Lochinvar 400-801 operation manual Temperature control, Protection features

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8 Operating information

Temperature control

Modulation

The Outdoor Knight XL is capable of modulating its firing rate from a minimum of 20% to a maximum of 100%. The firing rate is dictated by the call for heat (i.e., space heating or domestic hot water), the heating load, ramp delay (if enabled), and various other temperature limitations.

Ramp delay

For systems with lower flow, the SMART SYSTEM can limit the firing rate (when enabled) when a space heating call for heat starts, or when switching from a DHW call for heat to a space heating call for heat. There are six (6) limits that can be programmed, as well as six (6) time intervals corresponding to each limit. The sixth limit will also limit the firing rate for the rest of the call for heat.

Gradient limiting

If during operation of the boiler the outlet water temperature is rising too quickly, the control will reduce the firing rate to its lowest setting.

Outdoor air reset

If an outdoor air sensor is connected, the control module will calculate the set points of the three (3) space heating demands based on the programmed reset curves. The installer can change the slope of the reset curves by several adjustable parameters. The user can limit the maximum set point for the system using the space heating set points.

Boost function

If outdoor air reset is active, and any space heating demand has been active continuously for a set period of time (time adjustable by installer) and there has been no DHW demands, the control will increase the set point of that demand by a fixed number of degrees (adjustable by installer). This process will continue until the space heating demand ends, the set point reaches the programmed set point or a maximum of 20 increases has occurred. Once the system heat demand is satisfied, the set point will revert to the value determined by the reset curve.

Night setback

The controller may be programmed to reduce the space heating and DHW set points during certain times each week. Seven different start and stop times may be programmed for the space heating setback and seven start and stop times for the DHW setback.

Flame current support

To prevent nuisance shutdowns when the boiler is firing at minimum rates, the control will increase the firing rate when the flame signal drops too low.

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Outdoor Knight XL Installation & Operation Manual

Protection features

Outlet temperature, flue temperature, and temperature rise limiting

The outlet temperature is monitored by the boiler outlet temperature sensor. When the outlet temperature exceeds 185°F, the unit will reduce the fan speed. If the outlet water temperature exceeds 195°F (90°C) the control will shut the unit down until it cools off.

The control module monitors the flue temperature by a sensor located in the flue exhaust. If the flue temperature exceeds 215°F (102°C) the control will reduce the maximum fan speed. If the flue temperature exceeds 240°F (115°C) the control will shut the unit down. The unit will restart automatically once the flue temperature drops 25°F (-4°C) and the minimum off time has expired.

The control monitors the temperature difference between the inlet and the outlet sensor. If this difference exceeds 55°F (13°C) the control will reduce the maximum fan speed. If the temperature difference exceeds 60°F (15°C) the control will shut the unit down. The unit will restart automatically once the temperature difference has dropped below 55°F (13°C) and the minimum off time has expired.

Freeze protection

DO NOT install the boiler in a location where it is likely to freeze.

The following integral feature of the SMART SYSTEM control module provides some protection for the boiler only -- not for the system.

•The SMART SYSTEM control module provides freeze-up protection as follows when the boiler water temperature drops below 45°F (7°C):

•Below 45°F (7°C), the boiler and system pumps operate constantly.

•Below 37°F (3°C), the boiler turns on.

•Boiler and pumps turn off if boiler water temperature rises above 45°F (7°C).

•Lower temperatures may be programmed for systems with anti-freeze solutions.

NOTICE

When system return temperatures

are maintained below the dew point,

 

condensation will form on the inside of the

 

boiler jacket causing some internal sheet

 

metal components to rust.

￿CAUTION This feature of the SMART SYSTEM control module does not eliminate the

possibility of freezing. The installation must still use recognized design, installation and maintenance practice to prevent freeze potential for the boiler and system.

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Contents Outdoor Knight XL Models 400 Contents When servicing boiler Please read before proceedingOutdoor Knight XL How it works Stainless steel heat exchangerModel Models 601 Ratings Outdoor Knight XL Boiler Ahri RatingDetermine boiler location Installation must comply withBefore locating the boiler, check Provide clearances Outdoor vent / air intake locationFlooring and foundation Prevent combustion air contaminationPrepare boiler Install flue pipe assembly Models 400Remove boiler from wood pallet 3Install flue pipe assembly Models 701 Models 7014Installing Propane Orifice Model Gas conversions ModelModels 601 Leveling the boilerHydronic piping TEE with 1 Fitting on TOP Nipple Close Nipple Flow switch adjustment Near boiler piping componentsCirculator sizing Near boiler piping connectionsVariable speed pump option Pressure Head Feet20F 25F 30F 35F Model 7Single Boiler Multiple Temperatures 8Single Boiler Primary/Secondary Piping Number of Units Manifold Pipe Sizes in Inches mm10Multiple Boilers Primary/Secondary Piping Temperature Wires to Loop Sensors 120VAC to Connecting gas supply piping Gas connectionsNatural gas Propane GasCheck inlet gas supply InchesGas valve replacement Gas pressureField wiring Installation must comply withLine voltage connections Low voltage connectionsOutdoor temperature sensor High gas pressure switchLow gas pressure switch ThermostatFlow switch Alarm contactsWiring of the cascade ModBus3Low Voltage Field Wiring Connections Condensate disposal Condensate drainFreeze protection when used Start-upCheck/control water chemistry Fill and test water systemCheck for gas leaks Check thermostat circuitsInspect/fill condensate system Inspect/check condensate lines and fittingsFinal checks before starting the boiler Start the boilerIf boiler does not start correctly Check system and boilerFor Your Safety Read Before Operating Set space heating operation Natural Gas PropaneSet domestic hot water DHW operation Verify DHW modeConfiguration of the cascade Operating information GeneralHow the boiler operates How the control module operatesTemperature control Protection featuresBoiler temperature regulation Outdoor reset operation, if used CascadeSequence of operation Operation DisplayStandby, ready to start a new cycle Access modes InstallerOutdoor Knight XL control module UserCall for Heat Information Dial Function Service technician Maintenance Maintenance and annual startupOwner maintenance Maintenance Flue vent system and air piping Check water systemCheck expansion tank Check boiler relief valveCheck ignition ground wiring Check all boiler wiringCheck control settings Inspect ignition and flame sense electrodesCheck flame signal Cleaning boiler heat exchangerReview with owner Model Kit Part Component Number DescriptionDiagrams High Voltage2Ladder Diagram
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400-801 specifications

The Lochinvar 400-801 is a high-efficiency commercial boiler that embodies advanced engineering and cutting-edge technology. Designed for a variety of commercial applications, this boiler is known for its reliability, efficiency, and robust performance.

One of the standout features of the Lochinvar 400-801 is its high thermal efficiency, which can reach up to 99%. This efficiency not only reduces fuel consumption but also lowers operating costs, making it an economical choice for businesses seeking to minimize overhead. The boiler employs a stainless steel fire-tube heat exchanger that ensures optimal heat transfer and durability. This construction allows for enhanced resistance to corrosion, thereby extending the boiler's lifespan.

The Lochinvar 400-801 is equipped with advanced control technologies that enhance its performance. With its built-in SMART SYSTEM control, users can easily monitor and manage the boiler’s operations, optimizing performance while ensuring ease of use. This control system features a user-friendly interface that provides real-time data, including temperature settings, pressure readings, and operational status, allowing for quick diagnostics and efficient troubleshooting.

Safety is paramount in the design of the Lochinvar 400-801. The boiler includes a comprehensive safety system that incorporates multiple safety interlocks and a venting system that prevents backflow and ensures safe exhaust. Moreover, the unit is designed to operate with minimal noise, making it suitable for environments where noise reduction is crucial.

Installation and maintenance of the Lochinvar 400-801 are straightforward, thanks to its compact design and multiple venting options. The low-profile construction allows for flexibility in placement, making it an ideal fit for tight spaces. Maintenance tasks are simplified with accessible components, minimizing downtime and ensuring the system operates efficiently over its lifespan.

In conclusion, the Lochinvar 400-801 stands out in the commercial boiler market with its blend of efficiency, reliability, and innovation. With its advanced technologies and features, businesses can achieve significant energy savings while ensuring comfortable and consistent heat for various applications. The Lochinvar 400-801 is an investment in quality and performance, backed by a well-established brand in the heating industry. Whether for a new installation or a replacement, this boiler offers a comprehensive solution for commercial heating needs.
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