Roberts Gorden UHA[X][S] 45 Automatic Burner Control Sequence, Gas Valve for Models UHAXS 30

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UHA LOW PROFILE UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

Figure 16: Automatic Burner Control Sequence

Thermostat 24 V

Flue Blower

Pressure P

Switch C

Ignition Spark Start Gas ValveFlame Signal

Axial Fan

Burner Sequence for Ignition Control

START

RUN

SHUT DOWN

30 Seconds Purge*	30 Seconds Post Purge
NO
NC
ts = 10 Seconds
30 Seconds Delay	90 Seconds Delay

*Purge time begins at pressure switch change over.

Required Incoming Signals

If at any stage the flame fails, the control will retry

Signals Output By Control

for ignition. The control has four trials for ignition

before a one hour lockout.

Figure 17: Gas Valve for Models UHA[X][S] 30 - 45

Pressure Regulator

Gas Outlet

Outlet Pressure

Description		Part Number
Gas Valve 30 - 45	NG	90034500
Gas Valve 30 - 45	LP	90034600

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Contents Installation, Operation & Service Manual CombatUHA-Series Tubular Unit Heaters Low Profile Range Models UHAXS 30, 45, 60, 75, 100,Page TABLE OF CONTENTS 2008 Roberts-GordonLLCPrinted in U.S.A Page TABLE OF FIGURES Page SECTION 1: HEATER SAFETY 1.1 Manpower Requirements1.2 Safety Labels and Their Placement Figure 1: UHA 30 - 45 Label Placement For separated combustion units onlyFigure 2: UHA 60 - 75 Label Placement For separated combustion units onlyFigure 3: UHA 100 - 125 Label Placement For separated combustion units onlySECTION 2: INSTALLER RESPONSIBILITY 2.1 Wall Tag2.2 Corrosive Chemicals 2.3 National Standards and Applicable Codes3.4 Minimum Required Installation Clearances 3.2 Manufactured Units3.5 Clearances to Combustibles 3.6 Ventilation3.7 Gas Supply 3.8 Electrical Supply3.9 Vent 4.1 Gas Codes 4.2 Aircraft Hangars4.3 Parking Structures and Repair Garages 4.4 Electrical4.6 High Altitude SECTION 5: MAJOR COMPONENTS 5.1 General 5.2 Shelf Mounting and Suspension5.3 Wall Mounting Crush Hazard Use 3/8 threaded rod minimumFigure 5: Suspension Methods Figure 6: Shelf-MountingMethodsExisting cabinet screws must be re-used Description Part NumberWall Shelf Mounting Bracket Kit DescriptionFigure 8: Vertical Louvers Optional Push inlouver and compress spring to remove6.3 Vent Installation SECTION 6 VENTING6.1 Changing Vent and Air Intake Orientation 6.2 Venting6.3.1Standard Vented Heaters Models UHAX 30 - 6.4 Unvented Operation6.5 Horizontal Venting 6.6 Vertical Venting 6.7 Length Requirements6.7.1 Maximum Vent Lengths 6.8 Vent MaterialFigure 9: Vent and Roof Detail VerticalHorizontal OptionPage Figure 13: Concentric Vent Box Vertical OptionHorizontal OptionVent Terminal 7.1 Separated Combustion Installation 7.2 Unvented InstallationSECTION 7 AIR SUPPLY 7.3 Building VentilationSECTION 8: GAS PIPING 8.1 ConnectionsFigure 15: Gas Connection SECTION 9: WIRING 9.1 Positioning Thermostats9.1.1 Fan Control 9.2 Low Voltage Thermostat with One HeaterModel Relay TypeRelay Part Number UHAXS 30 -UHAXS 60 - DPST90436300 Max. Number of Heaters9.5 Internal Wiring Diagram 9.6 Ladder Wiring Diagram 9.7 Electrical Connection to the Heater SECTION 10: OPERATION AND MAINTENANCE 10.1 Pre-Start-UpChecks10.1.1 Louvers 10.1.2 Electrical ChecksFigure 16: Automatic Burner Control Sequence Figure 17: Gas Valve for Models UHAXS 30 -Required Incoming Signals Signals Output By Control10.2.3 Pressure Switch Figure 18: Gas Valve for Models UHAXS 60 -Check Gas Rate 10.2.4 Turning Off the Heater10.2.5 External Controls 10.3 Complete Start-Up10.3.1 Instruction to the User Reset Limit Switch - See Page 33, Section Figure 19: Manual Reset Limit SwitchSECTION 11: USER INSTRUCTIONS 11.1 User Instructions11.5 Simple Troubleshooting 11.5.1 Simple Troubleshooting Burner FaultsFigure 20: LED Diagnostic Codes 11.4.2 To Turn the Heater Off12.2 Burner Maintenance 12.3 Fan/Motor Assembly Maintenance12.4 Heat Exchanger Maintenance 12.5 Gas Valve Maintenance12.8 Maintenance Checklist 12.7 Venting and Air Intake PipeThe Vicinity of the Heater See Page 6, Sectionwhen installed Combustion Air IntakePipe Heat ExchangerSECTION 13: TROUBLESHOOTING 13.1 General STARTSECTION 13: TROUBLESHOOTING 13.3 Troubleshooting for Flame Supervision System 13.4Troubleshooting for Gas Valves 13.5Troubleshooting for Flue BlowerCorrect power STARTSECTION 14 REPLACEMENT PARTS Burner Components14.1 Gas Valve 14.2 Burner Compartment 14.2.1 Burner Injectors14.3 Ignition Electrode and Flame Probe 14.4 Heat Exchanger 14.5 Louver and Louver SpringsInstall Vertical screws Horizontal14.6 Flue Blower Vertical Installation 14.7 Pressure Switch 14.9 Axial Fan/Guard/Motor Assembly14.8 Ignition Control 14.9.1 Fan Removal and Replacement 14.9.2 To Replace the Fan Assembly14.10 Limit Switches 14.10.1 Removal and ReplacementSECTION 15: SPECIFICATIONS 15.1 Dimension Data TOP VIEWSIDE VIEW REAR VIEW15.2 General Technical Data Table All Models 15.3 Technical Data Table All ModelsWARRANTY IS VOID IF ROBERTS GORDON WILL PAY FORROBERTS GORDON WILL NOT PAY FOR Roberts-GordonPage OWNER WARRANTY REGISTRATION CARD About the InstallerPurchased From if different than installer Type of Installation check onePage Page Installation Clearances Fire Hazardclose to heater injury or property damage