Bradford-White Corp BNTH, BNTV Domestic Hot Water Heating Using External Modulation Control

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BRADFORD WHITE CORP.

 

 

 

 

firing rate is controlled by the DHW setpoint temperature and the water temperature at the heat exchanger outlet. Once the DHW call is supplied the control starts the boiler and DHW pumps and begins the ignition process. The ignition process consists of a prepurge, trial for ignition, and run period. The prepurge period starts on a call for heat once the fan RPM reaches a preset level. The trial for ignition period follows once the start-up RPM of the fan is reached. The trial for ignition period lasts 4 seconds during which the direct spark ignition system and gas valve are energized. At the end of the trial for ignition period the flame signal is compared with the preset flame threshold value. If the flame signal is higher than the flame threshold the Brute Elite enters "run". If the flame signal is below the threshold the Brute Elite returns to prepurge and starts the ignition process over. In "run" the Brute Elite monitors the flame signal, call for heat, safeties, and water temperatures modulating as needed between 100% and 20% of rate to satisfy the call for heat.

9.9Domestic Hot Water Heating Using External Modulation Control

When using the Brute Elite for DHW heating with external modulation control a call for heat must be supplied to the "T-T or Interlock" terminal. By supplying a call to the "T-T or interlock" terminal the operating temperature setpoint defaults to the hydronic heating setpoint, so all of the temperature adjustments must be made to the hydronic setpoint. Once the call is supplied, the control starts the boiler and system pumps and begins the ignition process.

The ignition process consists of a prepurge, trial for ignition, and run period. The prepurge period starts on a call for heat once the fan RPM reaches a preset level. The trial for ignition period follows once the start-up RPM of the fan is reached. The trial for ignition period lasts 4 seconds during which the direct spark ignition system and gas valve are energized. At the end of the trial for ignition period the flame signal is compared with the preset flame threshold value. If the flame signal is higher than the flame threshold the Brute Elite enters "run". If the flame signal is below the threshold the Brute Elite returns to prepurge and starts the ignition process over. In "run" the Brute Elite monitors the flame signal, call for heat, safeties, and water temperatures. The heater setpoint is used to limit the maximum water temperature leaving the boiler only. The modulation rate is controlled by a 4-20mA (0-10Vdc using converter) signal supplied by an external control. When setting up a system using an external control care must be taken to set the external control algorithms to prevent the boiler from short cycling or "hunting " to prevent prema- ture component failure.

9.10Domestic Hot Water Heating Using Local Lead-Lag/Cascading Feature

When using multiple Brute Elites to supply Domestic hot water only the heaters should be setup as stated in Section 8.12 “Lead/Lag Cascading,” and Section 9.5 “Hydronic Heating Using Local Lead/Lag Cascading Feature.” When the heaters are installed in this fashion, all of the setpoints and adjustments are done through the Lead Lag menus.

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Contents Installation and Operation Instructions for Installation and Operation InstructionsDocument BRUTE ELITESECTION TABLE OF CONTENTSBrute Elite Control Setup and Operation General InformationReplacement Parts SECTION MaintenanceTrouble Shooting SECTION Modes of Operation1.2 Model Identification SECTION General Information1.1 Introduction Model NomenclatureFigure 1. Location of Components, Sizes Figure 2. Location of Components, SizesFigure 3. Location of Components, Size Figure 4. Location of Components, SizeFigure 5. Location of Components, Size Figure 6. Location of Components, SizeFigure 7. Location of Components, Sizes 750 and 1.3 Appliance Overview 1.4 Warranty1.6 Dimensions 1.5 UnpackingFigure 9. Dimensional Drawing, Sizes Dimensions are nominal and are shown in inches, cmBrute Elite is for indoor installations only SECTION Locating the Appliance2.1 Locating the Appliance 3.1.1 Combustion Air From Room SECTION Venting and Combustion Air3.1 Combustion Air 3.1.2 Ducted Combustion Air3.2 Venting Figure 10. Combustion Air and Vent Through RoofTable 5. Required Exhaust Vent Material A. exhaust vent terminal not included 3.3 Locating Vent & Combustion Air Terminals3.2.1 Venting Requirements Unique to Canada E. CPVC exhaust pipe section 80-500 not incl5. For concentric vent, follow instructions included with vent kit 3.3.5 Installations in the Commonwealth of Massachusetts3.3.2 Side Wall Combustion Air Terminal 3.3.3 Vertical Vent TerminalFigure 12. Combustion Air and Vent Through Side Wall 3. Signage 3.4 Common Vent Test2. Approved Carbon Monoxide Detectors 4. InspectionSECTION Gas Supply and Piping 4.1 Gas Supply and Piping3. Refer to Tables 6A, 6B, 6C and 6D to size piping 5.2 Brute Elite Water Heater Flow and Head Requirements see Table SECTION Pump Requirements5.1 Brute Elite Boiler Flow and Head Requirements see Table Table 6ASECTION 6A Water Connections - BNTH Boiler 6A.1 BNTH System Piping Hot Supply Connections6A.2 BNTH Cold Water Make-Up 6A.5 Recognized Chemicals 6A.4 BNTH Suggested Piping Schematics6A.3 Freeze Protection 1. Sentinel Performance Solutions Group 2. Hercules Chemical CompanyFigure 15. Hydronic Piping - Single Boiler zoning with circulators Brute Elite Figure 17. Hydronic Piping - Multiple Boilers zoning with circulators Brute Elite PagePage Brute Elite PagePage 6B.2 Piping Requirements SECTION 6B6B.1 BNTV Water Quality Water Connections - BNTV Water Heater6B.4 Freeze Protection 6B.5 BNTV Suggested Piping Schematics6B.3 Cold Water Make-Up 6B.6 BNTV Suggested PumpsCaution Pump sizing must be based opon Figure 25. DHW Piping, Two Heaters, One Vertical TankFigure 26. DHW Piping, Two Heaters, Two Vertical Tanks water hardness at job site7.1 Main Power SECTION Electrical Connections7.3 24Vac Transformer with Integral Circuit Breaker 7.10 Lead Lag/ Cascading Wiring Connections7.2 Pump Connections 7.4 Hydronic Call for HeatFigure 28. Lead-Lag / Cascading Wiring Connections 7.11 Wiring Diagrams see Figures 29 and Figure 29. Ladder DiagramFigure 30. Wiring Diagram all sizes SECTION Brute Elite Control Setup and Operation 8.1 Display Navigation8.2 Ignition Control- Sequence of Events 8.5 High Limit 8.3 Modulation Control8.5 Anti-Short Cycle ASC 8.7 Outlet Water Temperature8.12.1 Lead Lag Setpoint 8.12.5 Lead Lag Base Load Setting8.13 Boiler Pump Interrupt 8.12.2 Lead Lag Master/Slave SelectionSECTION Modes of Operation 9.2 Hydronic Heating with Outdoor Reset9.4 Hydronic Heating Using External Modulation Control 9.1 Hydronic Heating Demand9.8 Domestic Hot Water Demand BNTV only 9.5 Hydronic Heating Using Local Lead- Lag/Cascading Feature9.7 Warm Weather Shutdown Let’s consider the following example9.9 Domestic Hot Water Heating Using External Modulation Control 10.1 Filling the Boiler System 10.2 Operating the Burner and Set UpSECTION Operating Instructions 10.2.1 Burner Operation10.4 To Restart Brute Elite 10.2.2 Boiler Setup and Adjustment10.3 Shutting Down Brute Elite 3. WAIT FIVE 5 MINUTES80-285 Figure 33A. Brute Elite Gas Valves 285, 399 andFigure 33B. Brute Elite Gas Valves 600, 750 and 11.2 Appliance Maintenance and Component Description SECTION Maintenance11.1 System Maintenance yearly, unless otherwise noted11.2.4 Ignitor Assembly 11.2.5 Flame SensorIgniters and sensors get hot and can cause burns or injury 11.2.6 Transformer with Integral Circuit Breaker 11.2.7 Blower11.2.8 Heat Exchanger Coils 11.2.9 Gas Pressure Switches optional SECTION Trouble Shooting12.3 Error Codes - See Table 12.1 Sequence of Operationcontinued next page PROBLEMSOLUTION CODE#Table 18. Error Codes see Section13.1 General Information SECTION Replacement Parts13.2 Parts List Jacket Components - See FigureGas Train Components - See Figure Heat Exchanger Components - See Figure Contact Customer Service at 800 900-9275 Electrical Components - See FigureFigure 35. Jacket Components Figure 36A. Internal Components, Sizes Figure 36B. Internal Components, SizesFigure 36C. Internal Components, Sizes Figure 37A. Gas Train Components, Sizes Figure 37B. Gas Train Components, Sizes Figure 38. Heat Exchanger Components Figure 39. Electrical Components Brute Elite Warranty Service 800 Tech. Service 800Service Parts 800 Ambler, PA
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