Bradford-White Corp BRHHH Temperature Control Features, Internal Water Heater Temperature Control

Page 25

Βρυτε Μαγνυμ

Page 25

 

temperature is less than 140°F (60°C), internal mixing will keep the outlet temperature at 160-165°F (71- 74°C), and this will mix with the tank temperature to maintain a lower temperature in the tank. If the return temperature is 140°F (60°C) or higher, the outlet temperature of the heater will be the return temperature plus 20-25°F (11-14°C) when the Brute Magnum is at high firing rate.

The manual reset high limit is on the outlet of the Brute Magnum. Set the manual reset high limit at about 20°F (11°C) higher than the highest expected outlet temperature, to avoid nuisance lockouts

5.4.2Internal Water Heater

Temperature Control

When an external control is not used, the circulator between the heater and the storage tank must run continuously, so that the heater’s temperature control can detect and control the water temperature in the storage tank. The Brute Magnum water heater’s temperature control is adjusted to its lowest temperature position when shipped from the factory. This is the preferred starting point for setting the temperature control.

The Brute Magnum temperature control measures temperature on the heater inlet, sensing return water temperature. If the return water temperature is less than 140°F (60°C), internal mixing will keep the outlet temperature at 160-165°F (71-74°C), and this will mix with the tank temperature to maintain a lower temperature in the tank. If the return temperature is 140°F (60°C) or higher, the outlet temperature of the heater will be the return temperature plus 20-25°F (11- 14°C) when the Brute Magnum is at high firing rate.

The manual reset high limit is on the outlet of the Brute Magnum. Set the manual reset high limit at about 20°F (11°C) higher than the highest expected outlet temperature, to avoid nuisance lockouts.

Caution

Should overheating occur or the gas supply fail to shut off, turn off the manual gas control valve to the appliance.

The offset determines where the throttling range begins.

The throttling range is the temperature range through which the unit will modulate from minimum to maximum firing rate.

Important Note: These control parameters work together. Therefore, setting one parameter may have an affect on another. Figures 14, 15 and 16 show the relationships between these settings. Figure 14 follows the examples that are shown in the following sections, and Figures 15 and 16 are examples of how the parameters can interfere with each other.

5.5.1Temperature Setpoint

The temperature setpoint is the point at which the temperature control relay will be de-energized and the unit’s call for heat will end. The temperature setpoint is adjusted with the setpoint dial on the A350 control (see Figure 13). The temperature control’s sensor is in the inlet of the unit.

Note: Jumper must be in “Reverse Acting” mode, or unit will not operate properly.

Figure 13. Proportional Control.

5.5Temperature Control Features

The Brute Magnum temperature control is

versatile and will allow the user to better match the modulating control to the application. Settings that can be changed are temperature setpoint, differential, offset, throttling range, and minimum output.

The temperature setpoint is the setting at which the unit will shut off, having satisfied the controller’s call for heat.

The differential determines how far the temperature in the Brute Magnum can fall before energizing again.

5.5.2Differential Setting

The differential is the difference in temperature settings when the temperature control’s relay is energized and de-energized. For instance, if the temperature setpoint is 120°F (49°C) and the differential is 20°F (11°C), the temperature control will call the unit to energize at 100°F (38°C). (The differential is the setpoint minus the differential setting) The call for heat will end when the unit reaches its setpoint of 120°F (49°C). The Brute Magnum differential is adjustable from 1°F to 30°F (1°C to 17°C). In general, the differential setting for a water heater system will be low, so that when a storage

Image 25
Contents Βρυτε Μαγνυμ Βραδφορδ Ωηιτε Χορπ Maintenance Table of ContentsTroubleshooting Replacement PartsList of Figures List of TablesIntroduction General InformationModel Identification Model DesignationDimensions WarrantyLocating the Appliance Inches 91cm horizontally Combustion Air Venting and Combustion AIRCombustion Air From Room Intake Combustion AirLocating Vent & Combustion Air Terminals VentingHorizontal Vent Terminal Combustion Air and Vent Through Side Wall From Massachusetts Rules and Regulations 248 CMR Installation of Carbon Monoxide DetectorsSide Wall Combustion Air Terminal Common Vent Test BoilersVertical Vent Terminal Vertical Combustion Air TerminalDistance from Gas Meter or Last Stage Regulator GAS Supply and Piping4A.1 Heating System Piping Hot Supply Connections Boiler Water Connections Brute Magnum Boiler4A.2 Cold Water Make-Up Boiler 4A.3 Freeze Protection Boiler Water Connections Brute Magnum Water Heater4B.1 Water System Piping Water Heater 4B.2 Hot Water Supply Piping Water HeaterHydronic Piping Multiple Boilers 4B.3 Water Flow Requirements Water HeaterHydronic Piping Multiple Boilers Alternate 4B.4 Combined Water potable Heating and Space Heating Hydronic Piping One Boiler, Multi-Temperature System4B.5 Freeze Protection Water Heater Heater or in the pipes in the system. When waterWater Heater Piping One Heater, One Tank Water Heater Piping Multiple Heaters, One Tank Water Heater Piping One Heater, Multiple Tanks Water Heater Piping Multiple Heaters, Multiple Tanks Temperature Control Boiler Main PowerTemperature Control Water Heater Electrical ConnectionsInternal Water Heater Temperature Control Temperature Control FeaturesTemperature Setpoint Differential SettingThrottling Range OffsetIntegration Constant Minimum Output SettingControl Parameter Possible Interference Mixing System and ControlExternal Control Connections Wiring DiagramsWiring Diagram, Size 1200, Standard and Codes a and F Βρυτε Μαγνυμ Wiring Diagram, Size 1200, Code B Wiring Diagram, Sizes 1600, 2000 and 2400, Code B Wiring Schematic, Model 1200, Standard and Codes a and F Wiring Schematic, Model 1200, Code B Operating Instructions Operating the Burner and Set UpFilling the Boiler System Gas/Air Test Panel System Maintenance MaintenanceAppliance Maintenance Component Description Shutting Down the Brute MagnumGas Trains Filter BurnerModulating Gas Valve Manual Reset High Limit Control Safety Gas ValveAuto Reset Temperature Limit Mixing ControlFlow Switch Ignitor / Flame Sensor AssemblyMixing Actuator Ignition ControlMotorized Safety Valve TroubleshootingGas Pressure Switches Sequence of OperationResolving Lockouts Delayed Ignition Possible CausesShort Cycling Boiler Short Cycling Water Heater Replacement PartsHigh Gas Consumption Combustion Components See Figure Parts ListElectrical Components See Figure Jacket See Figure Combustion Components Gas Train/Combustion Air Components Gas Train Components Electrical Components Heat Exchanger / Water Path Components Heat Exchanger / Water Path Components Jacket Components Litho in U.S.A. Bradford White 1102 Document