Lochinvar 400-801 ModBus, Flow switch, System supply sensor, Boiler management system

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5 Field wiring

ModBus

When the optional ModBus interface module is installed, the RS-485 ModBus cable is connected to these terminals. Use shielded, 2-wire twisted pair cable. If desired, the shield can be connected to ground by installing a jumper wire between terminals 1 and 3 on connector X5 on the optional ModBus interface module.

Flow switch

1.A flow switch is used to guarantee flow through the boiler before allowing it to fire. The flow switch must be installed at the boiler outlet.

2.Remove the jumper wire from the terminals on the connection board and connect these terminals to the normally open contacts on the flow switch (FIG. 5-3).

System supply sensor

1.By installing the system supply sensor into the supply of the primary loop, the temperature of the system 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). See the Outdoor Knight XL Service Manual for instructions on how to use the inlet sensor as the controlling sensor. When the inlet sensor is programmed as the controlling sensor, it is vital 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. 5-3).

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 that 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.

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Outdoor Knight XL Installation & Operation Manual

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.

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 36 “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 3-7 through 3-11). The system supply sensor should be wired to the Low Voltage Connection Board at the terminals marked for the system sensor (see FIG. 5-3). 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. 5-3). 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 or Zone Control 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. 5-3). 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. 5-3). 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
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 RatingInstallation must comply with Determine boiler locationBefore locating the boiler, check Flooring and foundation Provide clearancesOutdoor vent / air intake location Prevent combustion air contaminationInstall flue pipe assembly Models 400 Prepare boilerRemove 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 componentsNear boiler piping connections Circulator sizingVariable speed pump option Head Feet Pressure20F 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 pressureLine voltage connections Field wiringInstallation must comply with Low voltage connectionsLow gas pressure switch Outdoor temperature sensorHigh gas pressure switch ThermostatWiring of the cascade Flow switchAlarm contacts ModBus3Low Voltage Field Wiring Connections Condensate disposal Condensate drainCheck/control water chemistry Freeze protection when usedStart-up Fill and test water systemInspect/fill condensate system Check for gas leaksCheck thermostat circuits Inspect/check condensate lines and fittingsIf boiler does not start correctly Final checks before starting the boilerStart the boiler Check system and boilerFor Your Safety Read Before Operating Set space heating operation Natural Gas PropaneVerify DHW mode Set domestic hot water DHW operationConfiguration of the cascade How the boiler operates Operating informationGeneral 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 Outdoor Knight XL control module Access modesInstaller UserCall for Heat Information Dial Function Maintenance Maintenance and annual startup Service technicianOwner maintenance Maintenance Check expansion tank Flue vent system and air pipingCheck water system Check boiler relief valveCheck control settings Check ignition ground wiringCheck all boiler wiring Inspect ignition and flame sense electrodesReview with owner Check flame signalCleaning boiler heat exchanger Model Kit Part Component Number DescriptionDiagrams High Voltage2Ladder Diagram