A.O. Smith 2600, 3400, 1700, 2000 instruction manual Burner Control System, Overview

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CONTROL SYSTEM

BURNER CONTROL SYSTEM

Figure 47.  R7910A1138 CONTROL SYSTEM

The R7910A1138 is a burner control system that provide heat control, flame supervision, circulation pump control, fan control, boiler control sequencing, and electric ignition function. It will also provide boiler status and error reporting. Multiple boilers can be joined together to heat a system instead of a single, larger burner or boiler. Using boilers in parallel is more efficient, costs less, reduces emissions, improves load control, and is more flexible than the traditional large boiler. Control System consists of:

R7910A1138 Control Device.

S7999B Touchscreen Display—required for setup and ModBus communication but not required for the system to operate once the R7910A1138 is programmed.

S7910A Local Keyboard Display Module.

Flame Rod .

Temperature Sensor, NTC Type 10KΩ at 77°F (25°C) or 12KΩ at 77°F (25°C).

Limit Sensor, NTC Type 10KΩ at 77°F (25°C).

24V Digital I/O.

OVERVIEW

Functions provided by the R7910A1138 include automatic boiler sequencing, flame supervision, system status indication, firing rate control, load control, CH/DHW control, limit control, system or self-diagnostics and troubleshooting.

The R7910 maximum version of the controller offers:

1.NTC-temperature sensor for:

Outlet Limit And Temperature.

Stack Temperature Limit and Temperature.

Inlet Temperature.

Outdoor Temperature (R7910 only).

2.Modulating output PWM-driven rotation speed controlled DC-fan for optimal modulation control.

3.Three Pump Outputs with 5 selectable operation modes.

4.24VAC:

Output control of gas valve (Pilot and Main) and External Ignition Transformer.

Digital inputs for room limit control, high limit control, Gas pressure switch, low water cutoff.

5.External spark transformer.

6.Flame Sensor.

7.Test jacks for flame signal measurement from either a flame rod or UV flame sensor.

8.Alarm Output.

Figure 48.  GENERAL R7910A1138 BOILER SCHEMATIC

The above figure shows two loops of heat control: Central Heating (CH), and an optional second loop for Domestic Hot Water (DHW) can be configured on each R7910A. The DHW loop transfers heat from the boiler outlet to hot water appliances in conjunction with the primary system heat loop. Priority assignment to each heat loop can be configured to specify which loop gets serviced first.

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Contents XP Boiler Table of Contents Safe INSTALLATION, USE and Service ApprovalsImportant Definitions General Safety Model Identification IntroductionAbbreviations Used QualificationsOperating Characteristics Dimensions and Capacity DataDouble Heat Exchanger Boiler Rough in Dimensions Double Electrical Requirements RatingsXB Models FLOW, Head and Temperature Rise FLOW, Head and Temperature RiseSingle Heat Exchanger Boiler Components Features and ComponentsDouble Heat Exchanger Boiler Components Low water cutoff board and sensor probe Lwco Component DescriptionControl Components Water Temperature Limit Controls Flame Sensor Water Temperature SensorsMain Power Supply Switch LOW Water Cutoff Device LwcoBoiler Installation Considerations GeneralHydronic System HOT Water Boiler System General Water Line Connections Internal ContaminantsClosed Water Systems Thermal ExpansionGAS Connections Explosion HazardGAS Supply Line Sizing Corrosive Materials and Contamination SourcesVAC Power Supply Wiring Field WiringPower Supply Check LOW Voltage Control WiringSuggested Pipe Size for Multiple GAS Appliances Natural GAS Required Ability General RequirementsLocation Replacing Existing Common Vented BoilerPanels and Covers Installation ClearancesChemical Vapor Corrosion LevelingConfined Space Outdoor AIR Through TWO Openings Fresh AIR Openings for Confined SpacesOutdoor AIR Through ONE Opening Outdoor AIR Through TWO Vertical Ducts Outdoor AIR Through TWO Horizontal DuctsAIR from Other Indoor Spaces DuctsVenting Vent and AIR Pipe Installation Requirements for Installation in CanadaAIR Inlet Pipe Materials Horizontal Installation Requirements Vertical Installation RequirementsDirect Vent Installation Requirements Venting SupportsModels Vent KIT Numbers XB/XW TEE Models Vent KIT Numbers XB/XW Rain CAPModels Vent AIR Intake XB/XW KIT Numbers Rain CAP Elbow Models Vent AIR Intake XB/XW KIT Numbers TEE ElbowDirect VENT, Vertical Vent Horizontal Intake Power Vent Termination Clearances Sidewall Power VentDirect Vent Termination Clearances Sidewall Direct VentBELOW. Keep Clear of ALL Obstructions Direct Vent Horizontal Termination VENT/AIR Termination LocationsTermination Prepare ROOF/WALL Penetrations Direct Venting Vertical TerminationVertical ClearancesModel Vent Diameter Vent MIN. Length Vent MAX. Length Inch Condensate Neutralizer Condensate DisposalCondensate Trap XP Models AO Smith Condensate Neutralizer KIT NumbersGAS Supply Connections GAS Supply Pipe ConnectionsGAS Pressure Requirements Purging GAS Line Pipe Sizes for Propane GASCheck GAS Supply Inlet Pressure Check for GAS LeaksFilling HOT Water Supply Boiler Installation Filling and Purging of Heating Boiler InstallationBoiler Start UP and Operations Manifold Pressure ConnectionsCHECK/CONTROL Water Hardness Freeze Protection Hydronic Heating InstallationINSPECT/FILL Condensate System Water Hardness Medium 0-12 Grains PER Gallon XW ModelLighting and Operating Instructions Setting of the Test Mode AdjustmentHigh Fire Rate Control System Burner Control SystemOverview Specifications Communications and DisplaysBurner Control Operation General Operational Sequence Lead LAG Domestic HOT WaterLead LAG LL Master General Operation Features Local Operator Interface Display SystemDefinitions Installation Instructions S7999B OI Display Quick Setup S7999B OI DisplayMounting the S7999B OI Display and Power Supply Common OI Display page Symbols POWER-UP ValidationStarting UP the S7999B OI Display NavigationS7999B Display page Flow Status or Home Configure ButtonLogin Configuration PasswordChange Parameter Settings KeyboardParameter Verify Example of Change ConfigurationFAULT/ALARM Handling Data CommentHistory Button Example of Hydronic History Operation Button Control Expanded Alert DetailSystem Configuration S7999B OI Display only Diagnostics ButtonConfiguration System Synchronization S7999B OI Display onlyHydronic Control Code Description Recommended Troubleshooting Lockout Codes TroubleshootingReserved ILK OFF Flame Operation Faults 105 Flame detected out of sequence Adjust the LF switch while in this position Inspect the Combustion Pressure Switch to make Code Description Recommended Troubleshooting Lockout Codes Code Description Recommended Troubleshooting Lockout Codes Allowed Code DescriptionFan Parameter Errors Code Description Steam 20mA water temperature setting was invalid Abnormal Recycle Hardware flame bias delta high Eeprom DHW Plate Heat Exchanger Errors Maintenance Schedules Maintenance ProceduresGeneral Maintenance Inspect Boiler AreaBurner Maintenance Blower CompartmentAIR Filter BOX Venting Maintenance Heat Exchanger MaintenanceCondensate Removal System Handling Ceramic Fiber Materials Replacement PartsInlet DIA Piping DiagramsStorage Tank AOS Conditions and Exceptions Limited Warranty

3400, 1700, 2000, 2600 specifications

A.O. Smith, a leader in water heating solutions, has developed a range of high-efficiency water heaters that cater to various residential and commercial needs. Among their stellar offerings are the A.O. Smith 2600, 2000, 1700, and 3400 models, each boasting impressive features, cutting-edge technologies, and excellent energy efficiency.

The A.O. Smith 2600 model is designed for those who require a robust water heating solution with a capacity to handle high-demand scenarios. It utilizes a highly efficient heating element that provides rapid heating and maintains a steady output. The built-in smart control system allows users to monitor temperature settings and track energy consumption, ensuring optimal performance.

Next in line, the A.O. Smith 2000 is perfect for households that require a reliable and efficient water heater without compromising on space. This compact model integrates advanced thermal insulation that minimizes heat loss, coupled with a powerful heating element that ensures quick heating times. Its sleek design makes it suitable for various installations while maintaining aesthetic appeal.

The A.O. Smith 1700 model caters specifically to smaller residential needs but retains features that align with higher-end models. It incorporates state-of-the-art safety features, including overheat protection and a pressure relief valve. Its lightweight structure and ease of installation stand out, making it a recommended choice for those looking for efficient heating without extensive modifications to their plumbing systems.

Lastly, the A.O. Smith 3400 is a powerhouse designed for larger commercial applications. This model offers exceptional heating capacities and includes advanced technologies such as a digital display for easy monitoring and control. The robust build is complemented by a high-performance insulation system that significantly reduces energy consumption and operating costs.

All A.O. Smith water heaters, including the 2600, 2000, 1700, and 3400 models, feature corrosion-resistant materials ensuring longevity and durability. With their commitment to quality and innovation, A.O. Smith continues to provide water heating solutions that meet modern demands while emphasizing energy efficiency and user convenience. Whether for residential or commercial use, each model represents the pinnacle of reliability and performance in water heating technology.

In conclusion, A.O. Smith has established itself as a reliable choice for water heaters, with models that cater to diverse needs without compromising on efficiency or quality.