Nu-Way MGN 2800N Installation & Maintenance Manual

Nu-Way MGN 2800N Installation & Maintenance Manual Manual pdf 10 page image

MGN 2800N HP 9BURNER AIR CONTROLSThe air for combustion is controlled by an adjustable air flap located inside the air inlet on the righthand side of the burner viewed from the rear. Its purpose is to regulate and control the volume ofcombustion air flowing through the burner. Combustion air is controlled by a three position servomotor. Positions for high and low flame air are adjustable. A fully closed position is incorporated forwhen the appliance temperature/pressure is satisfied.Air DiffuserThe air diffuser is fitted to the front end of the inner assembly and located within the flame tube.Its function is to control the volume of combustion air and create a pressure drop over the burnerhead to ensure good fuel/air mixing and flame stability.Air Pressure SwitchThe air pressure switch is located on the right side of the burner casing viewed from the rear. It isrequired to prove adequate air flow throughout the burner operating cycle. Air flow failure at anystage will result in burner lockout.BURNER GAS CONTROLSGas NozzleThe gas nozzle is fitted to the front end of the inner assembly and located in the flame tube. Theholes in the gas nozzle are designed to suit the output of the particular burner model and gas typebeing used.High Gas Pressure SwitchA high gas pressure switch is fitted and pre-wired to the gas train to ensure that if the gas pressure atthe burner head increases above the gas pressure at maximum continuous running, then the burnerwill shut down to a safe condition, thus indicating a fault on the governing valve (air/gas ratio valve).The switch is factory set to the maximum position.Final adjustment of this switch is described in the Commissioning section on page 20.Low Gas Pressure SwitchThe low gas pressure switch is located on the inlet side of the gas valve block on the left ofthe burner, viewed from the rear. It is required to monitor inlet gas pressure during theburner operating cycle. Gas pressure failure will result in safe shutdown of the burner. Finaladjustment of this switch is described in the Commissioning section on page 20.Gas Valve TrainThe gas valve train system includes an air/gas ratio controller, safety shut-off valve, and gasregulator in the start rate line. Three impulse pipes are connected to the air/gas ratiocontroller. All are factory supplied. One pipe is connected to the burner hinged extensionand supplies combustion air pressure to the ratio controller. A second pipe is connecteddownstream of the valve set and supplies gas pressure to the ratio controller. The third pipeis vented to atmosphere. Valve adjustments are detailed in Valve Adjustment Diagram onpage 13.ELECTRICAL DATA3 Phase 400V 50HzBurnerModelMotor(kW / rpm)StartCurrent (A)Full LoadCurrent (A)Main Fuse(A)Cable Size(mm2)MGN 2800N HP 7.5 /2800 57 15.2 40 4.0