Nu-Way MGN 2800N Installation & Maintenance Manual

Nu-Way MGN 2800N Installation & Maintenance Manual Manual pdf 21 page image

MGN 2800N HP 20High Gas Pressure Switch SettingWhen the burner is finally commissioned the gas switch must be adjusted with the burner running.Remove the cover, and move the dial in an anticlockwise direction until the switch trips and thepressure switch indicating light is illuminated (the burner will shut down). Move the pressure switchdial in a clockwise direction one division, fit the cover, and reset the pressure switch via the buttonsituated on the pressure switch cover. The burner will now restart.Low Gas Pressure Switch SettingThe low gas pressure switch is wired in series with the appliance controlling instruments and willcause the burner to effect a ‘safety shutdown’ if a loss in inlet gas pressure is detected.Isolate the burner and remove the gas pressure switch cover. Switch on the electrical supply andallow the burner to establish main flame. Slowly turn the adjustment dial on the gas pressure switchclockwise until the flame is extinguished and the burner shuts down. Turn the dial slowlyanticlockwise one division at a time until the burner restarts and establishes main flame. Re-checkthe performance and then turn the dial a further two divisions anticlockwise. Switch off the burnerand replace the gas pressure switch cover.FINAL CHECKCheck that all covers to components have been replaced and that locking devices are properlysecured. Check that the appliance control instruments are set to safe limits.Commissioning is now CompleteSwitch on the electrical supply.The burner will now operate until switched off:a. by controlling instruments of the applianceb. manuallyc. by power failure. On restoration of power, the burner will restart automatically and followsequence.RWF 40 MODULATING CONTROLBasic DisplayThe diagram opposite shows the RWF40 after switching on the supply voltage. This condition iscalled the basic display. The actual operating value and the currently active set-point will be shown.Manual operation, self-optimisation, the operating parameter and the configuration levels can beactivated from this display.To change the working set pointThe basic display shows the actual pressure/temperature of the boiler in red and the required setpoint pressure/temperature beneath in smaller green digits.One quick press of the PGM button, the display changes to show the set point as the larger red digitsand the SPI in the lower small green digits.Alter the red display using the up/down buttons to show the new required set point, press exit or letthe unit time out to return to the basic display which should be the new set point figure.To enter a new parameterThe parameters dictate the way in which the burner firing rate alters in response to changes in thepressure/temperature of the boiler.A major factor that determines the need to change the parameters is if the burner is fitted to a steamor hot water boiler. The table below indicates the parameter and its setting for steam and hot waterboilers. it must be emphasised that it is only an indication and any departure from these settingsshould be made in small increments, with time given to see how the burner is reacting to the changedparameter.