Lochinvar WH 55-399 System supply sensor, Boiler management system, Runtime contacts

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8 Field wiring

System supply sensor

1.By installing the system supply sensor into the supply of the primary loop, the temperature of the primary supply can be controlled. The SMART SYSTEM control automatically detects the presence of this sensor, and controls the boiler firing rate to maintain the system supply temperature to the set point (if the outlet sensor control is currently selected). If it is desired to control the system return temperature, then program the SMART SYSTEM control to use the inlet sensor as the controlling sensor. See the Knight Wall Mount Service Manual for instructions on how to do this. When the inlet sensor is programmed as the controlling sensor, it is strongly recommended that the SYSTEM SUPPLY sensor be installed. DO NOT INSTALL THE SYSTEM SUPPLY SENSOR INTO THE SYSTEM RETURN.

2.The TST2032 sensor provided with the boiler must be used for the system sensor.

3.Connect these terminals to the system supply sensor (FIG. 8-4).

Boiler management system

1.An external control may be connected to control either the firing rate or the set point of the boiler. If the external control uses a set of contacts to enable the boiler, connect the contacts to the Heat/Loop Demand 1 terminals. Otherwise, the SMART SYSTEM control will be enabled by the 0-10V signal.

2.Make sure the (-) terminal is connected to the (-) or common output terminal of the external control, and

the (+) terminal is connected to the 0 - 10 vdc or (+) terminal of the external control. Make sure the (-) voltage is not below ground.

Runtime contacts

The SMART SYSTEM control closes a set of dry contacts whenever the burner is running. This is typically used by Building Management Systems to verify that the boiler is responding to a call for heat.

Alarm contacts

The SMART SYSTEM control closes another set of contacts whenever the boiler is locked out or the power is turned off. This can be used to turn on an alarm, or signal a Building Management System that the boiler is down.

Installation & Operation Manual

Wiring of the cascade

When wiring the boilers for Cascade operation, select one boiler as the Leader boiler. The remaining boilers will be designated as Members. See page 63 “Configuration of the Cascade” for a detailed explanation of this procedure.

Connect the system supply sensor and outdoor air sensor (if used) to the Leader boiler. For the Cascade system to work properly the system supply sensor must be installed. The location of the system supply sensor should be downstream of the boiler connections in the main system loop (FIG.’s 6-4 and 6-6). The system supply sensor should be wired to the Low Voltage Connection Board at the terminals marked for the system sensor (see FIG. 8-4). The Leader control will use the water temperature at the system supply sensor to control the operation of the Cascade.

If outdoor air reset is desired, the outdoor air sensor should be wired to the Low Voltage Connection Board at the terminals marked for the outdoor air sensor (FIG. 8-4). If the outdoor air sensor is connected, the Leader control will calculate the water temperature set point based on the programmed reset curve parameters. If the outdoor air sensor is not connected, the Leader control will maintain the fixed water temperature set point that is programmed into the control.

If a Thermostat, Zone Control enable output, or Building Management System enable output is available, it should be wired to the Low Voltage Connection Board on the Leader boiler at the terminals marked for one of the Heat/Loop Demands 1-3 (FIG. 8-4). If the boilers are to run continuously, connect a jumper wire between the R and W terminals for the Heat/Loop demand input. This will initiate a call for heat on the Cascade.

Communication between the Leader boiler and the Member boilers is accomplished by using shielded, 2-wire twisted pair communication cable. Connect one of the twisted pair wires to Cascade terminal A on each of the Low Voltage Connection boards, and the other wire of the twisted pair to Cascade terminal B on each of the Low Voltage Connection Boards. Connect the shield wires to one of the shield terminals on the Low Voltage Connection Boards (FIG. 8-4). If more than two boilers are on the Cascade, daisy chain the wiring from the Cascade terminals on the second boiler to the Cascade terminals on the third boiler, then from the third to the forth, and so on. The connections between boilers can be made in any order, regardless of the addresses of the boilers. Try to keep each cable as short as possible.

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Contents Models WH 55 Contents Boiler operation When servicing boilerPlease read before proceeding Boiler waterKnight Wall Mount Boiler How it works Stainless steel heat exchangerModels 55 Ratings Knight Wall Mount Boiler Ahri RatingDetermine boiler location Installation must comply withCloset and alcove installations Before locating the boiler, check1Closet Installation Minimum Required Clearances Wall mounting location PrecautionsVent and air piping Prevent combustion air contaminationWhen using an existing vent system to install a new boiler Products to avoidAreas likely to have contaminants When removing a boiler from existing common vent system Prepare boiler Remove boiler from wood palletGas conversions Mounting to a concrete wall Mounting the boilerMounting to a wood studded wall Mounting to a metal studded wallGeneral venting Direct venting options Sidewall VentInstall vent and combustion air piping Air intake/vent connectionsModel Kit Number Equivalent Vent Length Requirements for installation in CanadaSizing Model Max Vent AirMaterials Air inlet pipe materialsOptional room air Air contaminationVent pipe Approved PVC/CPVC Vent Pipe and FittingsMaterial Standard Vent fittingsModel PolypropyleneCentrotherm InnoFlue SW Duravent Polypro Stainless steel vent Vent/air termination sidewall If using the alternate sidewall terminationSidewall direct venting Determine location2AClearance to Gravity Air Inlets Model Air Vent Centerline Width Prepare wall penetrationsPrepare wall penetrations Alternate Field Supplied Option Multiple vent/air terminationsSidewall termination installation Sidewall termination optional concentric ventDescription and usage 92 and 3 Concentric Vent Dimensional Drawing reference D on Sidewall termination optional concentric vent models12Concentric Vent Sidewall Attachment Multiventing sidewall terminationsVertical direct venting Vent/air termination verticalPrepare roof penetrations Vertical termination installation Vertical termination optional concentric ventMultiventing vertical terminations Minimum Combustion AIR TypicalConcentric Venting Arrangement Alternate vertical concentric ventingVent / Air Inlet Size Minimum Existing Vent / Chase Size Existing vent as a chaseLow water cutoff device Hydronic pipingSystem water piping methods General piping information Chilled water systemNear boiler piping components Near boiler piping connections Circulator sizing35F Temperature Rise Applications 20F Temperature Rise Applications25F Temperature Rise Applications Pump Size GrundfosSmart System / Multi-temperature loop control option Variable speed pump setupVariable speed pump option 3Single Boiler Primary / Secondary Piping Make UP Water Indirect Number of Units Boiler Member 8Single Boiler Multiple Temperature DHW Priority Model Required Pipe Sizes Boiler Make UP Boiler Connecting gas supply piping Gas connectionsNatural gas Propane GasNatural Gas Pipe Capacity Chart Check inlet gas supplyLength of Pipe in Straight Feet for 1/2 PSI Gas valve replacement Gas PressureField wiring Installation must comply with Low voltage connectionsLine voltage connections Flow switch Outdoor temperature sensorLouver proving switch ThermostatSystem supply sensor Alarm contactsWiring of the cascade Boiler management systemInstallation FieldwiringCondensate disposal Condensate drainCheck/control water chemistry Freeze protection when usedStart-up Fill and test water systemCheck thermostat circuits Clean/Inspect Trap AssemblyCheck for gas leaks Inspect/fill condensate system Inspect/check condensate lines and fittingsIf boiler does not start correctly Final checks before starting the boilerStart the boiler Check system and boiler2Operating Instructions Models 55 Operating Instructions Model Set space heating operation Natural Gas PropaneVerify DHW mode Configuration of the cascadeSet domestic hot water DHW operation Operating information GeneralProtection features Boiler temperature regulation Outdoor reset operation, if used CascadeSequence of operation Operation DisplayAccess modes InstallerUser Knight wall mount boiler control module 1Control PanelCall for Heat Information Dial Function Owner maintenance Maintenance Maintenance and annual startupService technician See the following pages for instructions GeneralMaintenance Check control settings Check ignition ground wiringCheck all boiler wiring Flue vent system and air pipingPerform start-up and checks Check flame signalCleaning boiler heat exchanger Check burner flameDiagrams PC Interface2Wiring Diagram

WH 55-399 specifications

The Lochinvar WH 55-399 is a high-efficiency water heater designed for residential and commercial applications, offering a reliable solution for hot water needs. This model represents an advanced approach to water heating, combining cutting-edge technologies and features that ensure optimal performance and energy efficiency.

One of the standout features of the Lochinvar WH 55-399 is its high thermal efficiency, which is a key factor in reducing energy consumption and operating costs. With an efficiency rating exceeding 90%, this water heater ensures that more energy is converted into usable hot water, making it an environmentally friendly choice.

The WH 55-399 utilizes advanced condensing technology, which allows it to extract additional heat from the exhaust gases before they are expelled. This process not only increases efficiency but also significantly decreases greenhouse gas emissions. The unit is also equipped with an intelligent control system that allows for precise temperature adjustments, ensuring that the user has an optimal supply of hot water while maintaining energy savings.

Another important aspect of this model is its impressive recovery rate. The ability to quickly heat water after a significant draw ensures that users will not experience interruptions in their hot water supply, making it ideal for busy households or commercial environments. This is particularly beneficial in applications requiring consistent hot water availability, such as restaurants or athletic facilities.

The Lochinvar WH 55-399 is designed with durability in mind. Constructed from high-quality materials, this water heater boasts a robust tank lined with corrosion-resistant coatings, extending the lifespan of the unit and reducing maintenance needs. Additionally, it features a reliable gas burner and a well-insulated tank, contributing to its overall efficiency and performance.

Safety is also a priority with the WH 55-399. The unit incorporates multiple safety features, including a flame sensor, automatic shut-off valve, and over-temperature protection, ensuring peace of mind for users.

In summary, the Lochinvar WH 55-399 stands out with its combination of high efficiency, advanced technology, and durable construction. Whether for residential or commercial use, this water heater provides a dependable and cost-effective solution for all hot water needs. Its innovative design and performance characteristics make it a top choice for anyone seeking a premium water heating option.
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