box assembly and removing theNOx screens. Reassemble unit properlybefore firing. Failure to remove the NOxscreens can result in improper operation andmalfunction of the burner system.FIGURE 22LOW NOX INSERTR-410A34. REFRIGERANT CHARGEThis unit was charged at the factory with the quantity ofrefrigerant listed on the serial plate. AHRI capacity andefficiency ratings were determined by testing with thisrefrigerant charge quantity.The pressure tables (page 45) show nominal pressuresfor the units. Since many installation specific situationscan affect the pressure readings, this information shouldonly be used by certified technicians as a guide forevaluating proper system performance. They shall notbe used to adjust charge. If charge is in doubt, reclaim,evacuate and recharge the unit to the serial plate charge.