Thomas & Betts UDAP Operating Gas Valve, Combustion Air Pressure Switch, Door Switch, Udas only

Page 33

FIGURE 22 - Venter Wheel Position on Shaft

5.Holding the venter motor, remove the three or four screws that attach the venter motor mounting plate to the venter housing. Remove the motor and wheel as- sembly from the heater.

6.Re-assemble with the replacement venter motor and wheel assembly. See FIG- URE 22.

7.Follow the wiring diagram to connect the venter wires.

8.Sizes 30 and 45 - Reconnect the gas supply at the union outside of the cabinet. Leak test the connection with leak detecting solution.

9.Replace the access panel. Restore power to the heater and turn on the gas. Light, following the instructions on the lighting instruction plate. Check for proper operation.

Venter Wheel,

 

Venter Motor Plate

 

Sizes 30-75

 

Fan

Motor Mounting

Bracket

Motor Sizes 30-75

Venter Wheel, Sizes 100-175*

Venter Motor Plate

Fan

Motor Mounting Bracket

Motor Sizes 100-400

*Venter wheel has different appearance on Sizes 200-400. Motor spacing is the same.

5/16” (8mm) inside

5/16” (8mm) inside

32.Operating Gas Valve

The gas valve requires no field maintenance except careful removal of external dirt accumulation and checking of wiring connections. Instructions for testing pressure settings re in Paragraph 12.

WARNING: The operating valve is the prime safety shutoff. All gas supply lines must be free of dirt or scale before connecting to the unit to ensure positive closure. See Hazard Levels, page 2.

Single

Optional

Stage

Two

Gas

Stage

Valve

Gas

 

Valve

33.Combustion Air Pressure Switch

See FIGURE 18, page 31, for location. If it is determined that the pressure switch needs replacing, use only the factory-autho- rized replacement part that is designed for the model and size of heater being serviced.

NOTE: A unit operating above 6000 ft elevation requires a high altitude pressure switch. See Paragraph 7.

34. Limit Control

If it is determined that the limit control needs replacing, use only a factory-authorized replacement part that is designed for the size of heater.

For approximate limit location, see FIGURE 18, page 31.

35. Door Switch

If it is determined that the door switch needs replacing, use only

a factory-authorized replacement part that is designed for the

- UDAS only

heater.

 

For approximate switch location, see FIGURE 18, page 31.

 

 

36. Transformer

See FIGURE 18, page 31, for location. Use a voltmeter to verify

that there are 24 volts output from the transformer. If the trans-

 

former is not functioning, it must be replaced. Use a replacement

 

transformer identical to the factory-installed model.

Form RZ-NA I-UDA, Mfg #195673 Rev 5, Page 33

Page 32 Page 34
Image 33
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Contents Series Fan-Type Unit Heaters Table of ContentsGeneral Installation CodesHazard Levels of Warnings in this Manual Venting Manual by ModelMassachusetts Requirement Warranty Uncrating and PreparationSize DimensionsModel Udas Separated Combustion Fan Size 100 125 Technical DataPressure Switch Instructions for Changing Pressure SwitchHigh Altitude Operation ClearancesModel Udap and Model UDAP-CV Combustion Air applies to Model Udap and ModelUnit Heater Location Heater ThrowLocation Recommendations Hanging the Heater Unit Heater Location cont’dModel Udap Size 100 125 150 175 225 250 300 350 400 Model Udas Size 100 125 150 175 225 250 300 350 400Recommended maximum hanger rod length is 6 feet 1.8M Connectors areBe sure Threaded swivel Locked toGas Piping and Pressures Sizing Gas Supply LineGas Connection Size Instructions Gas Piping and Pressures cont’d Manifold Pressure Settings by Altitude for CanadaInstructions for High Altitude Derate Two -Stage ValveFeet Meters High Altitude Capacity ChangesThermostat and Connections Burner Electrical Supply and ConnectionsCombustion Air Proving Switch Pressure Switch Pressure Switch Settings Combustion Air ProvingLimit Control Dip Switch Door Switch Model Udas only Ignition SystemNormal Heat Cycle Operating Sequence StatusLED LightsSW1 SW2 Time Ignition System cont’dContinuous Fan Operation Fault Modes Gas Valve Fan Motor Fault Modes cont’d LockoutOperating Sequence Wiring DiagramsWiring Diagrams cont’d SW1 Check Installation and Startup Check the installation prior to startup Heater StartupOperating Instructions Operating Sequence Vent System Testing Procedure Model Udap Check installation after startupMaintenance Schedule Startup cont’dUse only factory-authorized parts Burner Removal Instructions Refer to Figure Heat Exchanger Maintenance Burner MaintenanceInspect and Clean the Burner Re-Install the Burner Burner Maintenance cont’dInstructions to Re-Install the Burner Refer to Figure Burner OrificeDSI System IgnitionCont’d Fan BladesDoor Switch Combustion Air Pressure SwitchOperating Gas Valve Udas onlySwitch Flame Rollout Switch Sizes 30-125 onlyAir System Troubleshooting DisconnectVenter motor General TroubleshootingWill not start Burner willCont’d Troubleshooting cont’d

UDAP, UDAS specifications

Thomas & Betts is a well-respected name in the electrical and industrial products sector, known for its innovation and quality. Among its impressive portfolio, the UDAS and UDAP series of connectors stand out for their reliable performance and advanced features. These connectors are specifically designed to meet the rigorous demands of electrical applications in various industries.

The UDAS (Universal Disconnect Appliance Switch) and UDAP (Universal Disconnect Appliance Plug) are engineered for high-capacity applications where safety, efficiency, and ease of use are paramount. One of the main features of these connectors is their ability to deliver increased electrical resistance and durability. They are constructed from high-quality materials that can withstand extreme environmental conditions, making them ideal for outdoor and harsh industrial applications.

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Furthermore, these connectors are versatile, compatible with a wide range of electrical systems, and can be employed in applications such as HVAC, lighting, and power distribution. They also come in various sizes and configurations to accommodate diverse specifications, improving customization options for different projects.

In summary, the Thomas & Betts UDAS and UDAP series stands out for their robust design, quick-connect technology, and versatility across various industrial applications. Their durability and compliance with safety standards make them an excellent choice for professionals seeking reliable connectivity solutions in demanding environments. Investing in these connectors ensures optimal performance and safety in electrical installations, showcasing Thomas & Betts' commitment to excellence in electrical components.
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