Roberts Gorden UHA[X][S] 75 Pressure Switch, Ignition Control, Axial Fan/Guard/Motor Assembly

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14.7 Pressure Switch

SECTION 14: REPLACEMENT PARTS

14.7 Pressure Switch

Pull off 3 way connector. Spring open plastic clips of mounting cradle. Replace with correct type of pressure switch for model. The pressure switches are color coded for each pressure setting. Carry out a start-up after working on or changing a pressure switch. See Page 29, Section 10.

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MODEL	UHA[X][S] 30	UHA[X][S] 45	UHA[X][S] 60	UHA[X][S] 75	UHA[X][S] 100	UHA[X][S] 125

Pressure Switch	90439801	90439810	90439802	90439810	90439810	90439803
Kit P/N	90439801	90439810	90439802	90439810	90439810	90439803

Color Code	pink	black	yellow	black	black	gray

Set Point in. wc	.23	.35	.32	.35	.35	.41

Pressure Switch	90439850	90439850	90439850	90439850	90439850	90439850
Snap Ring P/N	90439850	90439850	90439850	90439850	90439850	90439850

14.8 Ignition Control

The control mounts to the heat exchanger plate. Pull out ignition cable and wiring from board, noting their positions. Release the four mounting standoffs. Refit in reverse. Ensure correct location of ignition cable and all other wiring.

14.9 Axial Fan/Guard/Motor Assembly

The axial fan unit for the heater is supplied completely assembled and balanced.

MODEL	UHA[X][S] 30	UHA[X][S] 45	UHA[X][S] 60	UHA[X][S] 75	UHA[X][S] 100	UHA[X][S] 125

Axial Fan Guard	91901103	91901103	91901102	91901102	91901102	91901102

Axial Fan Motor	90600104	90600104	90600105	90600105	90600106	90600106

Axial Fan Blade	90709004	90709003	90709002	90709001	90709001	90709001

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Contents Combat Installation, Operation & Service ManualUHA-Series Tubular Unit Heaters Low Profile Range Models UHAXS 30, 45, 60, 75, 100,Page Printed in U.S.A TABLE OF CONTENTS2008 Roberts-GordonLLC Page TABLE OF FIGURES Page 1.2 Safety Labels and Their Placement SECTION 1: HEATER SAFETY1.1 Manpower Requirements For separated combustion units only Figure 1: UHA 30 - 45 Label PlacementFor separated combustion units only Figure 2: UHA 60 - 75 Label PlacementFor separated combustion units only Figure 3: UHA 100 - 125 Label Placement2.1 Wall Tag SECTION 2: INSTALLER RESPONSIBILITY2.2 Corrosive Chemicals 2.3 National Standards and Applicable Codes3.2 Manufactured Units 3.4 Minimum Required Installation Clearances3.5 Clearances to Combustibles 3.6 Ventilation3.9 Vent 3.7 Gas Supply3.8 Electrical Supply 4.2 Aircraft Hangars 4.1 Gas Codes4.3 Parking Structures and Repair Garages 4.4 Electrical4.6 High Altitude 5.2 Shelf Mounting and Suspension SECTION 5: MAJOR COMPONENTS 5.1 General5.3 Wall Mounting Crush Hazard Use 3/8 threaded rod minimumExisting cabinet screws must be re-used Figure 5: Suspension MethodsFigure 6: Shelf-MountingMethods Part Number DescriptionWall Shelf Mounting Bracket Kit DescriptionPush in Figure 8: Vertical Louvers Optionallouver and compress spring to removeSECTION 6 VENTING 6.3 Vent Installation6.1 Changing Vent and Air Intake Orientation 6.2 Venting6.5 Horizontal Venting 6.3.1Standard Vented Heaters Models UHAX 30 -6.4 Unvented Operation 6.7 Length Requirements 6.6 Vertical Venting6.7.1 Maximum Vent Lengths 6.8 Vent MaterialVertical Figure 9: Vent and Roof DetailHorizontal OptionPage Vertical Option Figure 13: Concentric Vent BoxHorizontal OptionVent Terminal 7.2 Unvented Installation 7.1 Separated Combustion InstallationSECTION 7 AIR SUPPLY 7.3 Building VentilationFigure 15: Gas Connection SECTION 8: GAS PIPING8.1 Connections 9.1 Positioning Thermostats SECTION 9: WIRING9.1.1 Fan Control 9.2 Low Voltage Thermostat with One HeaterRelay Type ModelRelay Part Number UHAXS 30 -DPST UHAXS 60 -90436300 Max. Number of Heaters9.5 Internal Wiring Diagram 9.6 Ladder Wiring Diagram 9.7 Electrical Connection to the Heater 10.1 Pre-Start-UpChecks SECTION 10: OPERATION AND MAINTENANCE10.1.1 Louvers 10.1.2 Electrical ChecksFigure 17: Gas Valve for Models UHAXS 30 - Figure 16: Automatic Burner Control SequenceRequired Incoming Signals Signals Output By ControlFigure 18: Gas Valve for Models UHAXS 60 - 10.2.3 Pressure SwitchCheck Gas Rate 10.2.4 Turning Off the Heater10.3.1 Instruction to the User 10.2.5 External Controls10.3 Complete Start-Up Figure 19: Manual Reset Limit Switch Reset Limit Switch - See Page 33, SectionSECTION 11: USER INSTRUCTIONS 11.1 User Instructions11.5.1 Simple Troubleshooting Burner Faults 11.5 Simple TroubleshootingFigure 20: LED Diagnostic Codes 11.4.2 To Turn the Heater Off12.3 Fan/Motor Assembly Maintenance 12.2 Burner Maintenance12.4 Heat Exchanger Maintenance 12.5 Gas Valve Maintenance12.7 Venting and Air Intake Pipe 12.8 Maintenance ChecklistThe Vicinity of the Heater See Page 6, SectionCombustion Air Intake when installedPipe Heat ExchangerSTART SECTION 13: TROUBLESHOOTING 13.1 GeneralSECTION 13: TROUBLESHOOTING 13.3 Troubleshooting for Flame Supervision System 13.5Troubleshooting for Flue Blower 13.4Troubleshooting for Gas ValvesCorrect power START14.1 Gas Valve SECTION 14 REPLACEMENT PARTSBurner Components 14.2.1 Burner Injectors 14.2 Burner Compartment14.3 Ignition Electrode and Flame Probe 14.5 Louver and Louver Springs 14.4 Heat ExchangerInstall Vertical screws Horizontal14.6 Flue Blower Vertical Installation 14.8 Ignition Control 14.7 Pressure Switch14.9 Axial Fan/Guard/Motor Assembly 14.9.2 To Replace the Fan Assembly 14.9.1 Fan Removal and Replacement14.10 Limit Switches 14.10.1 Removal and ReplacementTOP VIEW SECTION 15: SPECIFICATIONS 15.1 Dimension DataSIDE VIEW REAR VIEW15.3 Technical Data Table All Models 15.2 General Technical Data Table All ModelsROBERTS GORDON WILL PAY FOR WARRANTY IS VOID IFROBERTS GORDON WILL NOT PAY FOR Roberts-GordonPage About the Installer OWNER WARRANTY REGISTRATION CARDPurchased From if different than installer Type of Installation check onePage Page Fire Hazard Installation Clearancesclose to heater injury or property damage